TWI424645B - Method and apparatus for stabilizing and tuning the bandwidth of laser light - Google Patents
Method and apparatus for stabilizing and tuning the bandwidth of laser light Download PDFInfo
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本揭露標的是關於(例如)一DUV氣體放電雷射系統(例如,用於(例如)一譜線窄化應用的一準分子或氟分子雷射系統)內的帶寬之主動控制,例如作為以光刻製造的積體電路之一雷射光源。The subject matter is directed to active control of bandwidth within, for example, a DUV gas discharge laser system (eg, an excimer or fluorine molecular laser system for, for example, a line narrowing application), for example, A laser source of one of the integrated circuits fabricated by photolithography.
穩定帶寬(例如,用於DUV半導體積體電路光刻雷射光源設計之E95 )包括被動及主動帶寬控制。主動控制可使此等光源受益於光學效能校正(“OPC”)及工具對工具匹配此類的光源。序列號為60/923,486的美國臨時專利申請案(名稱為“TWO STAGE EXCIMER LASER WITH SYSTEM FOR BANDWIDTH CONTROL”,於2006年4月13日提出申請)包括序列號為11/510,037的美國專利申請案(名稱為“ACTIVE SPECTRAL CONTROL OF DUV LIGHT SOURCE”,於2006年8月25日提出申請,於2007年8月23日公開,公開號為US-2007-0195836-A1)之揭露,其主張序列號為60/774,770的美國臨時申請案(名稱為“ACTIVE SPECTRAL CONTROL OF DUV LIGHT SOURCES FOR OPE MINIMIZATION”,於2006年2月17日提出申請)之優先權,此等申請案中的每個之揭露以參照方式被併入本文。序列號為11/510,037的申請案揭露了一種使用粗及細控制致動 器的多級帶寬控制系統。Stable bandwidth (eg, E 95 for DUV semiconductor integrated circuit lithography laser source design) includes passive and active bandwidth control. Active control allows these sources to benefit from optical performance correction ("OPC") and tool-to-tool matching of such sources. US Provisional Patent Application Serial No. 60/923,486, entitled "TWO STAGE EXCIMER LASER WITH SYSTEM FOR BANDWIDTH CONTROL", filed on April 13, 2006, includes U.S. Patent Application Serial No. 11/510,037 ( The name is "ACTIVE SPECTRAL CONTROL OF DUV LIGHT SOURCE", filed on August 25, 2006, published on August 23, 2007, the disclosure of which is US-2007-0195836-A1, which claims Priority of US Provisional Application No. 60/774,770 (named "ACTIVE SPECTRAL CONTROL OF DUV LIGHT SOURCES FOR OPE MINIMIZATION", filed on February 17, 2006), the disclosure of each of these applications is incorporated by reference. The method is incorporated herein. The application of Serial No. 11/510,037 discloses a multi-stage bandwidth control system using coarse and fine control actuators.
本申請案揭露了作為一致動器的光柵彎曲(使光柵彎曲的一帶寬控制設備“BCD”之位置)以及其他致動器之使用。致能帶寬穩定的各種技術被討論。主動帶寬控制系統可使用非常精確的板上頻譜測量(例如,E95 )以及帶寬錯誤回饋。基於其他雷射參數/輸出信號(例如,目標能量及工作週期)的補償可致能控制各種帶寬選擇致動器(actuators),包括低頻率大幅值致動器以及一高頻率小幅值致動器。The application discloses grating bending as an actuator (the position of a bandwidth control device "BCD" that bends the grating) and the use of other actuators. Various techniques for enabling bandwidth stabilization are discussed. Active bandwidth control systems can use very accurate on-board spectrum measurements (eg, E 95 ) and bandwidth error feedback. Compensation based on other laser parameters/output signals (eg, target energy and duty cycle) can enable control of various bandwidth selection actuators, including low frequency large value actuators and a high frequency small amplitude actuation Device.
一光刻光源雷射(一多輸入多輸出(MIMO)隨時間變化的非線性系統)可使用一(複數)致動器,除了改變帶寬之外,該(等)致動器本身可能對雷射效能引起其他影響(被期望的或不被期望的)。包括具有利用個別操作參數輸入(致動器)影響雷射行為的多階(例如,雙階致動器設計)一起運作時可被最佳化以回應一(複數)特定類別的干擾。干擾可藉由時標(time scale)及/或影響之大小被分類。脈衝能量設定可包括低幅值快時標干擾(在一細致動範圍內一般為毫秒至秒)。工作週期設定點及氟氣消耗(以小時為時標)變化之高(以秒為時標)及低(小時)頻率層面可能引起較大的幅值影響。其他長期參數變化、元件老化及錯誤對準(天至周或者甚至更長)可導致最大的幅值(在一粗致動範圍)變化。A lithographic source laser (a multiple input multiple output (MIMO) time varying nonlinear system) can use a (complex) actuator, except that the bandwidth is changed, the actuator itself may be thunder Shooting performance causes other effects (expected or undesired). Multi-step (e.g., dual-order actuator design), including the use of individual operational parameter inputs (actuators) to affect laser behavior, can be optimized to respond to a (plural) specific class of interference. Interference can be classified by time scale and/or size of influence. The pulse energy setting can include low amplitude fast time scale interference (typically milliseconds to seconds in a fine actuation range). The high duty cycle (in seconds) and the low (hour) frequency level of the duty cycle set point and fluorine gas consumption (in hours) may cause large amplitude effects. Other long-term parameter changes, component aging, and misalignment (day to week or even longer) can result in a change in maximum amplitude (in a coarse actuation range).
因此,被分類到粗致動及細致動的控制動作被揭露,各自使用一或多個參數變化致動器。其中一者著重於大幅值低頻率干擾(大的E95 設定點變化、氣體老化影響及工作週期變化之長時標元素--(例如)自慢的熱負載變化、雷射元 件之使用時間增加及類似者產生)。另一者可著重於較小幅值較高頻率干擾(輸出脈衝能量以及工作週期變化之快元素--(例如)自較快的熱負載暫態及類似者產生)。該粗致動器也可用以解飽和或者重新定位中心,一(複數)細致動器在其控制範圍內。Thus, control actions classified into coarse actuation and fine actuation are disclosed, each using one or more parameter change actuators. One of them focuses on large-value low-frequency interference (large E 95 set point changes, gas aging effects, and long time-scale elements of duty cycle changes)—for example, slow self-heating load changes, increased use time of laser components, and Similar to it). The other can focus on smaller amplitude higher frequency interference (output pulse energy and fast elements of duty cycle change - for example, from faster thermal load transients and the like). The coarse actuator can also be used to desaturate or reposition the center, with one (plural) fine actuator being within its control range.
粗致動器(例如,F2 氣體注入)及細致動器(△tMOPA )(光柵彎曲或者其他前波一致調整或者可對光束調整孔徑等)被顯示以調整帶寬且一起用於帶寬控制,具有對其他雷射參數之各種影響以及測量之時間架構以供回饋及允許解耦合之致動。詞語dtMOPA或△tMOPA 或者差動發射時間或者差動放電時序或差動計算控制(如此處所使用的)都是以下概念之簡化符號:在種源雷射電極與放大器雷射電極之間的放電計時以選擇性地放大在該放大器增益媒體內的種源雷射脈衝之一部分,從而選擇該雷射光源之輸出的帶寬。注意到需要足夠的致動範圍以能夠解決來自由於長期工作週期變化、氣體老化及元件老化的一般需要被抑制的此等影響之帶寬偏差。由於其他雷射操作參數引起的誤差信號變化(濾波及其他正規化)該等控制器可被補償/減少敏感度。A coarse actuator (for example, F 2 gas injection) and a fine actuator (Δt MOPA ) (grating bending or other front wave uniform adjustment or beam adjustment aperture, etc.) are displayed to adjust the bandwidth and together for bandwidth control, There are various effects on other laser parameters and the time frame of the measurement for feedback and actuation of the decoupling. The term dtMOPA or Δt MOPA or differential emission time or differential discharge timing or differential calculation control (as used herein) is a simplified notation for the following concept: discharge between a source laser electrode and an amplifier laser electrode Timing to selectively amplify a portion of the source laser pulse within the amplifier gain medium to select the bandwidth of the output of the laser source. It is noted that a sufficient range of actuation is required to be able to address bandwidth deviations from such effects that are generally suppressed due to long term duty cycle variations, gas aging, and component aging. These controllers can be compensated/reduced for sensitivity due to error signal changes (filtering and other normalization) caused by other laser operating parameters.
入射到一中心波長選擇光學元件(例如,分散光柵)上的一光束之可變放大也可能影響光源之帶寬。此一系統在序號為6,393,037的美國專利(於2002年5月21日被發證給Basting等人)中被討論,此專利之內容以參照方式被併入本文。Basting之摘要描述了一包括角度分散光學元件(光柵)的可調諧雷射以及一包括在一譜線窄化模組內的一或兩個 旋轉稜鏡的擴束器以調整帶寬。複數稜鏡擴束器(當兩個被使用時)被揭露以機械地彼此連接,因此當該放大變化時,該分散元件上的光束之入射角沒有被改變。此配置使得非常難以(若不是不可能的)利用旋轉稜鏡控制中心波長及帶寬。除此之外,該帶寬控制系統使用串接操作的兩稜鏡是非常困難的。Variable amplification of a beam incident on a central wavelength selective optical element (e.g., a dispersion grating) may also affect the bandwidth of the source. This system is discussed in U.S. Patent No. 6,393,037 (issued to Basting et al. on May 21, 2002), the content of which is hereby incorporated by reference. Basting's abstract describes a tunable laser comprising an angularly dispersive optical element (grating) and one or two included in a line narrowing module Rotate the beam expander to adjust the bandwidth. The complex 稜鏡 beam expanders (when both are used) are exposed to be mechanically connected to each other, so that when the magnification changes, the incident angle of the light beam on the dispersing element is not changed. This configuration makes it very difficult, if not impossible, to control the center wavelength and bandwidth with the rotation 稜鏡. In addition to this, it is very difficult for the bandwidth control system to use two twists of the serial operation.
相信GigaPhoton發佈了一種使用某種光學致動執行E95 控制的產品。日本發佈的專利申請案2006024855(於2004年7月9日發佈)也揭露了一種可變放大LNM,具有兩個旋轉稜鏡且將在一種源雷射與放大雷射之間的一差動放電發射時序用於帶寬控制。此一配置使其難以(若不是不可能的)使用稜鏡控制中心波長及帶寬,以及在此一系統內利用dtMOPA控制帶寬可能具有一些缺點。It is believed that GigaPhoton has released a product that uses some kind of optical actuation to perform E 95 control. Japanese Patent Application No. 2006024855 (issued on July 9, 2004) also discloses a variable-amplitude LNM with two rotating turns and a differential discharge between a source laser and an amplified laser. The transmission timing is used for bandwidth control. This configuration makes it difficult, if not impossible, to use the control center wavelength and bandwidth, and the use of dtMOPA to control the bandwidth within such a system may have some disadvantages.
第12圖(取自’037申請案)描述了使用△tMOPA 的E95 帶寬控制中心。使用差動發射時間作為一細致動器控制E95 帶寬具有一些優點,包括:(1)E95 之測量及△tMOPA 之變化都可能以大約幾十個脈衝時標或者更短發生,例如脈衝對脈衝,從而允許非常高的頻率干擾拒絕;以及(2)致動之可用範圍足夠大以衰減/抑制被作為目標的帶寬偏移之來源,即雷射能量及工作週期變化之較高的頻率影響。Figure 12 (taken from the '037 application) describes the use of E 95 bandwidth control center of △ t MOPA. Using the differential transmit time as a fine actuator to control the E 95 bandwidth has several advantages, including: (1) E 95 measurements and Δt MOPA changes can occur with approximately tens of pulse time stamps or shorter, such as pulses For pulses, allowing very high frequency interference rejection; and (2) the available range of actuation is large enough to attenuate/suppress the source of the target's bandwidth offset, ie the higher frequency of laser energy and duty cycle variation influences.
現存類型的主動帶寬控制可能具有一些缺點,例如用太長時間從一大的干擾(例如,在一氟注入之後的一暫態)或目標帶寬之變化恢復。其等可能使帶寬離開目標多達5fm(當考慮一55個擊發移動平均值之例子)或者6 fm(當 考慮一55個擊發標準偏差之例子,以積分求和)。返回到目標可能花費多於幾十秒。Existing types of active bandwidth control may have some drawbacks, such as recovering from a large amount of interference (eg, a transient after a fluorine injection) or a change in target bandwidth for too long. It may cause the bandwidth to leave the target as much as possible 5fm (when considering a 55-shot moving average) or 6 fm (when considering an example of a 55 standard deviation of firing, sum in points). It may take more than a few tens of seconds to return to the target.
除此之外,特別是以低工作週期,一目標變化(例如,從300 fm至400)可能太慢,即用長達大約20秒,或者從400 fm到低至290fm用長達大約30秒,當要求可能低至大約10秒時。In addition to this, especially at low duty cycles, a target change (for example, from 300 fm to 400) may be too slow, ie up to about 20 seconds, or from 400 fm to as low as 290 fm for up to about 30 seconds. When the requirement may be as low as about 10 seconds.
對於其他方面,誤差可能由於控制信號之濾波而產生(例如,在一控制器步進信號可被發給一帶寬致動步進器之前延遲太多脈衝),使得在帶寬可以較低頻率被取樣之低工作週期上,具有非常高的機率在一叢發期間步進命令將不發生。因為步進器命令或步進器本身可在一叢發中間間隔期間被致能,所以帶寬內的叢發對叢發誤差可在彼此上建立,和沒有任何修正信號被發給(複數)帶寬控制致動器。For other aspects, the error may be due to filtering of the control signal (eg, delaying too many pulses before a controller stepped signal can be sent to a bandwidth actuated stepper) so that the bandwidth can be sampled at a lower frequency On low duty cycles, there is a very high probability that stepping commands will not occur during a burst. Since the stepper command or the stepper itself can be enabled during a burst interval, bursts within the bandwidth can be established on each other and no correction signal is sent to the (complex) bandwidth. Control the actuator.
習知的帶寬穩定控制能夠以一設定且忘記方式設定一帶寬控制設定點。較嚴格的要求需要一可調諧帶寬設定可由雷射光源之終端使用者控制。也要求帶寬控制系統沒有對其他雷射操作或輸出參數之控制產生負面影響,例如輸出脈衝能量及劑量穩定及類似者。Conventional bandwidth stabilization control can set a bandwidth control set point in a set and forgotten manner. The more stringent requirements require a tunable bandwidth setting that can be controlled by the end user of the laser source. Bandwidth control systems are also required to have no negative impact on other laser operations or control of output parameters, such as output pulse energy and dose stabilization and the like.
本文提出的使用雷射共振腔外部的一可變孔徑及結合其他帶寬控制致動器的主動帶寬控制相對於習知技術具有優勢。該共振腔內的光學元件可被簡化及減少數量,特別是在一個單一腔室內或者在光學負載非常嚴重的一多變化雷射系統之放大器內。該可變孔徑結合其他致動器可以是一用於帶寬控制的粗調整器或細調整器。The use of a variable aperture outside the laser cavity and active bandwidth control in conjunction with other bandwidth controlled actuators as proposed herein has advantages over prior art techniques. The optical components within the resonant cavity can be simplified and reduced in number, particularly in a single chamber or in an amplifier of a multi-variable laser system where the optical load is very severe. The variable aperture in combination with other actuators can be a coarse adjuster or a fine adjuster for bandwidth control.
本發明提供一種用於控制一雷射系統內的帶寬之方法,該雷射系統包含:一氣體放電種源雷射,具有一共振腔且產生一種源雷射輸出;一氣體放電放大器雷射,放大該種源雷射輸出且產生一雷射系統輸出;一帶寬度量單元,測量該雷射系統輸出之帶寬且提供一帶寬測量值;以及一帶寬誤差信號產生器,接收該帶寬測量值及一帶寬設定點且提供一帶寬誤差信號;一可變放大譜線窄化單元,位於該種源雷射之共振腔內,包含一光柵及一可變光束放大光學系統;一差動時序控制器,選擇該種源雷射內的一個別電極對與該放大器雷射內的一個別電極對之間的一放電之發射的時序;該方法包含以下步驟:利用一帶寬控制器控制帶寬,該帶寬控制器具有三個模式的放大控制,其中一第一模式不控制該譜線窄化單元內的光束之放大,一第二模式將該譜線窄化單元內的該光束之該放大驅動至獨立於該帶寬誤差信號的一選定值,以及一第三模式根據該帶寬誤差信號驅動該譜線窄化單元內的該光束之該放大;以及 其中在每個模式內,該差動時序控制器根據該帶寬誤差信號選擇該時序或者不考慮該帶寬誤差信號。The present invention provides a method for controlling a bandwidth within a laser system, the laser system comprising: a gas discharge source laser having a resonant cavity and producing a source laser output; a gas discharge amplifier laser, Amplifying the source laser output and generating a laser system output; a bandwidth metric unit measuring a bandwidth of the laser system output and providing a bandwidth measurement value; and a bandwidth error signal generator receiving the bandwidth measurement value and a a bandwidth setting point and providing a bandwidth error signal; a variable amplification line narrowing unit, located in the resonant cavity of the source laser, comprising a grating and a variable beam amplifying optical system; a differential timing controller, Selecting a timing of a discharge between a pair of electrodes within the source laser and a pair of electrodes within the laser of the amplifier; the method comprising the steps of: controlling bandwidth using a bandwidth controller, the bandwidth control The device has three modes of amplification control, wherein a first mode does not control the amplification of the beam in the line narrowing unit, and a second mode narrows the line Of the beam to drive the amplified error signal independent of the bandwidth of a selected value, and a third mode according to the bandwidth of the amplified error signal drives the light within the narrow spectral line unit; and Wherein in each mode, the differential timing controller selects the timing based on the bandwidth error signal or does not consider the bandwidth error signal.
本發明提供一種雷射系統,包含:一氣體放電種源雷射,具有一共振腔且產生一種源雷射輸出;一氣體放電放大器雷射,放大該種源雷射輸出且產生一雷射系統輸出;一帶寬度量單元,測量該雷射系統輸出之帶寬且提供一帶寬測量值;以及一帶寬誤差信號產生器,接收該帶寬測量值及一帶寬設定點且提供一帶寬誤差信號;一可變放大譜線窄化單元,位於該種源雷射之共振腔內,包含一光柵及一可變光束放大光學系統;一差動時序控制器,選擇該種源雷射內的一個別電極對與該放大器雷射內的一個別電極對之間的一放電之發射的時序;一帶寬控制器具有三個模式的放大控制,該帶寬控制器不控制該可變放大譜線窄化單元的一第一模式,該帶寬控制器控制該可變放大譜線窄化單元以將該放大驅動至一與帶寬誤差信號無關的選定值的一第二模式,以及該帶寬控制器根據該帶寬誤差信號控制該可變放大譜線窄化單元以選擇該雷射系統輸出之該帶寬的一第三模式;以及其中該差動時序控制器根據該帶寬誤差信號選擇該時序或者不考慮該帶寬誤差信號。The invention provides a laser system comprising: a gas discharge seed source laser having a resonant cavity and generating a source laser output; a gas discharge amplifier laser, amplifying the source laser output and generating a laser system An output metric unit that measures a bandwidth of the output of the laser system and provides a bandwidth measurement value; and a bandwidth error signal generator that receives the bandwidth measurement value and a bandwidth set point and provides a bandwidth error signal; a magnifying line narrowing unit, located in the resonant cavity of the source laser, comprising a grating and a variable beam amplifying optical system; a differential timing controller for selecting a pair of electrodes in the source laser a timing of a discharge emission between a pair of electrodes within the laser of the amplifier; a bandwidth controller having three modes of amplification control, the bandwidth controller not controlling a first of the variable amplification line narrowing unit a mode, the bandwidth controller controlling the variable amplification line narrowing unit to drive the amplification to a second mode of a selected value independent of the bandwidth error signal, and the The wide controller controls the variable amplification line narrowing unit to select a third mode of the bandwidth of the laser system output according to the bandwidth error signal; and wherein the differential timing controller selects the timing according to the bandwidth error signal Or the bandwidth error signal is not considered.
本發明提供一種雷射系統,包含:一雷射光源,包含:一種源雷射,定義一產生一輸出的光學共振腔;一放大器雷射,接收該種源雷射輸出且放大該種源雷射輸出;一帶寬度量模組,測量由該光源產生的一雷射輸出光脈衝束脈衝之帶寬且產生一帶寬測量值;一帶寬誤差信號產生器,接收該帶寬測量值及一帶寬設定點且提供一帶寬誤差信號;一帶寬選擇元件,位於該種源雷射之該共振腔外部,選擇光束之一空間部分以選擇性地改變該種源雷射輸出之該帶寬。The invention provides a laser system comprising: a laser light source comprising: a source laser defining an optical resonant cavity for generating an output; an amplifier laser receiving the laser output of the source and amplifying the source lightning a bandwidth measurement module that measures a bandwidth of a laser output light pulse pulse generated by the light source and generates a bandwidth measurement value; a bandwidth error signal generator receives the bandwidth measurement value and a bandwidth set point and A bandwidth error signal is provided; a bandwidth selecting component located outside the resonant cavity of the source laser, and a spatial portion of the beam is selected to selectively vary the bandwidth of the source laser output.
本發明提供一種雷射系統,包含:一種源雷射,定義一產生一輸出的光學共振腔;一放大器雷射,接收且放大該種源雷射之該輸出且提供一雷射系統輸出;一帶寬度量模組,測量由該光源產生的一雷射輸出光脈衝束脈衝之帶寬且產生一帶寬測量值;一帶寬誤差信號產生器,接收該帶寬測量值及一帶寬設定點且提供一帶寬誤差信號;一差動時序系統,回應該帶寬誤差信號以選擇性地調整該種源雷射與放大器之間的一差動發射時間;以及一光束大小(dimension)調整系統,可控地調整在該種源雷射之該共振腔內的一光束之一光束大小以選擇性地改 變該種源雷射輸出之帶寬且也可控地調整該種源脈衝之中心波長;以及該光束大小調整系統包含:多數個光束大小調整稜鏡;以及至少另一稜鏡,包含一中心波長選擇稜鏡。The present invention provides a laser system comprising: a source laser defining an optical resonant cavity that produces an output; an amplifier laser that receives and amplifies the output of the source laser and provides a laser system output; a bandwidth metric module for measuring a bandwidth of a laser output optical pulse beam generated by the light source and generating a bandwidth measurement value; a bandwidth error signal generator receiving the bandwidth measurement value and a bandwidth set point and providing a bandwidth error a differential timing system that echoes a bandwidth error signal to selectively adjust a differential transmission time between the source laser and the amplifier; and a beam adjustment system that is controllably adjusted The beam size of one of the beams in the resonant cavity of the source laser is selectively modified Varying the bandwidth of the source laser output and also controllably adjusting the center wavelength of the source pulse; and the beam size adjustment system includes: a plurality of beam size adjustments; and at least one other wavelength, including a center wavelength Choose 稜鏡.
本發明提供一種裝置,包含:一種源雷射,定義一產生一輸出的光學共振腔;一放大器雷射,接收且放大該種源雷射之該輸出且提供一雷射系統輸出;一帶寬度量模組,測量由該光源產生的一雷射輸出光脈衝束脈衝之帶寬且產生一帶寬測量值;一帶寬誤差信號產生器,接收該帶寬測量值及一帶寬設定點且提供一帶寬誤差信號;一差動時序系統,回應該帶寬誤差信號以選擇性地調整該種源雷射與放大器之間的一差動發射時間;以及一光束大小調整系統,可控地調整該種源雷射之該共振腔內的一光束之一光束大小以選擇性地改變該種源雷射輸出之帶寬且也可控地調整該種源脈衝之中心波長;以及該光束大小調整系統包含:多數個光束大小調整稜鏡;一分散光學元件;以及一中心波長選擇稜鏡,至少部分定義該分散光學元件上的該光束之一入射角;以及 一中心波長選擇反射鏡,與該至少另一稜鏡協作,定義該分散光學元件上的該光束之該入射角。The present invention provides an apparatus comprising: a source laser defining an optical resonant cavity that produces an output; an amplifier laser that receives and amplifies the output of the source laser and provides a laser system output; a bandwidth metric a module that measures a bandwidth of a laser output optical pulse beam pulse generated by the light source and generates a bandwidth measurement value; a bandwidth error signal generator receives the bandwidth measurement value and a bandwidth set point and provides a bandwidth error signal; a differential timing system that echoes a bandwidth error signal to selectively adjust a differential transmission time between the source laser and the amplifier; and a beam size adjustment system that controllably adjusts the source laser a beam size of a beam within the cavity to selectively vary the bandwidth of the source laser output and controllably adjust the center wavelength of the source pulse; and the beam size adjustment system includes: a plurality of beam size adjustments a dispersive optical element; and a center wavelength selective 稜鏡 at least partially defining an incident angle of the light beam on the dispersive optical element; A center wavelength selective mirror, in cooperation with the at least one other, defines the angle of incidence of the beam on the dispersive optical element.
第1圖顯示了一帶寬控制設備E95 敏感度曲線;第2圖描述了依據被揭露的標的之一實施例之層面的干擾類型與時標及幅值;第3圖示意性且以方塊圖形式顯示了依據被揭露的標的之一實施例之層面的具有一可變放大譜線窄化模組及差動發射時間(dtMOPA)帶寬控制的一多級氣體放電雷射系統;第4圖示意性且以方塊圖形式顯示了依據被揭露的標的之一實施例之層面的具有4個稜鏡及一光柵的一實施例,其中至少一稜鏡可被旋轉以增加/減少光束寬度,從而改變帶寬;第5圖描述了可用於被揭露的標的之一實施例之層面的一雷射控制系統整體架構;第6圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面控制的一代表性雷射系統“植入”;第7圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的一帶寬控制器;第8圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的一擊發平滑器;第9圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的一不感帶磁滯方塊;第10圖示意性且以方塊圖形式描述了依據被揭露的標 的之一實施例之層面的一控制模式選擇器;第11圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的具有複數稜鏡及一中心波長選擇反射鏡的一實施例;第12圖描述了一使用△tMOPA 的E95 帶寬控制中心;第13圖示意性地描述了依據被揭露的標的之一實施例之層面的一可變放大LNM;第14圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的一可調整孔徑帶寬控制致動器(控制中心);第15圖示意性地且以方塊圖形式顯示了依據被揭露的標的之一實施例之層面的一帶寬控制系統;以及第16圖示意與光束經過的孔徑之大小相依的帶寬變化之例子。Figure 1 shows a bandwidth control device E 95 sensitivity curve; Figure 2 depicts the interference type and time scale and amplitude of the layer according to one embodiment of the disclosed subject matter; Figure 3 is schematic and block The diagram shows a multi-stage gas discharge laser system with a variable amplification line narrowing module and differential emission time (dtMOPA) bandwidth control in accordance with one embodiment of the disclosed subject matter; Figure 4 Illustratively and in block diagram form an embodiment having four turns and a grating in accordance with a layer of one embodiment of the disclosed subject matter, wherein at least one turn can be rotated to increase/decrease the beam width, Thereby changing the bandwidth; Figure 5 depicts the overall architecture of a laser control system that can be used at the level of one of the disclosed embodiments; Figure 6 is a schematic and block diagram depicting one of the disclosed targets A representative laser system of the embodiment controls "implantation"; Figure 7 schematically and in block diagram form a bandwidth controller in accordance with one aspect of the disclosed embodiment; Figure 8 Schematic and block diagram The form describes a firing smoother in accordance with the level of one embodiment of the disclosed subject matter; FIG. 9 is a schematic and block diagram depicting a non-inductive hysteresis in accordance with the level of one embodiment of the disclosed subject matter. Figure 10 is a schematic and block diagram depicting a control mode selector in accordance with the level of one embodiment of the disclosed subject matter; Figure 11 is schematically and in block diagram depicting the disclosure according to the disclosure Example of a level having a plurality of Example Prism and a central wavelength selective mirror subject to one embodiment; FIG. 12 E 95 describes the use of a bandwidth control center of △ t MOPA; FIG. 13 schematically depicts the A variable amplification LNM in accordance with a level of one embodiment of the disclosed subject matter; FIG. 14 schematically and in block diagram form an adjustable aperture bandwidth control in accordance with a level of an embodiment of the disclosed subject matter Actuator (control center); Figure 15 shows schematically and in block diagram form a bandwidth control system in accordance with the level of one of the disclosed embodiments; and Figure 16 illustrates the aperture through which the beam passes. size Examples of changes in accordance with the bandwidth of.
依據被揭露的標的之一實施例之層面的主動帶寬控制之主要目的是控制雷射光之E95 帶寬,使用與先前被使用的主動帶寬控制系統相同或類似的(複數)輸入信號,然而具有不同的信號處理及致動機制。因此,一可調諧進階帶寬穩定“ABS”(“T-ABS”)被提出以將帶寬控制到某目標設定點,該目標設定點可由一雷射終端使用者或者一雷射光使用工具控制系統選擇。The primary purpose of active bandwidth control at the level of one of the disclosed embodiments is to control the E 95 bandwidth of the laser, using the same or similar (complex) input signals as the previously used active bandwidth control system, but with different Signal processing and actuation mechanisms. Therefore, a tunable advanced bandwidth stabilization "ABS"("T-ABS") is proposed to control the bandwidth to a target set point that can be used by a laser end user or a laser light using a tool control system select.
將帶寬控制到±50 fm或更少(對於常數脈衝接收速率或其他選定的常數操作參數)被提出且在大於50 fm之帶寬 內具有一誤差,該系統能夠以大於或等於0.0003fm/雷射擊發返回到設定點。中心波長沒有被影響或者受到最小的影響,同時帶寬之控制在除了一目標變化模式之外的模式(透過<5 fm-考慮一55擊發移動平均波長值為例-以及<6 fm-考慮一55擊發移動標準差為例,其以積分求和)。一控制演算法可使用各種帶寬致動器控制步進器以用於帶寬選擇(粗及或細),包括一可變放大譜線窄化模組(“VMLNM”)、一帶寬控制模組(“BWCM”)、一光束分析模組(“BAM”),如本文所討論的。Control bandwidth to ±50 fm or less (for constant pulse reception rate or other selected constant operating parameters) is proposed and is greater than 50 fm bandwidth With an error inside, the system is capable of returning to the set point with a firing rate greater than or equal to 0.0003 fm/ray. The center wavelength is not affected or minimally affected, while the bandwidth is controlled in a mode other than a target change mode (through <5 fm - consider a 55 shot moving average wavelength value - and <6 fm - consider a 55 For example, the firing standard deviation is summed by the integral). A control algorithm can use various bandwidth actuators to control the stepper for bandwidth selection (thick and thin), including a variable amplification line narrowing module ("VMLNM"), a bandwidth control module ( "BWCM"), a beam analysis module ("BAM"), as discussed herein.
一被量測的E95 信號被用以決定一帶寬控制設備(“BCD”)或類似者之調整。包括用於使中心波長選擇光柵變形從而影響雷射光源的輸出之帶寬的機制之BCD是該項領域內眾所周知的。帶寬控制可以如下目標實現:保持在一BCD操作曲線之一特定側,例如BCD曲線之右側或左側,如第1圖中所描述的。A measured E 95 signal is used to determine the adjustment of a Bandwidth Control Device ("BCD") or the like. BCDs that include mechanisms for deforming the central wavelength selective grating to affect the bandwidth of the output of the laser source are well known in the art. Bandwidth control can be achieved by maintaining a particular side of a BCD operating curve, such as to the right or left of the BCD curve, as depicted in Figure 1.
申請人已注意到,干擾80可由影響此等雷射操作參數(例如,E95 帶寬)的時標及/或幅值被分類,如第2圖之圖表所描述的,且如序列號為11/510037的美國專利申請案(名稱為“ACTIVE SPECTRAL CONTROL OF DUV LIGHT SOURCE”,於2006年8月25日提出申請,於2007年8月23日發佈,公開號為US-2007-0195836-A1)中較詳細解釋的,此申請案以參照方式被併入本文。如此處所解釋的,在一細致動範圍82(例如,能量變化或較高頻率工作週期影響)或粗致動範圍84(例如,較低頻率工作週期影響,氣體老化或元 件老化/誤對準)內的此等干擾80可由帶寬控制致動器(粗致動或細致動或其二者一起)產生。Applicants have noted that the interference 80 can be classified by the time scale and/or amplitude affecting these laser operating parameters (e.g., E 95 bandwidth), as depicted in the graph of Figure 2, and if the serial number is 11 US Patent Application No. 5,510,037, entitled "ACTIVE SPECTRAL CONTROL OF DUV LIGHT SOURCE", filed on August 25, 2006, issued on August 23, 2007, publication number US-2007-0195836-A1 As explained in greater detail, this application is incorporated herein by reference. As explained herein, a fine actuation range 82 (eg, energy change or higher frequency duty cycle effect) or coarse actuation range 84 (eg, lower frequency duty cycle effects, gas aging or component aging/misalignment) Such interferences 80 within can be generated by a bandwidth controlled actuator (coarse actuation or fine actuation or both).
第3圖顯示了具有一可變放大譜線窄化模組及差動發射時間(dtMOPA)帶寬控制的一多級氣體放電雷射500。第一級可以是一主振盪器MO,以及下一級可以是一單通道功率放大器、一多通道功率放大器、一功率振盪器或一行波放大器(例如,一功率環放大器),其中振盪在作為一放大級的共振腔內發生。Figure 3 shows a multi-stage gas discharge laser 500 with a variable amplification line narrowing module and differential emission time (dtMOPA) bandwidth control. The first stage may be a main oscillator MO, and the next stage may be a single channel power amplifier, a multi-channel power amplifier, a power oscillator or a row-wave amplifier (for example, a power loop amplifier), wherein the oscillation is as a Occurs in the cavity of the amplification stage.
此一雷射系統之一例子可包括第3圖中所示的元件中的一些或所有,取決於配置。第3圖中所示的元件包括一可變放大譜線窄化模組502、一第一級腔室504、一第一級輸出耦接器506、轉向光學元件508a,b、一輸入耦接器510、一第二級腔室512、一分束器514、一帶寬測量模組516以及一放電時序控制模組518。該種源雷射504可以是一氣體放電準分子或者氟分子雷射,例如一XCl、XF、KrF、ArF、F2或類似的雷射。此等類型的雷射已知用於晶圓之光刻製程處理以製造半導體電路。該種源雷射504可(例如)在該譜線窄化模組502與該輸出耦接器506之間定義一光學共振腔且產生一輸出。該放大器雷射512可透過中繼光學元件(反射鏡508a及b)接收種源雷射輸出且放大該種源雷射輸出以產生一雷射系統輸出。該帶寬度量模組516(為該項領域內眾所周知)可測量一雷射輸出之帶寬且可提供可被一帶寬控制器518(如以下所討論的)使用的一帶寬測量值,該帶寬控制器518可以是個別的單元以產生可與一目標/設定點比較 的帶寬誤差。差動時序可根據該誤差信號被調整以調整雷射系統輸出帶寬。An example of such a laser system may include some or all of the elements shown in Figure 3, depending on the configuration. The component shown in FIG. 3 includes a variable amplification line narrowing module 502, a first stage chamber 504, a first stage output coupler 506, steering optical elements 508a, b, and an input coupling. The device 510, a second stage chamber 512, a beam splitter 514, a bandwidth measuring module 516 and a discharge timing control module 518. The source laser 504 can be a gas discharge excimer or a fluorine molecular laser, such as an XCl, XF, KrF, ArF, F2 or similar laser. These types of lasers are known for lithography process processing of wafers to fabricate semiconductor circuits. The source laser 504 can define, for example, an optical resonant cavity between the line narrowing module 502 and the output coupler 506 and produce an output. The amplifier laser 512 can receive a source laser output through the relay optics (mirrors 508a and b) and amplify the source laser output to produce a laser system output. The bandwidth metric module 516 (known in the art) can measure the bandwidth of a laser output and can provide a bandwidth measurement that can be used by a bandwidth controller 518 (as discussed below). 518 can be individual units to produce a comparable to a target/set point Bandwidth error. The differential timing can be adjusted based on the error signal to adjust the laser system output bandwidth.
第4圖顯示了具有4個稜鏡520、522、524、526以及一光柵528的一帶寬(及中心波長)致動器機制(控制中心)之一可能的實施例。稜鏡520可被固定在一包括旋轉移動固定(例如,一彎曲固定(圖未示))的致動器(圖未示)上,因此該稜鏡520可透過一旋轉致動器(例如,一步進器馬達(圖未示)及/或PZT(圖未示))旋轉以增加/減少光束寬度,從而改變帶寬。稜鏡522可保持靜止或者也可具有一旋轉位置致動器(圖未示)。稜鏡524也被固定以旋轉移動(如對稜鏡520所描述的)(例如)以細調整中心波長(例如,以飛米(10-15 m)之等級變化)。稜鏡524也可被如此固定以粗調整中心波長(例如,以10×10-15 m之等級變化)。Figure 4 shows one possible embodiment of a bandwidth (and center wavelength) actuator mechanism (control center) having four turns 520, 522, 524, 526 and a grating 528. The crucible 520 can be fixed to an actuator (not shown) including a rotationally fixed (eg, a curved fixation (not shown)) such that the crucible 520 can be transmitted through a rotary actuator (eg, A stepper motor (not shown) and/or PZT (not shown) rotates to increase/decrease the beam width, thereby changing the bandwidth. The crucible 522 can remain stationary or can have a rotational position actuator (not shown). The crucible 524 is also fixed for rotational movement (as described for 520) (for example) to fine tune the center wavelength (eg, in the order of femto ( 10-15 m)). The crucible 524 can also be fixed in such a way as to coarsely adjust the center wavelength (e.g., on a scale of 10 x 10 -15 m).
第11圖示意性地描述了一帶寬(及中心波長)致動器(控制中心)之一可能的實施例,其中此一RMAX 反射鏡540及其致動器540a(為雷射系統中心波長選擇之領域內眾所周知的)可被用以將自該光束擴展稜鏡526出來的被擴展光束折射回到一光柵528。該光柵528可以是一延長光柵以使用被擴展的光束,例如一被擴展45X的光束。藉由決定該光柵528上的光束之入射角,該反射鏡540可被部分用於中心波長控制。該項領域內所知的RMAX 折疊式反射鏡本身可具有對一個單一光學元件之粗及細中心波長控制,即將一步進器馬達(圖未示)用於粗控制及將一PZT堆疊(圖未示)用於細且快中心波長控制,如以上所注明的。當結合一中心波長控制 稜鏡(例如稜鏡520)時,該RMAX 反射鏡540可保持其相對於該光柵528之角度的控制或者只使用PZT堆疊之細控制且不使用任何步進器馬達控制。該中心波長控制稜鏡(例如,稜鏡520)可被用於粗控制,接著該RMAX 折疊式反射鏡540可被用於較細的中心波長控制,或者反之亦然。Figure 11 schematically depicts one possible embodiment of a bandwidth (and center wavelength) actuator (control center), wherein the R MAX mirror 540 and its actuator 540a (which is the center of the laser system) As is well known in the art of wavelength selection, it can be used to refract the extended beam from the beam extension 526 back to a grating 528. The grating 528 can be an elongated grating to use an expanded beam, such as a beam that is extended by 45X. By determining the angle of incidence of the beam on the grating 528, the mirror 540 can be used in part for center wavelength control. The R MAX folding mirrors known in the art can have coarse and fine center wavelength control for a single optical component, ie, a stepper motor (not shown) for coarse control and a PZT stack (Fig. Not shown) for fine and fast center wavelength control, as noted above. When combined with a central wavelength control 稜鏡 (e.g., 稜鏡 520), the R MAX mirror 540 can maintain its control relative to the angle of the grating 528 or use only fine control of the PZT stack without using any stepper motor control. The center wavelength control 稜鏡 (eg, 稜鏡 520) can be used for coarse control, and then the R MAX folding mirror 540 can be used for finer center wavelength control, or vice versa.
在後一實施例中,該PZT堆疊可被刪除,且僅一步進器馬達被用以定位該RMAX 折疊式反射鏡以供粗中心波長控制,同時該中心波長控制稜鏡可被用於較細的中心波長選擇。可選擇的方式是,設於該光束擴展機制內的一連串稜鏡內的每個稜鏡可具有一類似RMAX 的粗控制及細控制,其中一步進器馬達用於粗調整以及一PZT堆疊用於細調整,或者該粗調整稜鏡可利用一步進器馬達或類似的機械調整被控制,且該(等)細調整稜鏡藉由一較快且較細的控制致動器被控制(例如一PZT堆疊)。In the latter embodiment, the PZT stack can be deleted, and only one stepper motor is used to position the RMAX folding mirror for coarse center wavelength control, while the center wavelength control can be used for comparison. Fine center wavelength selection. Alternatively, each of the series of turns provided in the beam expansion mechanism may have a rough control and fine control similar to R MAX , wherein a stepper motor is used for coarse adjustment and for a PZT stack. For fine adjustment, or the coarse adjustment can be controlled using a stepper motor or similar mechanical adjustment, and the fine adjustment is controlled by a faster and thinner control actuator (eg A PZT stack).
信號可自雷射硬體被接收以指出來自最近雷射光之E95 帶寬的測量值。一控制器(如第7圖中所示)或者元件502及/或518之部分接著可透過各種濾波、不感帶(deadbands)、磁滯及平滑化處理該等信號且產生以一(複數)命令之形式的一(複數)輸出給可執行如(舉例而言)移動或扭曲一(複數)機械及/或光學元件此類的功能之一(複數)致動器。此(等)元件之移動或扭曲可引起E95 帶寬之變化以減少帶寬錯誤。The signal can be received from the laser hardware to indicate a measurement from the E 95 bandwidth of the most recent laser light. A controller (as shown in FIG. 7) or portions of components 502 and/or 518 can then process the signals through various filtering, deadbands, hysteresis, and smoothing and generate a (plural) command. One (plural) output of the form is one of the functions (plural) actuators that perform such functions as, for example, moving or distorting a (plural) mechanical and/or optical component. This movement or distortion (and other) components can cause a change of the bandwidth of the E 95 to reduce the bandwidth errors.
可具有幾種控制模式,例如下列但不限於下列,其中沒有任何放大控制被實施(即,可變放大LNM變化系統沒有被使用),因此沒有由於可變放大產生對帶寬控制之影響。 在此模式中,可具有兩個子模式,在一模式中,dtMOPA雷射時序沒有被用於直接控制帶寬,以及在一模式中,dtMOPA被用以直接控制帶寬。There may be several control modes, such as the following but not limited to the following, in which no amplification control is implemented (i.e., the variable amplification LNM variation system is not used), and thus there is no effect on bandwidth control due to variable amplification. In this mode, there can be two sub-modes, in one mode, the dtMOPA laser timing is not used to directly control the bandwidth, and in one mode, dtMOPA is used to directly control the bandwidth.
在一第二放大驅動模式中,可變放大也未被使用,雖然該系統將可變放大驅動至某選定的值(例如,至一最大值,例如至45X)。在此第二可變放大模式中,對於一第一dtMOPA時序模式,能量及時序控制演算法設定dtMOPA,且dtMOPA或可變放大(除了被驅動至一選定值,例如全45X放大之外)都沒有被改變以供帶寬控制。對一第二dtMOPA時序控制模式,帶寬利用dtMOPA被設定,同時放大被維持在(例如)45X放大。In a second amplified drive mode, variable amplification is also unused, although the system drives the variable amplification to a selected value (e.g., to a maximum value, e.g., to 45X). In this second variable amplification mode, for a first dtMOPA timing mode, the energy and timing control algorithm sets dtMOPA, and dtMOPA or variable amplification (except for being driven to a selected value, such as full 45X amplification) Not changed for bandwidth control. For a second dtMOPA timing control mode, the bandwidth is set using dtMOPA while the amplification is maintained at, for example, 45X amplification.
另一放大控制模式可被使用,其中放大基於一些帶寬回饋控制帶寬。接著放大倍率可基於帶寬之一目標被選擇,如以上所注明的。在一第一dtMOPA控制模式之放大控制之此模式中,該能量及時序控制演算法出於除了帶寬控制之外的其他原因設定dtMOPA時序,例如雷射效率、劑量穩定或類似者。放大倍率被選擇以獲得獨立於dtMOPA的一選定的帶寬。在一第二dtMOPA控制模式中,VMLNM之放大倍率及dtMOPA都可被選擇以獲得一目標帶寬,其中一者被用作一粗帶寬選擇機制且另一者被用作一細選擇機制。Another amplification control mode can be used, where amplification is based on some bandwidth feedback control bandwidth. The magnification can then be selected based on one of the bandwidth targets, as noted above. In this mode of amplification control of a first dtMOPA control mode, the energy and timing control algorithm sets dtMOPA timing for reasons other than bandwidth control, such as laser efficiency, dose stabilization, or the like. The magnification is selected to obtain a selected bandwidth that is independent of dtMOPA. In a second dtMOPA control mode, both the magnification of the VMLNM and the dtMOPA can be selected to achieve a target bandwidth, one of which is used as a coarse bandwidth selection mechanism and the other as a fine selection mechanism.
該系統可被設定使得具有磁滯配置的一不感帶(deadband)被使用,從而(舉例而言)控制只在誤差(絕對值)離開一較大/外不感帶時啟動以及在誤差返回到一較小/內不感帶時關閉。而且,帶寬馬達抖動可被使用,例如利用 一下限制值,在改變方向之前在一方向內的微步之數目的一下限制值。除了利用一帶寬目標變化之外,該系統可被配置以獲得在一給定工作週期(例如,對於(舉例而言)100個叢發長度,以5%DC為10秒)之某時間限制值內的新目標,同時光刻之光源的使用被禁能。這可限制抖動及/或客製化帶寬控制以指定客戶要求。The system can be set such that a deadband with a hysteresis configuration is used, such that, for example, control only initiates when the error (absolute value) leaves a large/outer sense zone and returns to the error Closed when the smaller/inner is not sensed. Moreover, bandwidth motor jitter can be used, for example, The limit value, the lower limit of the number of microsteps in one direction before changing direction. In addition to utilizing a bandwidth target change, the system can be configured to obtain a time limit value for a given duty cycle (eg, for example, 100 burst lengths, 5% DC for 10 seconds) The new target within, while the use of lithographic light sources is disabled. This can limit jitter and/or custom bandwidth control to specify customer requirements.
當被濾波的帶寬在不感帶之外時,該控制器可只在一方向內命令該步進器,從而在不感帶邊界附近阻止與操作有關的抖動。若帶寬(誤差信號)大於高/外不感帶值,則此控制致能帶寬控制致動器回饋位置/初始化命令發出,以及若帶寬(誤差信號)小於低/內不感帶值,則禁能命令發出。否則,系統不改變目前的命令發出狀態(致能或禁能),同時該帶寬(誤差信號)在高/外不感帶值與低/內不感帶值中間。換言之,當該帶寬(誤差)信號在該等不感帶限制值中間時(已從一高值進入此區域),以致輸入命令發出被致能,於是其保持被致能直到該帶寬(誤差)信號經過低/內不感帶值且命令發出被禁能。類似地,當來自小於低/內不感帶值(其中命令發出被禁能)時,此功能保持被禁能直到帶寬(誤差)信號經過高/外不感帶值。When the filtered bandwidth is out of band, the controller can command the stepper in only one direction to prevent operational-related jitter near the band boundary. If the bandwidth (error signal) is greater than the high/outer sense band value, then the control enables the bandwidth control actuator feedback position/initialization command to be issued, and if the bandwidth (error signal) is less than the low/inner sense band value, the disable command is issued. issue. Otherwise, the system does not change the current command issue state (enabled or disabled), and the bandwidth (error signal) is intermediate between the high/outer sensed value and the low/inner sensed value. In other words, when the bandwidth (error) signal is in the middle of the non-inductive band limit value (has entered the region from a high value), so that the input command is issued, so that it remains enabled until the bandwidth (error) signal After the low/inner is not sensed, the command is issued and disabled. Similarly, when the value from less than the low/inner sense band (where the command is issued is disabled), this function remains disabled until the bandwidth (error) signal passes the high/outer sense band value.
不感帶之大小可被選擇以取捨幾個效能值,例如減少抖動、控制器回應時間對干擾之總速度以及被允許的帶寬誤差之大小。The size of the insensitive band can be chosen to choose between several performance values, such as reduced jitter, controller response time versus total speed of interference, and the amount of bandwidth error allowed.
該系統可使用一函數產生器(可使用一豐富特徵集合)以(僅舉例)命令一帶寬控制致動器(例如一步進器馬達)至 擊發數之任意函數。The system can use a function generator (a rich set of features can be used) to (by way of example only) command a bandwidth controlled actuator (eg, a stepper motor) to Any function that fires a number.
個別硬體及軟體“增益”可被用於軟體(以促進硬體更新能力)。Individual hardware and software "gains" can be used for software (to promote hardware renewal capabilities).
一控制器延遲(holdoff)也可被使用,使得(舉例而言)在一叢發之開始,在一些脈衝內沒有任何帶寬步進被允許,例如在一叢發開始之後的30個擊發內。A controller holdoff can also be used, such that, for example, at the beginning of a burst, no bandwidth steps are allowed within some pulses, such as within 30 firings after the start of a burst.
該帶寬控制系統之三個基本操作可利用一帶寬致動器(例如,一可變放大LNM)被執行。擊發處理可在每個擊發上發生(一擊發由LAM更新指出)。當帶寬目標變化發生時,帶寬目標變化處理可發生。The three basic operations of the bandwidth control system can be performed using a bandwidth actuator (e.g., a variable amplification LNM). The firing process can occur on each shot (one shot is indicated by the LAM update). Bandwidth target change processing can occur when a bandwidth target change occurs.
每當譜線中心(波長)分析模組(“LAM”)送回波長資料時(例如,基於一逐擊發基準),擊發處理邏輯可被執行。利用一擊發資料記錄,輸入信號可被檢查。該演算法可執行其計算且將該等結果移到相同的擊發資料記錄內。一帶寬分析模組(“BAM”)狀態信號可被用以決定是否可獲得新的帶寬資料(例如E95 帶寬資料)。接著該系統可嘗試濾除壞的或者其他無效的帶寬資料。The firing process logic can be executed whenever the line center (wavelength) analysis module ("LAM") returns the wavelength data (eg, based on a firing-by-shot basis). With a shot data record, the input signal can be checked. The algorithm can perform its calculations and move the results into the same firing data record. A Bandwidth Analysis Module ("BAM") status signal can be used to determine if new bandwidth data (eg, E 95 bandwidth data) is available. The system can then attempt to filter out bad or other invalid bandwidth data.
該帶寬控制系統(例如,使用一帶寬控制致動器(例如,一可變放大譜線窄化模組(“VMLNM”)的帶寬控制系統)可被要求以:(1)使帶寬穩定在某選定帶寬內,例如大約±50 fm;(2)以一選定的速率(例如,大約0.0003 fm/shot)自一選定的目標或設定點校正帶寬之誤差;(3)確保波長穩定性被維持,例如當使用具有帶寬致動器的帶寬控制允許不大於一選定值(例如,大約5 fm額外的55-擊發移動平均波長誤 差),以及不大於一選定值(例如,在波長誤差大約6 fm額外的55-擊發移動標準差);(4)包括一具有磁滯的不感帶,可被用以改變效能;(5)為阻止步進器馬達抖動,因此該步進器必須至少在一方向步進一選定的數目(例如,大約16個步階),在往另一方向步進之前;以及(6)提供用於帶寬目標變化,可在一選定的時間內達成,例如(舉例而言)若為200脈衝/秒之一最小擊發速率為大約10秒(對於一4 kHz脈衝重複率雷射系統)。The bandwidth control system (eg, using a bandwidth control actuator (eg, a variable amplification line narrowing module ("VMLNM") bandwidth control system) may be required to: (1) stabilize the bandwidth at some Within the selected bandwidth, for example, approximately ±50 fm; (2) correcting the error of the bandwidth from a selected target or set point at a selected rate (eg, approximately 0.0003 fm/shot); (3) ensuring that wavelength stability is maintained, For example, when using bandwidth control with a bandwidth actuator allows no more than a selected value (eg, about 5 fm extra 55-fired moving average wavelength error) Poor), and no more than a selected value (for example, an additional 55-spin shift standard deviation at a wavelength error of about 6 fm); (4) including a non-inductive band with hysteresis that can be used to change performance; (5) To prevent the stepper motor from shaking, the stepper must therefore be stepped through at least a selected number in one direction (eg, approximately 16 steps) before stepping in the other direction; and (6) provided for The change in bandwidth target can be achieved in a selected time, such as, for example, one of 200 pulses per second with a minimum firing rate of about 10 seconds (for a 4 kHz pulse repetition rate laser system).
因此,一濾波器可只在帶寬更新時被使用。在帶寬更新之間,其他功能可發生(例如,步進平滑化),但是大部分其他功能取決於被濾波的誤差。因此,當且若此不變化時,其他控制器狀態也保持恒定。該系統也可使用利用MOPA時序模式及BW步進器模式決定的帶寬控制演算法且也可使用一BW步進器馬達函數產生器/播放且提供BW步進器之“重設定”至基線放大。Therefore, a filter can be used only when the bandwidth is updated. Between bandwidth updates, other functions can occur (eg, step smoothing), but most other functions depend on the error being filtered. Therefore, if and if this does not change, the other controller states remain constant. The system can also use the bandwidth control algorithm determined using the MOPA timing mode and the BW stepper mode and can also use a BW stepper motor function generator/play and provide a "reset" of the BW stepper to baseline amplification. .
帶寬目標可能被要求在某選定的時間內改變,例如大約10秒。在帶寬目標改變期間,波長穩定性可不需要在規格內。一目標變化表示,該步進器可能需要以其最快的速率移動。該演算法可命令該步進器以盡可能最快的速率在正確的方向內移動,且當所量測的帶寬接近目標時停止該步進器。可選擇的方式是,該演算法可使用帶寬對步階曲線之知識以及絕對步階之位置感測以估計獲得目標帶寬所用的步階之正確數目。The bandwidth target may be required to change at a selected time, such as approximately 10 seconds. Wavelength stability may not be required within specifications during bandwidth target changes. A target change indicates that the stepper may need to move at its fastest rate. The algorithm can command the stepper to move in the correct direction at the fastest possible rate and stop the stepper when the measured bandwidth approaches the target. Alternatively, the algorithm can use the knowledge of the bandwidth versus step curve and the position sensing of the absolute step to estimate the correct number of steps used to obtain the target bandwidth.
若目前叢發內發射的擊發之數目小於或等於一被儲存 的值(表示在一叢發開始時用以阻止帶寬步進的擊發之數目)且若目標變化模式之狀態被致能(“1”),則該系統可基於回饋控制將此擊發所用的步階之數目設定為=0。基於回饋控制,此擊發所用的帶寬步階之總數目可被計算為用以命令一帶寬控制機制致動步進器(例如一可變放大稜鏡旋轉步進器)的微步之數目等於被命令的步階之數目。If the number of firings in the current burst is less than or equal to one is stored Value (representing the number of firings used to prevent bandwidth stepping at the beginning of a burst) and if the state of the target change pattern is enabled ("1"), the system can control the step used for this shot based on feedback control The number of steps is set to =0. Based on the feedback control, the total number of bandwidth steps used for this firing can be calculated as the number of microsteps used to command a bandwidth control mechanism to actuate the stepper (eg, a variable amplification 稜鏡 rotary stepper) equal to being The number of steps in the command.
該演算法輸出可被更新,例如,若用以命令該控制致動器(例如,該可變放大步進器)的微步之數目的絕對值大於0或若目前的目標變化狀態與先前的目標變化狀態不同,則該演算法輸出可被設定為1,否則被設定為0。該演算法輸出可以是表示新的步進器命令是否需要被發送給控制器以致動帶寬變化從而減少誤差信號(例如,是否致能一BWCM,如以下所討論的)的一信號,從而產生用以更新一帶寬控制機制致動步進器的一信號。該步進器可以是一可變放大LNM旋轉稜鏡。The algorithm output can be updated, for example, if the absolute value of the number of microsteps used to command the control actuator (eg, the variable amplification stepper) is greater than zero or if the current target change state is prior to the previous The algorithm output can be set to 1 if the target change state is different, otherwise it is set to 0. The algorithm output may be a signal indicating whether a new stepper command needs to be sent to the controller to actuate the bandwidth change to reduce the error signal (eg, whether a BWCM is enabled, as discussed below). A signal of the stepper is actuated by updating a bandwidth control mechanism. The stepper can be a variable amplification LNM rotation 稜鏡.
當一目標變化被檢測出時,該演算法可基於目前被濾波的誤差、先前帶寬目標以及新的帶寬目標決定一新的追蹤誤差(tracking error),即被濾波的誤差加先前目標減去新的目標。這可提供步進器移動之正確方向。該演算法接著也可重設定濾波器,使得被濾波的誤差等於新的追蹤誤差。該系統可命令該步進器在所需的方向內以最大速率移動(被稱為“迴旋”(slewing)),直到被濾除的帶寬誤差在為了能夠停止迴旋而沒有過衝的某選定的範圍內。該演算法也可檢查被濾波的誤差是否在迴旋期間改變正負號。一旦此 等條件中的任何一者未被滿足,控制器可返回到正常控制。When a target change is detected, the algorithm can determine a new tracking error based on the currently filtered error, the previous bandwidth target, and the new bandwidth target, ie, the filtered error plus the previous target minus the new one. The goal. This provides the correct direction for the stepper to move. The algorithm can then also reset the filter such that the filtered error is equal to the new tracking error. The system can command the stepper to move at a maximum rate in the desired direction (referred to as "slewing" until the filtered bandwidth error is in a selected one that is capable of stopping the spin and without overshooting Within the scope. The algorithm can also check if the filtered error changes the sign during the spin. Once this If any of the conditions are not met, the controller can return to normal control.
帶寬“尖峰”可能由於大的波長改變而發生。在一帶寬目標變化迴旋期間,由於帶寬步進與波長之耦合,波長也可能被影響。雖然該波長控制器可補償此等變化,但是其無法在叢發中間間隔期間如此做,使得若該步進器繼續迴旋,則波長可能改變。在叢發中間間隔之後,該波長控制器可能必須回應一新的且相對較大的波長誤差。這可能導致波長之一快速且大的變化,即使具有實質上以2 pm改變之能力,一非常快速(且細的)波長控制機制(例如,基於一RMAX 的PZT堆疊)或者改變光柵上的光束之入射角的稜鏡定位元件(作為一主波長控制源)。Bandwidth "spikes" may occur due to large wavelength changes. During a bandwidth target change cyclotron, the wavelength may also be affected due to the coupling of the bandwidth step to the wavelength. Although the wavelength controller can compensate for such variations, it cannot do so during the inter-band interval, such that if the stepper continues to gyrate, the wavelength may change. After the inter-band interval, the wavelength controller may have to respond to a new and relatively large wavelength error. This can result in a fast and large change in one of the wavelengths, even with the ability to change substantially at 2 pm, a very fast (and fine) wavelength control mechanism (eg, based on a RMAX PZT stack) or changing the grating The 稜鏡 positioning element of the incident angle of the beam (as a dominant wavelength control source).
在一BAM積分期間的波長之變化可由BAM感知為帶寬之增加。一般而言,波長變化越快,BAM測量內的正偏差越大。若波長變化足夠快,則在一些情況下,一異常大的“尖峰”可被BAM報告。在一目標改變期間,此等尖峰可能使該控制器將尖峰誤解釋為表示帶寬迴旋已完成且在達到目標之前很早就返回到正常控制。這可能使目標變化花費比選定的時間長得多的時間,例如,大於10秒。The change in wavelength during a BAM integration can be perceived by BAM as an increase in bandwidth. In general, the faster the wavelength changes, the greater the positive deviation within the BAM measurement. If the wavelength changes quickly enough, in some cases an unusually large "spike" can be reported by BAM. During a target change, such spikes may cause the controller to misinterpret the spike as indicating that the bandwidth swing has completed and returning to normal control very early before reaching the target. This may cause the target change to take much longer than the selected time, for example, greater than 10 seconds.
該控制器可實施幾種方法以濾除該等帶寬尖峰。該尖峰可能由在一短的時間上的一大的波長變化而引起。當波長在一BAM積分視窗期間改變多於某一量時忽略帶寬測量作為一濾波器,當波長之總的被包括的範圍大於某預定值時該濾波器忽略一帶寬測量。對實際帶寬(加雜訊)之實際限制值致能濾波,從而忽略大於某預定值的任何帶寬讀數(例 如,2x最大帶寬)。當一帶寬讀數被濾除/忽略時,上一個良好的(即,未被忽略的)測量值可在其位置上被使用。典型的值可以是最大被允許的波長TIR=300 fm及最大被允許報告的帶寬=1000 fm。The controller can implement several methods to filter out such bandwidth spikes. This spike may be caused by a large wavelength change over a short period of time. The bandwidth measurement is ignored as a filter when the wavelength changes more than a certain amount during a BAM integration window, and the filter ignores a bandwidth measurement when the total included wavelength range is greater than a predetermined value. The actual limit value of the actual bandwidth (add noise) is enabled to filter, thereby ignoring any bandwidth readings greater than a predetermined value (eg For example, 2x maximum bandwidth). When a bandwidth reading is filtered/ignored, the last good (ie, not ignored) measurement can be used at its location. Typical values may be the maximum allowed wavelength TIR = 300 fm and the maximum allowed bandwidth to be reported = 1000 fm.
一叢發之首次幾個擊發一般可由波長及能量內的大的且有時可重複的暫態被特徵化。該波長控制演算法可包含可阻止對該等叢發暫態過度反應的邏輯。然而,波長在此初始化期間對干擾較敏感。帶寬步進(這可能引起波長改變)可被阻止一叢發之第一被選擇數目的擊發,在本申請案中被稱為一叢發延遲。延遲的擊發之數目是一控制器操作參數且可以大約為3個擊發。The first few shots of a burst can generally be characterized by large and sometimes repeatable transients within wavelength and energy. The wavelength control algorithm can include logic that can prevent transient overreaction of the bursts. However, the wavelength is more sensitive to interference during this initialization. The bandwidth stepping (which may cause a wavelength change) may be prevented by a burst of the first selected number of firings, referred to in this application as a burst delay. The number of delayed firings is a controller operating parameter and can be approximately 3 firings.
依據另一可能的實施例(如第13圖中示意性地描述),用以控制帶寬及波長的具有4個稜鏡520、522、524及526的LNM被顯示。該等稜鏡中的兩者524及526可被與第4及5圖中所示的稜鏡524、526之致動器類似的致動器(圖未示)旋轉。一稜鏡526可被一步進器馬達致動器(圖未示)旋轉,且另一稜鏡524可被一PZT堆疊(圖未示)旋轉。該兩個稜鏡526及524可分別被用於波長之粗及細調整。它們的定位可根據來自一中心波長控制器系統的信號,回應中心波長由於目標變化或中心波長漂移而不在目標上。其他稜鏡中的至少一者可旋轉以供帶寬控制,例如稜鏡520。旋轉可利用一步進器馬達(圖未示)達成。In accordance with another possible embodiment (as schematically depicted in Figure 13), an LNM having four 稜鏡520, 522, 524, and 526 for controlling bandwidth and wavelength is displayed. Both of these 524 and 526 can be rotated by an actuator (not shown) similar to the actuators of 稜鏡524, 526 shown in Figures 4 and 5. One turn 526 can be rotated by a stepper motor actuator (not shown) and the other turn 524 can be rotated by a PZT stack (not shown). The two turns 526 and 524 can be used for coarse and fine adjustment of the wavelength, respectively. They are positioned to respond to signals from a central wavelength controller system that the center wavelength is not at the target due to target changes or center wavelength drift. At least one of the other ports can be rotated for bandwidth control, such as 稜鏡 520. Rotation can be achieved using a stepper motor (not shown).
第5圖以方塊圖形式描述了一包括帶寬及波長控制的雷射系統控制器200之一整體架構,一般與序號為6690704 的美國專利(其以參照方式被併入本文)中所討論的控制器相同,附加一帶寬控制模組(“BWCM”)220及一可變放大譜線窄化模組(“VMLNM”)222。一發射控制平臺(“FCP”)處理器202可控制(例如)一個單一腔室雷射系統(例如,Cymer之7000系列雷射系統)內的電極之間的放電之發射或者一種源雷射放大器配置(例如Cymer之XLA系列的MOPA雷射系統或者XLR系列的環功率放大器MOPO雷射系統)內的多數個雷射腔室中的每個內的電極之間的放電之發射。該FCP202可使用控制演算法軟體且提供控制信號給一發射控制通信器(“FCC”)204。Figure 5 depicts, in block diagram form, an overall architecture of a laser system controller 200 including bandwidth and wavelength control, generally with the serial number 6690704 The controllers discussed in the U.S. Patent (which is incorporated herein by reference) are the same, and a bandwidth control module ("BWCM") 220 and a variable amplification line narrowing module ("VMLNM") 222 are attached. . A launch control platform ("FCP") processor 202 can control, for example, the emission of discharges between electrodes within a single chamber laser system (eg, Cymer's 7000 Series laser system) or a source laser amplifier Emission of discharge between electrodes in each of a plurality of laser chambers (e.g., the MOPA laser system of the XLA series of Cymer or the MOPO laser system of the XLR series). The FCP 202 can use control algorithm software and provide control signals to a transmit control communicator ("FCC") 204.
該FCP 202可回應來自一雷射控制處理器(“LCP”)206的命令信號且與該LCP 206進行通訊。該FCC 204可自一光束分析模組(“BAM”)210(有些類似‘704專利中討論的頻譜分析模組(“SAM”)(用於帶寬)以及一譜線中心分析模組(“LAM”)212(用於中心波長)接收波長及帶寬資訊,且可中斷該FCP 202以執行一波長或帶寬控制演算法或其二者。該FCC 204也可將FCP 202命令傳給一帶寬控制模組(“BWCM”)220,該BWCM 220可被用以命令所有被用以控制帶寬或波長的致動器,例如可存在一可變放大譜線窄化模組(“VMLNM”)222內。VMLNM 222及其致動器之狀態可透過該FCC 204傳遞回給該FCP 202。The FCP 202 can respond to command signals from a laser control processor ("LCP") 206 and communicate with the LCP 206. The FCC 204 is available from a Beam Analysis Module ("BAM") 210 (some similar to the Spectrum Analysis Module ("SAM") (for bandwidth) and a Line Center Analysis Module ("LAM" discussed in the '704 patent) 212) (for center wavelength) receives wavelength and bandwidth information, and may interrupt the FCP 202 to perform a wavelength or bandwidth control algorithm or both. The FCC 204 may also pass the FCP 202 command to a bandwidth control mode. Group ("BWCM") 220, which can be used to command all actuators used to control bandwidth or wavelength, such as may exist within a variable amplification line narrowing module ("VMLNM") 222. The state of the VMLNM 222 and its actuators can be communicated back to the FCP 202 via the FCC 204.
第6圖以方塊圖形式描述了一代表性的雷射系統“植入模型”,其中一帶寬(或者可能是波長)步進器馬達步階命令232可被輸入給一加法器234且與一樣本延遲236之一輸出 求和以提供一輸入給一步階對BW查找,該步階對BW查找產生一期望的帶寬值,該期望的帶寬值被輸入給一加法器242且與來自干擾方塊240的一代表性干擾求和。在一樣本延遲方塊244之後,該加法器242之輸出在加法器246內與來自常數方塊248的一常數以及來自雜訊方塊247的雜訊求總和以產生被量測的帶寬在輸出249上的一表示。Figure 6 depicts a representative laser system "implantation model" in block diagram form in which a bandwidth (or possibly wavelength) stepper motor step command 232 can be input to an adder 234 and One output of this delay 236 The summation provides an input to a step-by-step BW lookup that produces a desired bandwidth value for the BW lookup, the desired bandwidth value being input to an adder 242 and a representative interference request from the interference block 240. with. After the same delay block 244, the output of the adder 242 sums up a constant from the constant block 248 and the noise from the noise block 247 in the adder 246 to produce the measured bandwidth on the output 249. One said.
第7圖顯示了一帶寬控制器250之一說明性例子。該控制器250可具有帶寬(或可能是波長)目標252、被量測的帶寬(波長)254及波長TIR 256之輸入,其等的後兩者被輸入到一“壞”帶寬量測處理器257,其“好”帶寬之一輸出在一加法器258內與該目標帶寬輸入252求和以提供一輸入給一雜訊濾波器260。若該帶寬測量值需被濾除/忽略(例如,因為該測量值或TIR太大),則方塊257之輸出將是一先前被量測的“好”帶寬,否則該被量測的帶寬可通過方塊257。Figure 7 shows an illustrative example of a bandwidth controller 250. The controller 250 can have a bandwidth (or possibly wavelength) target 252, a measured bandwidth (wavelength) 254, and an input of wavelength TIR 256, the latter two of which are input to a "bad" bandwidth measurement processor. 257, one of its "good" bandwidth outputs is summed with the target bandwidth input 252 in an adder 258 to provide an input to a noise filter 260. If the bandwidth measurement needs to be filtered/ignored (eg, because the measurement or TIR is too large), the output of block 257 will be a previously measured "good" bandwidth, otherwise the measured bandwidth may be Pass block 257.
該雜訊濾波器260之輸出提供一輸入給一步階命令路徑、一模式選擇路徑及一迴旋步進路徑。該步進命令路徑可包括具有磁滯“接通/截止”方塊262的一不感帶,其一例子在第9圖中被較詳細地描述。若具有磁滯的不感帶之輸出以回饋致動致能/啟動模式(例如,a 1),則該乘法器270之輸出是該雜訊濾波器260之輸出,以及若其是以回饋致動禁能/關閉模式0,則該乘法器270之輸出是0。該乘法器270之輸出在控制增益放大器272內被放大一增益因數K且通過一命令飽和方塊274到一步階平滑器276,該步階平滑器276之一例子在第8圖中被詳細地顯示。該命令飽和方塊可被用以限 制帶寬步進速率對中心波長控制之影響。一限制值可被建立等於每一畫面的最大步階(例如,每次BAM/帶寬測量更新0.1次擊發(標稱為30),在此一典型情況下將是3步階)。The output of the noise filter 260 provides an input to the one-step command path, a mode selection path, and a whirling step path. The step command path may include a non-inductive strip having a hysteresis "on/off" block 262, an example of which is described in more detail in FIG. If the non-inductive output with hysteresis is fed back to the enable enable/start mode (eg, a 1), the output of the multiplier 270 is the output of the noise filter 260 and if it is actuated by feedback When disable/off mode 0, the output of the multiplier 270 is zero. The output of the multiplier 270 is amplified by a gain factor K in the control gain amplifier 272 and passed through a command saturation block 274 to the step-by-step smoother 276, an example of which is shown in detail in FIG. . The command saturation block can be used to limit The effect of the bandwidth step rate on the center wavelength control. A limit value can be established equal to the maximum step of each picture (eg, each time the BAM/bandwidth measurement updates 0.1 times the shot (nominally 30), in this case it will be 3 steps).
該模式選擇路徑可包括一控制模式選擇器264,其一例子在第10圖中被詳細地顯示。該模式選擇器264接收該雜訊濾波器260之輸出(在一BW誤差輸入端上)以及一目標變化檢測器268之輸出為一輸入,該目標變化檢測器268具有至來自輸入252的帶寬目標之一輸入端。該目標變化檢測器268之輸出形成該模式選擇器264之目標變化輸入端的一輸入。該迴旋步進路徑可包括接收該雜訊濾波器260之輸出的一正負號方塊266,該正負號方塊266之輸出在一目標變化迴旋步進放大器278內被放大一因數N。The mode selection path may include a control mode selector 264, an example of which is shown in detail in FIG. The mode selector 264 receives the output of the noise filter 260 (on a BW error input) and the output of a target change detector 268 is an input having a bandwidth target from the input 252. One of the inputs. The output of the target change detector 268 forms an input to the target change input of the mode selector 264. The whirling step path can include a sign block 266 that receives the output of the noise filter 260, the output of the sign block 266 being amplified by a factor N within a target change whirling stepper amplifier 278.
該等路徑中的每個之輸出提供輸入給一三極開關280之個別終端,其等之輸出是一步階命令284。The output of each of the paths provides input to an individual terminal of a three-pole switch 280, the output of which is a one-step command 284.
第9圖以方塊圖形式描述了一不感帶磁滯控制方塊262,其可將該雜訊濾波器260之輸出作為一輸入290,如第7圖中所描述的。該輸入290可被提供給一絕對值函數方塊292,該絕對值函數方塊292之輸出可被提供給一中繼方塊294,該中繼方塊294可包含(作為一例子)具有磁滯的一對稱開關以提供一“接通/截止”輸出296。當帶寬誤差(或者可能是利用帶寬本身內的不感帶量測的帶寬,與帶寬誤差相反)大於外/高不感帶值時,該對稱開關294可作用以產生一“接通”輸出(“1”),以及當其小於內/低帶寬值時,產生一“截止”(“0”)。當與一高或低不感帶值相比使用誤差信號之絕對 值時,使用帶寬誤差只是在邏輯上易於實施。若先前的輸出是一“1”/“接通”,則當帶寬誤差在高/外不感帶值與低/內不感帶值之間時,該開關294可產生一“接通”輸出,及當先前的輸出是“0”/“截止”時反之亦然。這是本文中的磁滯之含義。Figure 9 depicts, in block diagram form, a non-inductive hysteresis control block 262 that can take the output of the noise filter 260 as an input 290, as depicted in Figure 7. The input 290 can be provided to an absolute value function block 292, the output of which can be provided to a relay block 294, which can include (as an example) a symmetry with hysteresis The switch provides an "on/off" output 296. The symmetrical switch 294 can act to generate an "on" output when the bandwidth error (or possibly the non-inductively measured bandwidth within the bandwidth itself, as opposed to the bandwidth error) is greater than the outer/high non-inductive value ("1 "), and when it is less than the inner/low bandwidth value, a "cutoff" ("0") is generated. Absolute use of error signals when compared to a high or low sense When using values, using bandwidth errors is only logically easy to implement. If the previous output is a "1" / "on", the switch 294 can generate an "on" output when the bandwidth error is between the high/outer sensed value and the low/inner sensed value, and The reverse is also true when the previous output is "0" / "off". This is the meaning of hysteresis in this article.
如第8圖中所描述,一步階平滑器276可將一步階命令作為一輸入,例如來自第7圖中說明的命令飽和方塊274的步階命令。該步階平滑器276可包括一除法器,該除法器將前進的步階之輸入步階命令c除以前進c數目的步階所用的擊發之數目(或時間)T。該除法器340之輸出提供一輸入給一加法器342及一截取方塊360。As described in FIG. 8, the step-by-step smoother 276 can take a one-step command as an input, such as a step command from the command saturation block 274 illustrated in FIG. The step smoother 276 can include a divider that divides the input step command c of the advanced step by the number (or time) T of shots used to advance the c number of steps. The output of the divider 340 provides an input to an adder 342 and a block 360.
該加法器342之輸出被提供給乘法器方塊346,該乘法器方塊346之輸出X步階在捨入方塊350內被捨到最接近的整數。方塊350之輸出形成s步階之一輸出命令,被提供給如第7圖中所描述的開關280。該乘法器方塊346之輸出也在一加法器348內自該舍入方塊350之輸出被減去以提供一輸入給一樣本延遲344,該樣本延遲344之輸出提供一輸入給該加法器342。需要確保具有對帶寬控制致動器步階之一限制值以限制對波長控制之壞的影響(例如,波長鎖定),這可能每10個擊發1 BW步階以維持WL鎖定(其不應是一平均值)。BW控制迴圈每隔30個擊發(可對應BAM更新速率)被執行,當且若控制迴圈期望在該等30個擊發期間具有最大3個步階),這將平均化為僅1步階/10擊發。然而,若該BWCM一次命令所有三個,則其他系統要求可能被干擾。存在在 30個擊發期間將該等步階均勻分佈之需求,這是該步階平滑器276執行的。The output of the adder 342 is provided to a multiplier block 346 whose output X step is rounded to the nearest integer within the rounding block 350. The output of block 350 forms an output command of one of the steps of s, which is provided to switch 280 as described in FIG. The output of the multiplier block 346 is also subtracted from the output of the rounding block 350 in an adder 348 to provide an input to the same local delay 344, the output of which provides an input to the adder 342. There is a need to ensure that there is a limit on the bandwidth control actuator step to limit the effects of wavelength control (eg, wavelength lock), which may be every 10 shots 1 BW step to maintain WL lock (which should not be an average). The BW control loop is executed every 30 firings (corresponding to the BAM update rate), and if the control loop is expected to have a maximum of 3 steps during the 30 firings, this will average to only 1 step. /10 shots. However, if the BWCM commands all three at a time, other system requirements may be disturbed. There is a need to evenly distribute the steps during 30 firings, which is performed by the step smoother 276.
該輸入(被命令的c步階)也被提供給一加法器364,其在該加法器364內與加法器370內的對該捨入方塊350之輸出與方塊368內被延遲的輸出之一個單一樣本延遲求和之結果求總和,其中該加法器364之輸出提供一輸入給一個單一樣本延遲方塊366。在方塊366內的一樣本延遲之後,方塊364之輸出提供一輸入給一絕對值方塊354。方塊354之輸出在方塊352內被比較以檢查其是否大於一值“r”,該值“r”源於該截取方塊360,其中方塊340內的除法之結果藉由移除該結果之任何十進制部分而被截取且在加法器358內與一常數(例如1.0)求和,且在乘法器方塊356內乘以一值(例如,0.5)以提供一輸入r給比較器方塊352。在虛線之外的該步階平滑器256之元件確保步進在被命令的所需的步階之數目(即,c)之後停止。否則,若對於一BAM更新之下一次不具有一BAM更新,則該步進器可能僅保持步進該帶寬控制機制,即使一不感帶下/上限制值被經過。The input (command c step) is also provided to an adder 364 within the adder 364 and one of the output of the rounding block 350 and the delayed output in block 368 in adder 370. The result of the single sample delay sum is summed, wherein the output of the adder 364 provides an input to a single sample delay block 366. After the same delay in block 366, the output of block 364 provides an input to an absolute block 354. The output of block 354 is compared in block 352 to check if it is greater than a value "r" derived from the truncation block 360, wherein the result of the division in block 340 is removed by removing any decimal of the result. The portion is truncated and summed with a constant (e.g., 1.0) in adder 358 and multiplied by a value (e.g., 0.5) within multiplier block 356 to provide an input r to comparator block 352. The elements of the step smoother 256 outside the dashed line ensure that the step stops after the number of steps required to be commanded (i.e., c). Otherwise, if there is no BAM update for a BAM update next time, the stepper may only keep stepping the bandwidth control mechanism even if a no-in/down limit value is passed.
該控制器250可具有幾個參數,其等之值可被選擇且代表值在括弧內被注明,例如,雜訊濾波器係數C(0.9735)、控制器增益K(1)、不感帶內及外限制值(分別為(1.0 fm)及do(9.5 fm))、命令飽和限制值L(每個BAM更新期間2個步階)、目標-變化-完成錯誤限制值M(15 fm)、最大被允許的波長TIR(300-400 fm)以及最大被允許報告的帶寬(600-1000 fm)。The controller 250 can have several parameters, the values of which can be selected and the representative values are noted in parentheses, for example, the noise filter coefficient C (0.9735), the controller gain K(1), and the in-band sense. And external limit values ((1.0 fm) and do (9.5 fm), respectively), command saturation limit value L (2 steps per BAM update period), target-change-complete error limit value M (15 fm), The maximum allowed wavelength TIR (300-400 fm) and the maximum allowed bandwidth (600-1000 fm).
若給定此等因素(如感測器雜訊、效能要求以及強健性),則當決定閉迴路內的整體效能時,該等參數可以一高非線性方式合併。因此,申請人已決定選擇開始較鬆散耦合的參數。最大被允許的TIR基於在一目標變化迴旋期間的實驗被選擇,其被認為是一最糟糕情形持續操作。對於一示範性ArF雷射系統,在正常操作情形中,最大可能的帶寬是大約300-500 fm,因此次數2給出了被選擇的限制值。Given these factors (such as sensor noise, performance requirements, and robustness), these parameters can be combined in a highly nonlinear manner when determining the overall performance within a closed loop. Therefore, the applicant has decided to choose a parameter that starts to be loosely coupled. The maximum allowed TIR is selected based on an experiment during a target change maneuver, which is considered to be a worst case continuous operation. For an exemplary ArF laser system, in normal operating conditions, the maximum possible bandwidth is approximately 300-500 fm, so the number 2 gives the selected limit value.
在一ArF雷射系統之例子中,M被選擇,因為一重濾波測試信號可能在實際信號與測試信號之間具有大的延遲,從而導致早停止一目標變化迴旋以阻止超量的過衝。對於L,因為帶寬及波長步進器可能影響帶寬,所以波長步進器可移動以補償一帶寬步進器移動(一控制中心之帶寬控制致動),例如透過該波長控制器內的PZT去飽和。由於帶寬步進產生的波長之變化可被波長步進抵消。對於K(具有波長步進器速率限制),該控制器具有實質上無限的增益邊限。控制增益被選擇,因此命令有效地總是飽和,從而提供最快速的回應時間。當該帶寬步進器每步階提供~0.005 fm(以每30個擊發2步階),則每個擊發0.00033 fm滿足其他系統要求。對於do =9.5,調諧內不感帶限制值di ,(例如,用於客戶帶寬控制需求)以及利用重濾波表示被濾除的值是實際的即時帶寬(除了在帶寬(例如,步階)快速變化下),do 可提供於實際帶寬之標稱整個不感帶。帶寬測量雜訊近似於白高斯(標準偏差~20 fm,帶寬之一總範圍小於(2*9.5=19 fm))是合理的以限制步進器之致動。內不感帶限制值di = 1.0可最大化不感帶磁滯,最小化一控制中心在一帶寬控制致動步進器或其他致動器的命令內的抖動。而且,當帶寬測量在大約一1 fm解析度時,若該內不感帶被設定小於1 fm,則其是無效的。對於C,增加的穩定性以及阻止雜訊濾波器抖動也可能增加延遲,其過度的量是不被期望的。命令飽和可自波長變化與波長及帶寬控制器致動步階之比率選擇,且期望以一個單一波長步階補償一帶寬致動步階且捨入到整數步,因為若被舍入,則該波長步進器可能使帶寬步進落後。對於一30個擊發之BAM積分期間,該波長控制器可允許每30個擊發1個波長步階。因此L=2(其是大約每個擊發0.00033)滿足系統要求。若步階之大小需增加(或者它們對帶寬之影響),則這可能減少增益邊限。In the case of an ArF laser system, M is selected because the one-filter test signal may have a large delay between the actual signal and the test signal, resulting in early stopping of a target change cyclotron to prevent excessive overshoot. For L, because the bandwidth and wavelength stepper may affect the bandwidth, the wavelength stepper can be moved to compensate for a bandwidth stepper movement (a control center bandwidth control actuation), such as through the PZT in the wavelength controller. saturation. The change in wavelength due to the bandwidth step can be offset by the wavelength step. For K (with wavelength stepper rate limit), the controller has a virtually unlimited gain margin. The control gain is selected so the command is always always saturated, providing the fastest response time. When the bandwidth stepper provides ~0.005 fm per step (2 steps per 30 shots), each shot has 0.00033 fm to meet other system requirements. For d o = 9.5, the tuning does not sense the limit value d i , (for example, for customer bandwidth control requirements) and the value filtered by the re-filtering representation is the actual instantaneous bandwidth (except in the bandwidth (eg, step) Under rapid changes), d o can be provided for the nominal bandwidth of the actual bandwidth. Bandwidth measurement noise is similar to white Gaussian (standard deviation ~20 fm, one of the total bandwidth is less than (2*9.5=19 fm)) is reasonable to limit the actuation of the stepper. The internal insufficiency limit value d i = 1.0 maximizes the non-inductive hysteresis, minimizing the jitter of a control center within a command of a bandwidth controlled actuation stepper or other actuator. Moreover, when the bandwidth is measured at a resolution of about 1 fm, it is ineffective if the inner non-inductive band is set less than 1 fm. For C, increased stability and blocking of noise filter jitter may also increase latency, an excessive amount of which is undesirable. Command saturation can be selected from the ratio of wavelength variation to wavelength and bandwidth controller actuation steps, and it is desirable to compensate a bandwidth actuation step with a single wavelength step and round to integer steps because if rounded, then The wavelength stepper may make the bandwidth step backwards. For a 30-shot BAM integration period, the wavelength controller can allow 1 wavelength step to be fired every 30 shots. Therefore L = 2 (which is approximately 0.00033 per shot) meets the system requirements. If the size of the steps needs to be increased (or their effect on bandwidth), this may reduce the gain margin.
雜訊濾波器之步階回應可以是: yk =u(1-ck )+y0 +vk The step response of the noise filter can be: y k =u(1-c k )+y 0 +v k
其中u是步階輸入之大小,y0
是初始輸出,C是係數,v是被濾除的雜訊且k=30*(擊發數目)。當一步進干擾發生時控制器250在不感帶內,控制動作可能無法啟動,直到被濾波的誤差增加到do
以上,其所需的時間是由濾波器產生的一初始延遲。當y越過不感帶時,解k:
其中已知C<1。假設在實際被濾波的帶寬到達不感帶之前(由於雜訊且忽略雜訊“尖峰”),不感帶(平均)為1西格
馬,其中do
>y0
且避免u+y0
<do
(表示u+y0
-do
>0),當u大且u+y0
-do
小時,k可被最大化。即使如此,可能具有干擾與初始條件之一組合,使得被濾波的誤差用幾乎無限的時間經過do
,與C無關。當利用以1 fm解析度量測的帶寬(u+y0
-do
之最小值=1是合理的)以及利用do
=9.5(最小化u+y0
-do
=1的u之最大值是u=2*do
+1=20),一初始條件可被設置在不感帶之“底部”,且一步進干擾足以離開不感帶之“頂部”。第一階濾波器響應(無過衝)可能用最長的時間退出不感帶。當以每個樣本30個擊發以及200擊發/秒之最小擊發累加速率,離開不感帶的最大時間可由以下決定:
其中σs 是感測器雜訊標準偏差,(舉例而言)等於20 fm。這可定義一絕對最差情形,且一蒙特卡羅研究顯示典型的延遲小於0.5秒,得到一10秒之延遲(一合理的選擇)使得一C=0.9735之濾波器係數是合理的。Where σ s is the sensor noise standard deviation, for example, equal to 20 fm. This defines an absolute worst case, and a Monte Carlo study shows that the typical delay is less than 0.5 seconds, resulting in a 10 second delay (a reasonable choice) such that a filter coefficient of C = 0.9735 is reasonable.
一步進器馬達與一BWCM之一組合可作為一具有速率限制值(4000微步/秒)的累加器(積分器),其也可以是一完全無雜訊。BW是絕對步進器位置之一非線性函數,且也可具有從WL至BW之可忽略的耦合,這可允許個別地關閉BW控制迴路且與其他迴路無關。然而,從BW耦合到WL以及導出WL誤差5 fm之一要求可能需要特別考量。雖然被控制的植入可作為一自然積分器(具有良好的雜訊拒絕特性),但 是也可能需要額外的濾波以幫助阻止步進器命令內的抖動。A stepper motor in combination with one of the BWCMs can be used as an accumulator (integrator) with a rate limit value (4000 microsteps per second), which can also be completely noise free. BW is a non-linear function of absolute stepper position and may also have negligible coupling from WL to BW, which may allow the BW control loop to be individually turned off and independent of other loops. However, coupling from BW to WL and deriving WL error One of the 5 fm requirements may require special consideration. Although the controlled implant can be used as a natural integrator (with good noise rejection characteristics), additional filtering may be required to help prevent jitter within the stepper commands.
該系統可尋求將該帶寬控制機制步進器移到一基線位置之方法,例如一基線放大或一基線孔徑口或類似者。這可藉由使用限制開關(例如,在該LNM內)被執行,發出大量的步階(例如)以最極放大且等待來自一個別限制開關的一中斷信號,這使該BWCM由於來自該限制開關的信號而停止命令步進器致動。同樣地可被應用於其他帶寬控制致動器,例如一可調整孔徑。該限制開關位置應被設定到已知帶寬設定,例如一已知放大或一已知孔徑大小及位置。當此功能被實施時,也可測量且更新一BW對步階曲線。The system may seek to move the bandwidth control mechanism stepper to a baseline position, such as a baseline amplification or a baseline aperture or the like. This can be performed by using a limit switch (eg, within the LNM), issuing a large number of steps (for example) to maximize amplification and waiting for an interrupt signal from a different limit switch, which causes the BWCM to come from the limit The signal of the switch stops the command stepper actuation. The same can be applied to other bandwidth controlled actuators, such as an adjustable aperture. The limit switch position should be set to a known bandwidth setting, such as a known amplification or a known aperture size and position. When this function is implemented, a BW versus step curve can also be measured and updated.
申請人已模擬此一帶寬控制系統且自此模擬決定,系統響應可由演算法BW步進器速率限制值主導(例如,~0.0005 fm/shot)。濾波可有效地改良雜訊響應以使不感帶縮小。控制器增益可被設定足夠高,因此該步進器命令總是飽和或者“截止”。該系統可達到誤差=(內不感帶)+(~3σ被濾波的雜訊),其誤差當雜訊尖峰觸發偶然步進時,“潛動”較低(假設無干擾)。該潛動可藉由增加磁滯之大小被最小化。不感帶加雜訊濾波器可有效地消除抖動。該系統可以是高度強健,具有一實際上無限制的增益邊限。該BW步進器速率限制值以及不感帶可阻止雜訊將不穩定移動注入該系統。The Applicant has simulated this bandwidth control system and since this simulation decision, the system response can be dominated by the algorithm BW stepper rate limit value (eg, ~0.0005 fm/shot). Filtering can effectively improve the noise response to reduce the band. The controller gain can be set high enough so the stepper command is always saturated or "off". The system can achieve error = (without internal sensing) + (~3σ filtered noise), the error is low when the noise spike triggers the accidental step (assuming no interference). This dive can be minimized by increasing the magnitude of the hysteresis. The non-inductive noise filter can effectively eliminate jitter. The system can be highly robust with a virtually unlimited gain margin. The BW stepper rate limit value and no sense band prevent noise from injecting the system into the system.
一中心波長選擇機制可包括一分散光學元件,且該中心波長選擇稜鏡及/或其他中心波長選擇光學元件可控地 調整該分散光學元件上的光束之入射角。該差動時序系統可包含一粗帶寬控制調整,或者反之亦然。粗及細帶寬及/或中心波長控制致動之各種組合可被使用。A center wavelength selection mechanism can include a dispersive optical element, and the center wavelength selection chirp and/or other center wavelength selective optics are controllably The angle of incidence of the beam on the dispersive optical element is adjusted. The differential timing system can include a coarse bandwidth control adjustment, or vice versa. Various combinations of coarse and thin bandwidth and/or center wavelength control actuation can be used.
依據另一可能的實施例(在第13圖中被示意性地描述),一具有4個用以控制帶寬及波長的稜鏡520、522、524、526之LNM被顯示。其中兩稜鏡524及526可被與第4及11圖中的稜鏡524、526之致動器類似的致動器(圖未示)旋轉。一稜鏡526可被一步進器馬達致動器(圖未示)旋轉,且另一稜鏡524可被一PZT堆疊(圖未示)旋轉。該兩稜鏡526及524分別可被用於波長之粗調整及細調整。它們的定位可根據來自一中心波長控制器系統的信號,回應中心波長由於目標變化或中心波長漂移而不在目標上。其他稜鏡中的至少一者可旋轉用於帶寬控制,例如稜鏡520。旋轉可利用一步進器馬達達成(圖未示)。According to another possible embodiment (schematically depicted in Figure 13), an LNM having four 稜鏡520, 522, 524, 526 for controlling bandwidth and wavelength is displayed. Two of the ports 524 and 526 can be rotated by actuators (not shown) similar to the actuators of the ports 524, 526 of Figures 4 and 11. One turn 526 can be rotated by a stepper motor actuator (not shown) and the other turn 524 can be rotated by a PZT stack (not shown). The two turns 526 and 524 can be used for coarse adjustment and fine adjustment of the wavelength, respectively. They are positioned to respond to signals from a central wavelength controller system that the center wavelength is not at the target due to target changes or center wavelength drift. At least one of the other ports can be rotated for bandwidth control, such as 稜鏡 520. Rotation can be achieved with a stepper motor (not shown).
一種方法可被用以控制一種源雷射放大器雷射配置(例如,一MOPA或MOPO雷射系統)之頻譜輪廓(帶寬),其可能較適用於一MOPO雷射,因為其可減少輸入到第二(放大器)級512的MO能量。此方法可能不依靠dtMOPA時序控制,其之使用可能對一或多個其他雷射系統操作參數(例如,能量穩定性)具有一不期望的負面效應,雖然dtMOPA時序控制可被用以擴充此處描述的裝置及方法。該裝置及方法可被用以提供一雷射控制頻譜之對稱性及非對稱性控制。A method can be used to control the spectral profile (bandwidth) of a source laser amplifier laser configuration (eg, a MOPA or MOPO laser system), which may be more suitable for a MOPO laser because it reduces input to The MO energy of the second (amplifier) stage 512. This method may not rely on dtMOPA timing control, its use may have an undesirable negative effect on one or more other laser system operating parameters (eg, energy stability), although dtMOPA timing control can be used to expand here. The device and method described. The apparatus and method can be used to provide symmetry and asymmetry control of a laser control spectrum.
使用一稜鏡及/或折疊式反射鏡以及基於光柵頻譜窄 化方法的雷射之輸出頻譜在(舉例而言)垂直於該光柵之鋸齒結構之方向內可能具有波長之一空間非均勻性。第16圖描述了與光束經過的孔徑之大小相依的帶寬變化之例子。藉由以(舉例而言)一可調整孔徑(例如,第14圖中的158或者第15圖中的610,或者例如序列號為11/173,988的共同申請的專利申請案中所示的,該專利名稱為“ACTIVE BANDWIDTH CONTROL FOR A TUNED LASER”,於2005年6月30日提出申請,在此以參照方式被併入本文,第14圖取自此專利)自該主振盪器選擇雷射光束之一部分且將部分光束注入該功率放大器或功率振盪器(例如,第3圖中示意性描述的放大器512),系統輸出頻譜帶寬可被控制。被用作第二級(放大器)的功率放大器或功率振盪器(例如,第3圖中的512)可能需要某一輸入光束大小,這可由兩透鏡或者類似裝置(例如,一擴束器(舉稜鏡為例))之一組合或者另一可調整孔徑提供,以在其經過孔徑之後調整光束大小且使其成形,例如擴張光束及使其平行,以選擇一期望的部分以供調整或選擇帶寬之目的。舉一例,在第15圖中示意性描述的一可調整光束擴展準直器600可被使用。Use a 稜鏡 and / or folding mirror and narrow based on the grating spectrum The output spectrum of the laser of the method may have a spatial non-uniformity of wavelengths, for example, in a direction perpendicular to the sawtooth structure of the grating. Figure 16 depicts an example of a change in bandwidth that depends on the size of the aperture through which the beam passes. By, for example, an adjustable aperture (e.g., 158 in Fig. 14 or 610 in Fig. 15, or as shown in the co-pending patent application Serial No. 11/173,988, the The patent name is "ACTIVE BANDWIDTH CONTROL FOR A TUNED LASER", filed on June 30, 2005, which is incorporated herein by reference in its entirety, in its entirety, in its entirety, the entire entire A portion of the beam is injected into the power amplifier or power oscillator (e.g., amplifier 512, which is schematically depicted in FIG. 3), and the system output spectral bandwidth can be controlled. A power amplifier or power oscillator used as a second stage (amplifier) (eg, 512 in Figure 3) may require some input beam size, which may be by two lenses or similar devices (eg, a beam expander)稜鏡 稜鏡 ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) The purpose of bandwidth. As an example, an adjustable beam expanding collimator 600, schematically depicted in Fig. 15, can be used.
一帶寬監測器(例如,位於第3圖中的一帶寬分析模組(“BAM”)516內)可提供一回饋信號給一帶寬控制器(例如,第15圖中的620),該帶寬控制器可使用帶寬信號調整經過該可調整孔徑610的光束之部分,例如在此情況下,該光束選擇孔徑大小及光束成形都被控制以選擇帶寬及光束大小給該雷射系統之放大級以提供頻譜形狀(帶寬)之對稱及非 對稱控制,這可(舉例而言)在該可調整光束擴展器/準直器600內被執行。將明白的是,在該可調整孔徑之前的種源雷射光束(例如,MO光束)之帶寬應足夠大以提供在可調整孔徑之後的一期望範圍的頻譜帶寬。A bandwidth monitor (e.g., within a Band Analysis Module ("BAM") 516 in Figure 3) can provide a feedback signal to a bandwidth controller (e.g., 620 in Figure 15), the bandwidth control The bandwidth signal can be used to adjust a portion of the beam passing through the adjustable aperture 610, for example, in which case the beam selection aperture size and beam shaping are controlled to select a bandwidth and beam size for the amplification stage of the laser system to provide Symmetry and non-symmetry of spectrum shape (bandwidth) Symmetrical control, which can be performed, for example, within the adjustable beam expander/collimator 600. It will be appreciated that the bandwidth of the source laser beam (e.g., MO beam) prior to the adjustable aperture should be large enough to provide a desired range of spectral bandwidth after the aperture is adjustable.
若期望,依據本揭露之標的,為了除了帶寬之外的其他雷射操作參數之利益(例如,脈衝能量、劑量穩定性及類似者),dtMOPA時序可被獨立用以允許MOPA雷射以其最佳dtMOPA時序操作,同時該可調整孔徑610或其他形式的主動帶寬控制可結合一或多個其他帶寬控制致動器(作為粗或細調整器或具有相對相等的調整速度)被使用,作為一帶寬選擇致動器(控制中心)以選擇帶寬。可選擇的方式是,該dtMOPA帶寬選擇致動器只可被用於細調整,因此就其他操作觀點而言(例如,脈衝能量穩定性、劑量穩定性或類似者),不需要大大地偏離最佳dtMOPA。If desired, in accordance with the subject matter of this disclosure, for the benefit of laser operating parameters other than bandwidth (eg, pulse energy, dose stability, and the like), the dtMOPA timing can be used independently to allow the MOPA laser to be the most Good dtMOPA timing operation, while the adjustable aperture 610 or other form of active bandwidth control can be used in conjunction with one or more other bandwidth controlled actuators (as coarse or fine adjusters or with relatively equal adjustment speeds) as a The bandwidth selects the actuator (control center) to select the bandwidth. Alternatively, the dtMOPA bandwidth selection actuator can only be used for fine adjustments, so that from other operational perspectives (eg, pulse energy stability, dose stability, or the like), there is no need to deviate significantly from the most Good dtMOPA.
因為一種源雷射放大器雷射(例如MOPA或MOPO)之能量穩定性可能受到輸入到PA/PO的MO能量之強烈影響,所以可能期望具有對MO及PA/PO之個別電壓控制以調整且控制獨立於放大器部分的MO能量輸出,例如PA/PO。Since the energy stability of a source laser amplifier laser (eg MOPA or MOPO) may be strongly influenced by the MO energy input to the PA/PO, it may be desirable to have individual voltage control for MO and PA/PO to adjust and control Independent of the MO energy output of the amplifier section, such as PA/PO.
一可調整孔徑可以是矩形的以在光束之短軸內調整,其在申請人之讓渡人的雷射系統(例如,Cymer之7XXX系列或XLA或LXLR系列雷射系統)內一般是在水平方向的大小之調整,在一譜線窄化雷射之情況下,如第14圖中的例子所示。如第15圖中所描述的,光束可在可調整孔徑之前被擴展以改良可控性,例如利用一擴束器612、一稜鏡或多數 個稜鏡、或者透鏡組合之一透鏡及類似者。在光束之一部分被可調整孔徑選擇之後,其(如以上所注明的)可被擴展/壓縮且準直以滿足PA或PO之光束大小要求(例如在該可調整光束擴展準直器內),這可以(舉例而言)是一望遠鏡或具有一獨立準直透鏡的可調整望遠鏡。光束擴展可能不需要用於一MOPO配置,其中在該等電極之間的放電期間的該等放大器電極之區域內的光束大小可以不與一(複數)固定通道放大器內的一樣重要。該等光束成形光學元件也可(舉例而言)是在兩個被調整的透鏡之間具有距離的圓柱透鏡之一組合。對於對稱頻譜控制,一可調整孔徑之中心可被調整到光束之中心。對於非對稱頻譜控制,可調整孔徑之中心可在一軸內移動(例如,在向著光束之一邊緣或另一邊緣的水平方向內)以(例如)增加或減少波長。An adjustable aperture may be rectangular to adjust within the short axis of the beam, which is generally horizontal in the applicant's transferee's laser system (eg, Cymer's 7XXX series or XLA or LXLR series laser systems) The adjustment of the direction of the direction is as shown in the example in Fig. 14 in the case where the line is narrowed by a laser. As described in Figure 15, the beam can be expanded to improve controllability prior to the adjustable aperture, such as with a beam expander 612, a chirp or a majority One lens, or one lens combination, and the like. After a portion of the beam is selected by the adjustable aperture, it (as noted above) can be expanded/compressed and collimated to meet the beam size requirements of the PA or PO (eg, within the adjustable beam expansion collimator) This can, for example, be a telescope or an adjustable telescope with an independent collimating lens. Beam spreading may not be required for a MOPO configuration where the beam size in the region of the amplifier electrodes during discharge between the electrodes may not be as important as in a (complex) fixed channel amplifier. The beam shaping optics may also be, for example, a combination of one of the cylindrical lenses having a distance between the two tuned lenses. For symmetric spectrum control, the center of an adjustable aperture can be adjusted to the center of the beam. For asymmetric spectral control, the center of the adjustable aperture can be moved within one axis (e.g., in a horizontal direction toward one edge or the other edge of the beam) to, for example, increase or decrease wavelength.
對於一雷射操作參數之某些干擾(例如,與光束品質相關,例如帶寬),變化較可能出現在光束之垂直方向內。作為重複率相依干擾之一例子,這可是真的。因此,第14圖中描述的可變孔徑可在所描述的頁面之平面內旋轉90°且選擇該光束之一垂直方向部分以供光束品質參數選擇(例如,帶寬選擇)。這也可利用第14圖中的一選擇孔徑串聯剛才描述的另一孔徑被執行。For some interference with a laser operating parameter (eg, related to beam quality, such as bandwidth), the change is more likely to occur in the vertical direction of the beam. As an example of repetition rate dependent interference, this is true. Thus, the variable aperture described in Figure 14 can be rotated 90° in the plane of the described page and one of the beam is selected for the beam quality parameter selection (e.g., bandwidth selection). This can also be performed using another aperture just described in connection with a selection aperture in Figure 14.
對於一些應用,該可變放大譜線窄化模組502可回應該帶寬測量模組516產生的信號。該可變放大譜線窄化模組502可被用於粗帶寬控制,利用帶寬控制可旋轉稜鏡520、522、524及/或526中的一者或兩者以及另一帶寬控制致動 器(例如差動發射時間(dtMOPA)或者光柵彎曲,例如利用在第7圖中的630中示意性顯示的一帶寬控制設備(“BCD”)光柵變形器),或者共振腔內或外的一可變孔徑可被用於細帶寬控制。該等帶寬選擇致動器中的每個可與其他致動器中的任何一者或多者結合使用,作為一粗控制致動器及一細控制致動器中的一者或另一者。For some applications, the variable amplification line narrowing module 502 can echo the signals generated by the bandwidth measurement module 516. The variable amplification line narrowing module 502 can be used for coarse bandwidth control, utilizing one or both of the bandwidth control rotatable ports 520, 522, 524, and/or 526 and another bandwidth control actuation (e.g., differential emission time (dtMOPA) or grating bending, such as a bandwidth control device ("BCD") grating deformer) schematically shown in 630 in Figure 7, or one inside or outside the resonant cavity Variable aperture can be used for fine bandwidth control. Each of the bandwidth selective actuators can be used in conjunction with any one or more of the other actuators as one or the other of a coarse control actuator and a fine control actuator .
該項領域內具有通常知識者將明白的是,以上所揭露的標的之實施例的層面意指滿足揭露每個申請專利範圍之標的之至少一致能實施例之要求且只是一或多個此等示範性實施例且不以任何方式限制任何申請專利範圍之範圍且不特定於一特定個別揭露的實施例。該項領域內具有通常知識者將明白且瞭解的是,可對申請專利範圍之所揭露的標的之實施例之被揭露的層面作出許多變化及修改,特別是關於解釋申請專利範圍以供等效物之說明。附加的申請專利範圍在本範圍及含義內意指不僅涵蓋所主張的標的之實施例之被揭露的層面,而且此等等效及其他修改及變化是該項領域內具有通常知識者顯而易見的。除了以上所注明的本發明之被揭露的標的之被揭露且主張的層面之變化及修改之外,其他變化及修改可被實施。It will be apparent to those skilled in the art that the above-described embodiments of the subject matter disclosed above are intended to satisfy the requirements of at least the consistent embodiments of the subject matter of the disclosure. The exemplary embodiments are not intended to limit the scope of any claims, and are not intended to It will be apparent to those skilled in the art that many changes and modifications can be made to the disclosed aspects of the disclosed embodiments of the subject matter disclosed herein. Description of the object. The scope of the appended claims is intended to cover the scope of the embodiments of the claimed subject matter, and such equivalents and other modifications and variations are apparent to those of ordinary skill in the art. Other variations and modifications can be implemented in addition to the above-described changes and modifications of the disclosed subject matter disclosed herein.
80‧‧‧干擾80‧‧‧Interference
82‧‧‧細致動範圍82‧‧‧fine actuation range
84‧‧‧粗致動範圍84‧‧‧Rough actuation range
158‧‧‧可調整孔徑158‧‧‧Adjustable aperture
200‧‧‧雷射系統控制器200‧‧‧Laser System Controller
202‧‧‧FCP202‧‧‧FCP
204‧‧‧FCC204‧‧‧FCC
206‧‧‧LCP206‧‧‧LCP
210‧‧‧BAM210‧‧‧BAM
212‧‧‧LAM212‧‧‧LAM
220‧‧‧帶寬控制模組220‧‧‧Bandwidth Control Module
222‧‧‧可變放大譜線窄化模組222‧‧‧Variable amplification line narrowing module
232‧‧‧步階命令232‧‧ ‧ step order
234‧‧‧加法器234‧‧‧Adder
236‧‧‧樣本延遲236‧‧‧ sample delay
240‧‧‧干擾方塊240‧‧‧Interference block
242‧‧‧加法器242‧‧‧Adder
244‧‧‧樣本延遲方塊244‧‧‧sample delay block
246‧‧‧加法器246‧‧‧Adder
247‧‧‧雜訊方塊247‧‧‧ Noise Block
248‧‧‧常數方塊248‧‧‧ Constant Square
249‧‧‧輸出249‧‧‧ Output
250‧‧‧帶寬控制器250‧‧‧ Bandwidth Controller
252‧‧‧帶寬目標252‧‧‧Bandwidth target
254‧‧‧被量測的帶寬254‧‧‧Measured bandwidth
256‧‧‧波長TIR256‧‧‧wavelength TIR
257‧‧‧處理器257‧‧‧ Processor
258‧‧‧加法器258‧‧‧Adder
260‧‧‧雜訊濾波器260‧‧‧ noise filter
262‧‧‧不感帶磁滯控制方塊262‧‧‧Do not feel hysteresis control block
264‧‧‧控制模式選擇器264‧‧‧Control mode selector
266‧‧‧正負號方塊266‧‧‧ plus and minus squares
268‧‧‧目標變化檢測器268‧‧‧Target change detector
270‧‧‧乘法器270‧‧‧ Multiplier
272‧‧‧控制增益放大器272‧‧‧Control Gain Amplifier
274‧‧‧命令飽和方塊274‧‧‧Command saturated block
276‧‧‧步階平滑器276‧‧‧step smoother
278‧‧‧目標變化迴旋步進放大器278‧‧‧Target change cyclotron stepper amplifier
280‧‧‧三極開關280‧‧‧ three-pole switch
284‧‧‧步階命令284‧‧ ‧ step order
290‧‧‧輸入290‧‧‧Enter
292‧‧‧絕對值函數方塊292‧‧‧Absolute value function block
294‧‧‧轉發方塊294‧‧‧ Forwarding Block
296‧‧‧輸出296‧‧‧ output
340‧‧‧除法器340‧‧‧ divider
342‧‧‧加法器342‧‧‧Adder
344‧‧‧樣本延遲344‧‧‧sample delay
346‧‧‧乘法器方塊346‧‧‧Multiplier Block
348‧‧‧加法器348‧‧‧Adder
350‧‧‧含入方塊350‧‧‧Into the box
352‧‧‧方塊352‧‧‧
354‧‧‧絕對值方塊354‧‧‧Absolute value box
356‧‧‧乘法器方塊356‧‧‧Multiplier Block
358‧‧‧加法器358‧‧‧Adder
360‧‧‧截取方塊360‧‧‧ interception block
364‧‧‧加法器364‧‧‧Adder
366‧‧‧樣本延遲方塊366‧‧‧sample delay block
368‧‧‧延遲方塊368‧‧‧ Delay Block
370‧‧‧加法器370‧‧‧Adder
500‧‧‧多級氣體放電雷射500‧‧‧Multi-level gas discharge laser
502‧‧‧可變放大譜線窄化模組502‧‧‧Variable amplification line narrowing module
504‧‧‧第一級腔室504‧‧‧First stage chamber
506‧‧‧第一級輸出耦接器506‧‧‧First Stage Output Coupler
508a‧‧‧轉向光學元件508a‧‧‧steering optics
508b‧‧‧轉向光學元件508b‧‧‧Steeling optics
510‧‧‧輸入耦接器510‧‧‧Input Coupler
512‧‧‧第二級腔室512‧‧‧Second stage chamber
514‧‧‧分束器514‧‧‧beam splitter
516‧‧‧帶寬測量模組516‧‧‧Bandwidth Measurement Module
518‧‧‧放電時序控制模組518‧‧‧Discharge timing control module
520‧‧‧稜鏡520‧‧‧稜鏡
522‧‧‧稜鏡522‧‧‧稜鏡
524‧‧‧稜鏡524‧‧‧稜鏡
526‧‧‧稜鏡526‧‧‧稜鏡
528‧‧‧光柵528‧‧‧Raster
540‧‧‧RMAX 反射鏡540‧‧‧R MAX mirror
600‧‧‧可調整光束擴展準直器600‧‧‧Adjustable Beam Expanding Collimator
610’‧‧‧可調整孔徑610'‧‧‧Adjustable aperture
612‧‧‧擴束器612‧‧‧beam expander
620‧‧‧帶寬控制器620‧‧‧ Bandwidth Controller
630‧‧‧帶寬控制設備630‧‧‧ Bandwidth Control Equipment
第1圖顯示了一帶寬控制設備E95 敏感度曲線;第2圖描述了依據被揭露的標的之一實施例之層面的干擾類型與時標及幅值;第3圖示意性且以方塊圖形式顯示了依據被揭露的標 的之一實施例之層面的具有一可變放大譜線窄化模組及差動發射時間(dtMOPA)帶寬控制的一多級氣體放電雷射系統;第4圖示意性且以方塊圖形式顯示了依據被揭露的標的之一實施例之層面的具有4個稜鏡及一光柵的一實施例,其中至少一稜鏡可被旋轉以增加/減少光束寬度,從而改變帶寬;第5圖描述了可用於被揭露的標的之一實施例之層面的一雷射控制系統整體架構;第6圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面控制的一代表性雷射系統“植入”;第7圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的一帶寬控制器;第8圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的一擊發平滑器;第9圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的一不感帶磁滯方塊;第10圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的一控制模式選擇器;第11圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的具有複數稜鏡及一中心波長選擇反射鏡的一實施例;第12圖描述了一使用△tMOPA 的E95 帶寬控制中心;第13圖示意性地描述了依據被揭露的標的之一實施例之層面的一可變放大LNM; 第14圖示意性且以方塊圖形式描述了依據被揭露的標的之一實施例之層面的一可調整孔徑帶寬控制致動器(控制中心);第15圖示意性地且以方塊圖形式顯示了依據被揭露的標的之一實施例之層面的一帶寬控制系統;以及第16圖示意與光束經過的孔徑之大小相依的帶寬變化之例子。Figure 1 shows a bandwidth control device E 95 sensitivity curve; Figure 2 depicts the interference type and time scale and amplitude of the layer according to one embodiment of the disclosed subject matter; Figure 3 is schematic and block The diagram shows a multi-stage gas discharge laser system with a variable amplification line narrowing module and differential emission time (dtMOPA) bandwidth control in accordance with one embodiment of the disclosed subject matter; Figure 4 Illustratively and in block diagram form an embodiment having four turns and a grating in accordance with a layer of one embodiment of the disclosed subject matter, wherein at least one turn can be rotated to increase/decrease the beam width, Thereby changing the bandwidth; Figure 5 depicts the overall architecture of a laser control system that can be used at the level of one of the disclosed embodiments; Figure 6 is a schematic and block diagram depicting one of the disclosed targets A representative laser system of the embodiment controls "implantation"; Figure 7 schematically and in block diagram form a bandwidth controller in accordance with one aspect of the disclosed embodiment; Figure 8 Schematic and block diagram The form describes a firing smoother in accordance with the level of one embodiment of the disclosed subject matter; FIG. 9 is a schematic and block diagram depicting a non-inductive hysteresis in accordance with the level of one embodiment of the disclosed subject matter. Figure 10 is a schematic and block diagram depicting a control mode selector in accordance with the level of one embodiment of the disclosed subject matter; Figure 11 is schematically and in block diagram depicting the disclosure according to the disclosure Example of a level having a plurality of Example Prism and a central wavelength selective mirror subject to one embodiment; FIG. 12 E 95 describes the use of a bandwidth control center of △ t MOPA; FIG. 13 schematically depicts the A variable amplification LNM according to a level of an embodiment of the disclosed subject matter; Figure 14 is a schematic and block diagram depicting an adjustable aperture bandwidth control in accordance with a level of an embodiment of the disclosed subject matter Actuator (control center); Figure 15 shows schematically and in block diagram form a bandwidth control system in accordance with the level of one of the disclosed embodiments; and Figure 16 illustrates the aperture through which the beam passes. size Examples of dependent bandwidth changes.
250‧‧‧帶寬控制器250‧‧‧ Bandwidth Controller
252‧‧‧帶寬目標252‧‧‧Bandwidth target
254‧‧‧被量測的帶寬254‧‧‧Measured bandwidth
256‧‧‧波長TIR256‧‧‧wavelength TIR
257‧‧‧處理器257‧‧‧ Processor
258‧‧‧加法器258‧‧‧Adder
260‧‧‧雜訊濾波器260‧‧‧ noise filter
262‧‧‧不感帶磁滯控制方塊262‧‧‧Do not feel hysteresis control block
264‧‧‧控制模式選擇器264‧‧‧Control mode selector
266‧‧‧正負號方塊266‧‧‧ plus and minus squares
268‧‧‧目標變化檢測器268‧‧‧Target change detector
270‧‧‧乘法器270‧‧‧ Multiplier
272‧‧‧控制增益放大器272‧‧‧Control Gain Amplifier
274‧‧‧命令飽和方塊274‧‧‧Command saturated block
276‧‧‧步階平滑器276‧‧‧step smoother
278‧‧‧目標變化迴旋步進放大器278‧‧‧Target change cyclotron stepper amplifier
280‧‧‧三極開關280‧‧‧ three-pole switch
284‧‧‧步階命令284‧‧ ‧ step order
Claims (66)
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US92348607P | 2007-04-13 | 2007-04-13 | |
US12/082,254 US7894494B2 (en) | 2007-04-13 | 2008-04-09 | Method and apparatus to control output spectrum bandwidth of MOPO or MOPA laser |
US12/082,301 US7899095B2 (en) | 2007-04-13 | 2008-04-09 | Laser lithography system with improved bandwidth control |
US12/082,253 US7822084B2 (en) | 2006-02-17 | 2008-04-09 | Method and apparatus for stabilizing and tuning the bandwidth of laser light |
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US8837536B2 (en) * | 2010-04-07 | 2014-09-16 | Cymer, Llc | Method and apparatus for controlling light bandwidth |
US9606519B2 (en) * | 2013-10-14 | 2017-03-28 | Applied Materials, Inc. | Matching process controllers for improved matching of process |
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US20020085606A1 (en) * | 1999-09-27 | 2002-07-04 | Ness Richard M. | Injection seeded laser with precise timing control |
US6490306B2 (en) * | 1999-02-10 | 2002-12-03 | Lambda Physik Ag | Molecular fluorine laser with spectral linewidth of less than 1 pm |
JP2004311766A (en) * | 2003-04-08 | 2004-11-04 | Ushio Inc | Two-stage laser device for exposure |
JP2006024855A (en) * | 2004-07-09 | 2006-01-26 | Komatsu Ltd | Narrow-band laser apparatus |
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US6490306B2 (en) * | 1999-02-10 | 2002-12-03 | Lambda Physik Ag | Molecular fluorine laser with spectral linewidth of less than 1 pm |
US20020085606A1 (en) * | 1999-09-27 | 2002-07-04 | Ness Richard M. | Injection seeded laser with precise timing control |
JP2004311766A (en) * | 2003-04-08 | 2004-11-04 | Ushio Inc | Two-stage laser device for exposure |
JP2006024855A (en) * | 2004-07-09 | 2006-01-26 | Komatsu Ltd | Narrow-band laser apparatus |
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