JPS6198314A - Automatic focusing mechanism - Google Patents

Automatic focusing mechanism

Info

Publication number
JPS6198314A
JPS6198314A JP59218571A JP21857184A JPS6198314A JP S6198314 A JPS6198314 A JP S6198314A JP 59218571 A JP59218571 A JP 59218571A JP 21857184 A JP21857184 A JP 21857184A JP S6198314 A JPS6198314 A JP S6198314A
Authority
JP
Japan
Prior art keywords
focus
sensor
air
focusing
wafer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP59218571A
Other languages
Japanese (ja)
Inventor
Masakatsu Oota
太田　正克
Shuichi Yabu
藪　修一
Junichi Murakami
潤一 村上
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Priority to JP59218571A priority Critical patent/JPS6198314A/en
Priority to DE19843447488 priority patent/DE3447488A1/en
Priority to FR848419987A priority patent/FR2572197B1/en
Priority to GB8432820A priority patent/GB2166879B/en
Publication of JPS6198314A publication Critical patent/JPS6198314A/en
Priority to US07/220,440 priority patent/US4998821A/en
Priority to FR888816238A priority patent/FR2623304B1/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70216—Mask projection systems
    • G03F7/70241—Optical aspects of refractive lens systems, i.e. comprising only refractive elements
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70216—Mask projection systems
    • G03F7/70258—Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70691—Handling of masks or workpieces
    • G03F7/70716—Stages
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
    • G03F7/70858—Environment aspects, e.g. pressure of beam-path gas, temperature
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
    • G03F7/70858—Environment aspects, e.g. pressure of beam-path gas, temperature
    • G03F7/70866—Environment aspects, e.g. pressure of beam-path gas, temperature of mask or workpiece
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
    • G03F7/70858—Environment aspects, e.g. pressure of beam-path gas, temperature
    • G03F7/70866—Environment aspects, e.g. pressure of beam-path gas, temperature of mask or workpiece
    • G03F7/70875—Temperature, e.g. temperature control of masks or workpieces via control of stage temperature
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
    • G03F7/70858—Environment aspects, e.g. pressure of beam-path gas, temperature
    • G03F7/70883—Environment aspects, e.g. pressure of beam-path gas, temperature of optical system
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
    • G03F7/70858—Environment aspects, e.g. pressure of beam-path gas, temperature
    • G03F7/70883—Environment aspects, e.g. pressure of beam-path gas, temperature of optical system
    • G03F7/70891—Temperature

Landscapes

  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Atmospheric Sciences (AREA)
  • Toxicology (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Epidemiology (AREA)
  • Public Health (AREA)
  • Automatic Focus Adjustment (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

Abstract

PURPOSE:To compensate focus variation due to environmental variation without a printing test by moving a reference surface for focusing in the optical axis direction on the basis of an output of a sensor means for detecting the environmental conditions of a pattern transfer device. CONSTITUTION:An offset compensating function part of an automatic focusing means is constituted so that the outputs of an atmospheric pressure sensor 31, a temperature sensor 32, a humidity sensor 33, and a focus detector 34 are inputted to a microprocessor 35, and after executing operation, the miroprocessor 35 calculates a distance from the original point of the coordinates of an air sensor to a wafer surface and inputs the moving distance of a Z axis to a Z axis driver 36. An offset value for indicating the reference position of focusing is set up in an air sensor. The offset value is set up so that a best focusing position found by a printing test is the reference focusing position. When a fixed offset value is determined, an automatic focusing function part moves an wafer in the optical axis (Z axis) direction by the device 36 so that an offset reading value is set up to a required value on the basis of the output of the air sensor 34.

Description

【発明の詳細な説明】 ［発明の属する分野］ 本発明は、気圧等の環境条件に応じてピント位置を自動
的に補正するようにしたオートフォーカス機構に関する
。この機構は、例えばＩＣパターン焼付転写装置、特に
投影光学系を用いてマスクパターンをウェハに転写する
プロジェクション方式の焼付装置に適用して好適なもの
である。DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an autofocus mechanism that automatically corrects a focus position according to environmental conditions such as atmospheric pressure. This mechanism is suitable for application to, for example, an IC pattern printing and transfer apparatus, particularly a projection type printing apparatus that uses a projection optical system to transfer a mask pattern onto a wafer.

［従来技術の説明］ プロジェクション方式の焼付装置とは、原板上に形成さ
れたパターン像（例えばレチクル上に描かれているＩＣ
パターン）を投影光学系により感光体（例えば感光剤を
塗布しであるウェハ）に転写するものであり、その解像
線幅は投影光学系の明るさく以下ＦＮＯと称す）によっ
て決定される。[Description of Prior Art] A projection type printing device is a printing device that prints a pattern image formed on an original plate (for example, an IC drawn on a reticle).
A projection optical system transfers a pattern (pattern) onto a photoreceptor (for example, a wafer coated with a photosensitive agent), and the resolution line width is determined by the brightness (hereinafter referred to as FNO) of the projection optical system.

近年、ＩＣパターンの微細化が進み、Ｉｃパターン焼付
転写装置も従来のコンタクト方式やプロキシミティ方式
からプロジェクション方式へと進み、プロジェクション
方式の中でもミラー投影光学系からＦＮＯの明るい（Ｆ
ＮＯ値の小さい）レンズ投影光学系に変りつつある。In recent years, as IC patterns have become finer, IC pattern printing and transfer equipment has also progressed from the conventional contact and proximity methods to projection methods.
There is a shift toward lens projection optical systems (with small NO values).

通常、プロジェクション方式の限界解像力（Ｌ）および
焦点深度（Ｄ）は、λを焼付波長としてＬ＝１，６λＦ
ＮＯ Ｄ＝±λＦＮ、Ｏ’　　　（λ／８基準）で与えられる
が、上式かられかる通り解像力を上げるためには波長を
短くするか、ＦＮＯ値を小さくしなければならず、解像
力を上げると焦点深度が浅くなってしまう。Normally, the critical resolution (L) and depth of focus (D) of the projection method are L=1.6λF, where λ is the printing wavelength.
NO D = ±λFN, O' (based on λ/8), but as shown in the above equation, in order to increase the resolution, the wavelength must be shortened or the FNO value must be decreased, which increases the resolution. The depth of focus becomes shallow.

例えば、現在ステッパと呼ばれるプロジエクシ（°＞”
：０Ｉ０”１１°“＊Ｍａ！！！＆ＬｙＴＧｌ”　　　
　　　（４３６ｎｍ）を用い、ＦＮＯは　１．４３が主
流とな１′ っているが、この時の焦点深度は±０．９μｍに過ぎな
い。この僅かな焦点深度内にウェハを配置させるために
種々のオートフォーカス方式が考え出されており、精度
も±０．１μｍ〜±　０．５μｍと高い精度を有してい
る。For example, the projiexi (°＞”
:0I0"11°"*Ma! ! ! &LyTGl”
(436 nm) and FNO of 1.43 is the mainstream, but the depth of focus at this time is only ±0.9 μm. Various autofocus methods have been devised to place the wafer within this small depth of focus, and the accuracy is as high as ±0.1 μm to ±0.5 μm.

しかしながら、現在のオートフォーカス方式は、投影光
学系の鏡筒の端面からある距離に基準面を設定し、この
基準面からウェハ表面までの距離を一定に保つためのも
のがほとんどで、投影光学系のピント位置くピント基準
面）が一定の時には極めて高い精度でウェハ表面をピン
ト位置に配置することができるが、何らかの影響でピン
ト位置が変化するとウェハ表面をピント面に配置するこ
とができなくなってしまう。However, most current autofocus systems set a reference plane at a certain distance from the end face of the lens barrel of the projection optical system, and maintain a constant distance from this reference plane to the wafer surface. When the focus position (focus reference plane) is constant, it is possible to place the wafer surface at the focus position with extremely high accuracy, but if the focus position changes for some reason, the wafer surface cannot be placed at the focus plane. Put it away.

投影光学系のピント位置を変える要因として考えられる
ものは■レチクルとウェハとの間の空気の温度変化およ
び投影光学系中の硝材の温度変化、■レチクルとウェハ
との間の空気の大気圧、および■レチクルとウェハとの
間の空気の湿度等である。　　　　　　　　　　　　　
　　　　　　　　　　　１■の空気および硝材の温度変
化に対して投影光学系構成要素の中で変わり得るものは
レンズ面の曲率半径、レンズ面間の間隔、および空気と
硝子の相対屈折率であり、これ等の構成要素の変化によ
り投影光学系のピント位置は変わる。このような温度変
化によるピント位置の変化は、係数的には、上記３つの
要因の中で最も大きい。従来は、ニアコンディショニン
グ等の手段により装置の環境および装置内の温度を制御
してピント位置の変化量を抑えていた。Factors that can be considered to change the focus position of the projection optical system are ■ changes in the temperature of the air between the reticle and the wafer and changes in the temperature of the glass material in the projection optical system, ■ atmospheric pressure of the air between the reticle and the wafer, and (2) the humidity of the air between the reticle and the wafer.
Among the components of the projection optical system that can change due to the temperature change of the air and glass material described in 1. The focus position of the projection optical system changes as the components change. The change in focus position due to such a temperature change is coefficient-wise the largest among the above three factors. Conventionally, the amount of change in the focus position has been suppressed by controlling the environment of the device and the temperature inside the device by means such as near conditioning.

一方、■の空気の大気圧および■の空気の湿度の変化に
対しては、ジエー・シー・オーエンス（Ｊ、　Ｃ，Ｏｗ
ｅｎｓ）が詳しく研究しアブライドオブヂックス　１９
６７年　第１号（ＡＰＰＬｉＥＤＯＰＴ　Ｉ　Ｃ８１９
６７Ｎｏ、１）に発表しているように、空気の大気圧ま
たは湿度が変化すると空気の屈折率が変化することが知
られている―この場合、硝材の屈折率は実質的に変化し
てないから屈折面での相対屈折率が変化することになる
。On the other hand, for changes in the atmospheric pressure of the air (■) and the humidity of the air (■),
ens) has conducted detailed research on Abride Obedix 19
1967 No. 1 (APPLiEDOPT I C819
As published in 67 No. 1), it is known that the refractive index of the air changes when the atmospheric pressure or humidity of the air changes - in this case, the refractive index of the glass material does not substantially change. The relative refractive index at the refractive surface changes from .

空気の絶対屈折率をｎＡ、１１１子の絶対屈折率をｎＧ
、硝子と空気の相対屈折率をｎとするとｎ　＝　ｎ　ｃ
　／　ｎ　Ａ　　　− で与えられ、ｎＡがΔｎＡ変化するとｎの変化ωΔｎは
ｎＡキ゛１より Δｎ−＝ｎ（、・ΔｎＡ によって与えられる。通常、ｎ（、は約１．５であるか
ら、 Δｎ＝１．５ΔｎＡ となり、空気の屈折率変化が硝子と空気の相対屈折率変
化に与える影響は空気の屈折率変化自身の１．５倍の量
となる。例えば大気圧が５ｍｍＨｇ変化すると空気の屈
折率は約ｉ、ａｘ　ｉｏ　　変化するが、これは硝子と
空気の相対屈折率の２，７Ｘ　１０　　に相当し、投影
光学系の個々の性質により変ってくるが、ピント変化と
しては０．５〜１．５μｍに相当する。この値は前述の
焦点深度の値が±０．９μｍであることからもわかるよ
うに装置の性能上、充分問題となる変化量である。The absolute refractive index of air is nA, and the absolute refractive index of 111 particles is nG.
, where n is the relative refractive index of glass and air, n = n c
/ n A − , and when nA changes by ΔnA, the change in n ωΔn is given by Δn−=n(,・ΔnA from nA key 1. Normally, n(, is about 1.5, so Δn= 1.5ΔnA, and the effect that the change in the refractive index of air has on the relative refractive index change between glass and air is 1.5 times the change in the refractive index of the air itself.For example, if the atmospheric pressure changes by 5 mmHg, the refractive index of air will change. changes by approximately i, ax io, which corresponds to the relative refractive index of glass and air of 2.7X 10, and varies depending on the individual properties of the projection optical system, but the focus change is 0.5 to 1. This value corresponds to .5 μm.As can be seen from the above-mentioned depth of focus value of ±0.9 μm, this value is a sufficient amount of change to cause problems in terms of the performance of the apparatus.

以上のようにプロジェクション方式の焼付装置において
、外的環境（温度、気圧、湿度等）の変化によりピント
変化が生じるが、従来は３日に１回程度の焼付テストを
行なうことでピント変化を補正していた。As mentioned above, in projection printing devices, changes in focus occur due to changes in the external environment (temperature, atmospheric pressure, humidity, etc.), but conventionally, focus changes are corrected by performing a printing test about once every three days. Was.

［発明の目的］ 本発明の目的は、投影光学系から感光体表面までの距離
を所定値に調整するいわゆる一定距離方式のオートフォ
ーカス機構において、投影光学系のピント変化を自動的
に補正することであり、それによって、環境変化による
ピント変化を焼付テストすることなしに補正することを
可能とすることである。[Object of the Invention] An object of the present invention is to automatically correct changes in focus of the projection optical system in a so-called constant distance autofocus mechanism that adjusts the distance from the projection optical system to the surface of the photoreceptor to a predetermined value. By doing so, it is possible to correct changes in focus due to environmental changes without performing a burn-in test.

なお、上述の温度変化は、外的環境によるものの他、焼
付光による投影光学系の温度上昇や投影光学系を含む装
置の発熱による温度上昇によっても発生し、装置の動作
開始初期等の過渡状態で特に問題となるが、本出願人は
、投影光学系の温度変化によるピント位置の変化を自動
的に補正するため、温度対ピント位置の関係を予めメモ
リに記１　　　憶させるとともに、投影光学系の温度を
検知し、：：ｉ　　　その温度に対応するピント位置を
メモリから読出してピント位置を補正するようにした露
光装置を先に提案している（特願昭５８−２３０５７８
号）。本発明は、投影光学系の温度変化を直接検知する
のではなく、温度をも含む外的環境条件を検知する点に
おいて上記先願とは異なるものである。In addition to being caused by the external environment, the temperature change described above also occurs due to a temperature increase in the projection optical system due to burning light or a temperature increase due to heat generation in the device including the projection optical system, and may occur during transient conditions such as when the device starts operating. However, in order to automatically correct changes in the focus position due to changes in the temperature of the projection optical system, the applicant stores the relationship between temperature and focus position in advance in memory, and the projection optical system He previously proposed an exposure device that detects the temperature of ::i, reads out the focus position corresponding to that temperature from memory, and corrects the focus position (Japanese Patent Application No. 58-230578).
issue). The present invention differs from the above-described prior application in that it does not directly detect temperature changes in the projection optical system, but instead detects external environmental conditions including temperature.

［実施例の説明］ 以下、図面を用いて本発明の詳細な説明する。[Explanation of Examples] Hereinafter, the present invention will be explained in detail using the drawings.

第１図は、本発明の一実施例に係るオーフォーカス機構
を適用した焼付装置の光学系部分の断面を示す。同図に
おいて、１はレチクル、２は投影光学系、３はオートフ
ォーカス機構である。同図ではオートフォーカス機構３
のフォーカス検出器（第２図の３４）としてエアーセン
サを用いており、４はエアーセンサのノズル端面、５は
ウェハ、６はエアーセンサの座標原点を示している。FIG. 1 shows a cross section of an optical system portion of a printing apparatus to which an autofocus mechanism according to an embodiment of the present invention is applied. In the figure, 1 is a reticle, 2 is a projection optical system, and 3 is an autofocus mechanism. In the figure, autofocus mechanism 3
An air sensor is used as the focus detector (34 in FIG. 2), 4 is the nozzle end face of the air sensor, 5 is the wafer, and 6 is the coordinate origin of the air sensor.

第２図は、第１図のオートフォーカス機構３のオフセッ
ト補正機能部のブロック図で、気圧センサ３１、温度セ
ンサ３２、湿度センサ３３およびフォーカス検出器３４
の出力をマイクロプロセッサ３５に入幕 力し、マイクロプロセッサ３５で後述の演算を実行　　
　　１後、エアーセンサ座標原点６からウェハ５面まで
の距離を計算し、Ｚ軸駆動装置３６にＺ軸移動但を入力
するように構成されている。FIG. 2 is a block diagram of the offset correction function section of the autofocus mechanism 3 shown in FIG.
The output is inputted to the microprocessor 35, and the microprocessor 35 executes the calculations described below.
1, the distance from the air sensor coordinate origin 6 to the surface of the wafer 5 is calculated, and the Z-axis movement distance is input to the Z-axis drive device 36.

次に、第１図および第２図を用い、本発明の詳細な説明
する。レチクル１を通過、回折した光は、投影光学系２
によりウェハ５面上にレチクルパターンを結像する。エ
アーセンサ３４はエアーノズル４から吹き出される空気
の背圧を感知し、エアーセンサ座標原点６からウェハ５
面までの距離を電気的処理により求める（以下、この距
離計測値をオフセットリード値と称する）。一方、エア
ーセンサには、ピント基準位置を示すオフセット値が設
定されている。通常、このオフセット値は、焼付テス１
〜を行なうことにより求まるベストピント位置がピント
基準位置となるように設定される。Next, the present invention will be explained in detail using FIGS. 1 and 2. The light that passes through the reticle 1 and is diffracted is transmitted to the projection optical system 2.
A reticle pattern is imaged on the 5 surface of the wafer. The air sensor 34 senses the back pressure of the air blown out from the air nozzle 4, and moves the air sensor 34 from the air sensor coordinate origin 6 to the wafer 5.
The distance to the surface is determined by electrical processing (hereinafter, this distance measurement value is referred to as an offset read value). On the other hand, an offset value indicating a focus reference position is set in the air sensor. Typically, this offset value is
The best focus position found by performing . . . is set as the focus reference position.

一定のオフセット値が決まると、第２図のオートフォー
カス機能部は、エアーセンサ３４の出力をもとにオフセ
ットリード値が所望の値になるように２＠駆動装置３６
を用いてウェハ５を光軸（２軸）方向に移動させる。投
影光学系２のピント位置が一定の場合には上記のオート
フォーカス機能によりウェハ５面は投影光学系２のピン
ト位置に保つことができる。しかしながら、前記の如く
温度、気圧、湿度が変わると投影光学系２のピント位置
が変化するのでオフセット値が一定に保たれてもウェハ
５面と投影光学系２のピント面とが一致しなくなる。Once a certain offset value is determined, the autofocus function section shown in FIG.
The wafer 5 is moved in the direction of the optical axis (two axes). When the focus position of the projection optical system 2 is constant, the wafer 5 surface can be maintained at the focus position of the projection optical system 2 by the above autofocus function. However, as mentioned above, when the temperature, air pressure, and humidity change, the focus position of the projection optical system 2 changes, so even if the offset value is kept constant, the surface of the wafer 5 and the focus plane of the projection optical system 2 do not match.

本発明では、装置上に気圧センサ３１、温度センサ３２
および湿度センサ３３を配置し、気圧、温度および湿度
の変化量を感知してマイクロプロセッサ３５によりピン
ト位置の変化量を計算する。ピント位置の変化量ΔＳは
、ΔＳｐ、ΔＳＴ、　ΔＳｖを各々気圧、温度および湿
度によるピント位置の変化量として ΔＳ＝ΔＳＰ＋ΔＳＴ十ΔＳｖ ΔＳｐ　＝Ａ・ΔＰ ΔＳｙ　＝Ｂ・２丁 ΔＳｖ　＝Ｃ・ΔＶ により計算する。ここで、ΔＰ、ΔＴ、ΔＶは各々気圧
、温度ｉ！Ｉｉ１度の変化量、Ａ、Ｂ、　Ｃは定数であ
る。定数Ａ、Ｂ、Ｃは計算により求めても良いが、実験
で求めるのがより実際的である。また、上式ではΔＰ、
ΔＴ、ΔＶの１次式によりΔＳを求めるようにしている
。理論的には高次の項の影響も考えられるが、ΔＰ、Δ
Ｔ、ΔＶの値が実際には小さいので、１次式で充分であ
る。In the present invention, an air pressure sensor 31 and a temperature sensor 32 are provided on the device.
A humidity sensor 33 is arranged to sense changes in atmospheric pressure, temperature, and humidity, and a microprocessor 35 calculates the amount of change in the focus position. The amount of change in the focus position ΔS is calculated as follows, where ΔSp, ΔST, and ΔSv are the amount of change in the focus position due to atmospheric pressure, temperature, and humidity, respectively. do. Here, ΔP, ΔT, and ΔV are atmospheric pressure and temperature i!, respectively. Ii1 degree change, A, B, and C are constants. Although the constants A, B, and C may be determined by calculation, it is more practical to determine them by experiment. Also, in the above formula, ΔP,
ΔS is determined by a linear equation of ΔT and ΔV. Theoretically, the influence of higher-order terms can be considered, but ΔP, Δ
Since the values of T and ΔV are actually small, a linear equation is sufficient.

マイクロプロセッサ３５は、計口されたピント位置変化
發を補正するようにオフセット値を求め、オフセットリ
ード値が上記オフセット値になるようにＺ軸駆動装置３
６でウェハ５を２軸方向へ移動する。フォーカス検出器
３４はオフセットリード値を検知し、マイクロプロセッ
サ３５に入力する。マイクロプロセッサ３５はオフセッ
トリード値とオフセット値を比較し、差が許容量以上で
あればＺ軸駆動装置３６でウェハ５を再び移動し、以下
、同様の操作を繰返す。The microprocessor 35 calculates an offset value to correct the measured focus position change, and controls the Z-axis drive device 3 so that the offset read value becomes the offset value.
6, the wafer 5 is moved in two axial directions. Focus detector 34 detects the offset read value and inputs it to microprocessor 35. The microprocessor 35 compares the offset read value and the offset value, and if the difference is greater than the allowable amount, the Z-axis drive device 36 moves the wafer 5 again, and the same operation is repeated thereafter.

［実施例の変形例］ なお、本発明は前述の実施例に限定されること１　　　
　　なく適宜変形して実施することができる。例えば、
ｊ　　　　　前記実施例ではウェハ面の上下位置検出装
置としてエアーセンサを用いているが、これは非接触式
電気マイクロメータを用いてもよく、あるいは、レーザ
光の走査またはテレビの映像処理による方法等光学的な
検出方法を用いた装置でもよい。また、前記実施例では
所定の演算式を用いてピント位置またはピント位置補正
發を求めるようにしているが、気圧、温度、湿度等の環
境条件に対応するピント位置を予めメモリに記憶させて
おき、環境条件情報を用いてピント位置を読み出すよう
にしてもよい。[Modifications of Examples] Note that the present invention is limited to the above-mentioned Examples.
It can be implemented with appropriate modifications. for example,
j In the above embodiment, an air sensor is used as a device for detecting the vertical position of the wafer surface, but a non-contact electric micrometer may be used for this, or an optical method such as a method using laser beam scanning or television image processing may be used. A device using a conventional detection method may also be used. Furthermore, in the embodiment described above, a predetermined calculation formula is used to determine the focus position or focus position correction, but the focus position corresponding to environmental conditions such as atmospheric pressure, temperature, humidity, etc. is stored in memory in advance. , the focus position may be read using environmental condition information.

また、上述においては、本発明を半導体焼付装置に適用
する場合について説明しているが、本発明は、ホログラ
ム作成装置や複写機等、他のパターン転写装置に対して
も適用することができることは勿論である。Further, in the above description, the case where the present invention is applied to a semiconductor printing device is explained, but the present invention can also be applied to other pattern transfer devices such as a hologram creation device and a copying machine. Of course.

［発明の効果］ 以上のごとく、本発明によれば、大気圧、温度または湿
度の変化に応じてウェハ表面等のパターン転写面の設定
位置を補正するようにしたため１、、、オニ、□よえ、
よ□（７）　！　（ｔ：、ｌ、ｍ力、ヵ、わ、ア、オ　
　ｊにパターン転写面を投影光学系のピント面に合致さ
せることができる。[Effects of the Invention] As described above, according to the present invention, the set position of the pattern transfer surface such as the wafer surface is corrected according to changes in atmospheric pressure, temperature, or humidity. picture,
Yo□(7)! (t:, l, m force, ka, wa, a, o
j, the pattern transfer surface can be made to match the focal plane of the projection optical system.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は、本発明の一実施例に係るオートフォーカス機
構を適用した焼付装置の光学系部分の断面図、 第２図は、第１図におけるオートフォーカス機構のオフ
セット補正機能部のブロック図である。 １ニレチクル、２：投影光学系、３：オートフォーカス
機構、４：エアーノズル端面、５：ウェハ、６：エアー
センサ座標原点、３１：気圧センサ、３２：温度センサ
、３３：湿度センサ、３４：フォーカス検出器（エアー
センサ）、３５：マイクロプロセッサ、３６：Ｚ軸駆動
装置。FIG. 1 is a sectional view of an optical system portion of a printing apparatus to which an autofocus mechanism according to an embodiment of the present invention is applied, and FIG. 2 is a block diagram of an offset correction function section of the autofocus mechanism in FIG. 1. be. 1 reticle, 2: projection optical system, 3: autofocus mechanism, 4: air nozzle end face, 5: wafer, 6: air sensor coordinate origin, 31: atmospheric pressure sensor, 32: temperature sensor, 33: humidity sensor, 34: focus Detector (air sensor), 35: Microprocessor, 36: Z-axis drive device.

Claims (1)

【特許請求の範囲】 １、投影光学系を用いたプロジェクション方式のパター
ン転写装置に用いられ感光体のパターン転写面を所定の
ピント基準面に合致させることによりピント合せするオ
ートフォーカス機構であつて、該パターン転写装置上に
配置され該パターン転写装置の環境条件を検知するセン
サ手段と、該センサ手段の出力に基づいて上記ピント基
準面を光軸方向に移動しピント位置を補正する手段とを
具備することを特徴とするオートフォーカス機構。 ２、前記センサ手段が、気圧センサおよび湿度センサの
一方または双方である特許請求の範囲第１項記載のオー
トフォーカス機構。 ３、前記ピント位置補正手段が、所定の演算式に基づい
て前記ピント基準面の位置または移動量を算出するもの
である特許請求の範囲第１または２項記載のオートフォ
ーカス機構。 ４、前記ピント位置補正手段が、前記環境条件に対応す
るピント面の位置を予め記憶する手段と、前記センサ手
段の出力に対応する上記ピント面を前記ピント基準面と
して読み出す手段とを含む特許請求の範囲第１または２
項記載のオートフォーカス機構。[Scope of Claims] 1. An autofocus mechanism that is used in a projection-type pattern transfer device using a projection optical system and focuses by aligning a pattern transfer surface of a photoreceptor with a predetermined focus reference surface, A sensor means arranged on the pattern transfer device to detect environmental conditions of the pattern transfer device, and a means for moving the focus reference plane in the optical axis direction based on the output of the sensor means to correct the focus position. An autofocus mechanism that is characterized by: 2. The autofocus mechanism according to claim 1, wherein the sensor means is one or both of an air pressure sensor and a humidity sensor. 3. The autofocus mechanism according to claim 1 or 2, wherein the focus position correction means calculates the position or movement amount of the focus reference plane based on a predetermined calculation formula. 4. A patent claim in which the focus position correction means includes means for storing in advance the position of the focus plane corresponding to the environmental condition, and means for reading out the focus plane corresponding to the output of the sensor means as the focus reference plane. Range 1 or 2
Autofocus mechanism as described in section.
JP59218571A 1984-10-19 1984-10-19 Automatic focusing mechanism Pending JPS6198314A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
JP59218571A JPS6198314A (en) 1984-10-19 1984-10-19 Automatic focusing mechanism
DE19843447488 DE3447488A1 (en) 1984-10-19 1984-12-27 PROJECTION DEVICE
FR848419987A FR2572197B1 (en) 1984-10-19 1984-12-28 PROJECTION APPARATUS
GB8432820A GB2166879B (en) 1984-10-19 1984-12-31 A projection apparatus
US07/220,440 US4998821A (en) 1984-10-19 1988-07-13 Projection apparatus
FR888816238A FR2623304B1 (en) 1984-10-19 1988-12-09 APPARATUS FOR PROJECTING BY A OPTICAL SYSTEM A DRAWING CARRIED BY A FIRST OBJECT ON A SECOND OBJECT

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59218571A JPS6198314A (en) 1984-10-19 1984-10-19 Automatic focusing mechanism

Publications (1)

Publication Number Publication Date
JPS6198314A true JPS6198314A (en) 1986-05-16

Family

ID=16722029

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59218571A Pending JPS6198314A (en) 1984-10-19 1984-10-19 Automatic focusing mechanism

Country Status (1)

Country Link
JP (1) JPS6198314A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63237017A (en) * 1987-03-26 1988-10-03 Nec Corp Automatic focus adjustment mechanism
JP2020046581A (en) * 2018-09-20 2020-03-26 株式会社Ｓｃｒｅｅｎホールディングス Drawing apparatus and drawing method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63237017A (en) * 1987-03-26 1988-10-03 Nec Corp Automatic focus adjustment mechanism
JP2020046581A (en) * 2018-09-20 2020-03-26 株式会社Ｓｃｒｅｅｎホールディングス Drawing apparatus and drawing method

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