CN117405227A

CN117405227A - Extremely high resolution spectrometer for monitoring semiconductor processes

Info

Publication number: CN117405227A
Application number: CN202310875008.1A
Authority: CN
Inventors: A·W·科伊尼
Original assignee: Verity Instruments Inc
Current assignee: Verity Instruments Inc
Priority date: 2022-07-15
Filing date: 2023-07-17
Publication date: 2024-01-16

Abstract

The present application relates to a very high resolution spectrometer for monitoring semiconductor processes. An extremely high resolution optical instrument is provided that can be used to monitor semiconductor processes. In this application space, very high resolution may be considered sufficient to permit resolution of individual molecular trans-excitation emission lines. In one example, an optical instrument is provided, comprising: (1) an optical interface that receives an optical fiber; (2) A narrow bandpass filter that filters out a portion of the optical signal received via the optical fiber; (3) An optical component selectively combined to process at least a portion of an unfiltered optical signal, wherein the optical component includes a sensor that receives the unfiltered optical signal; and (4) one or more processors that process the electrical signals from the sensors. The optical instrument may be a spectrometer suitable for process control instruments.

Description

Extremely high resolution spectrometer for monitoring semiconductor processes

Cross Reference to Related Applications

The present application claims the benefit of U.S. provisional application No. 63/389,542 entitled "extremely high resolution spectrometer for monitoring semiconductor processing (Very High Resolution Spectrometer for Monitoring of Semiconductor Processes)" filed by andelu waxkunni (Andrew Weeks Kueny) on day 7, 2022, which is commonly assigned with the present application and incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates generally to spectroscopy (optical spectroscopy) systems and methods of use, and more particularly, to compact very high resolution spectrometers for monitoring optical emissions from semiconductor processes.

Background

Optical monitoring of semiconductor processes is an effective method for controlling processes such as etching, deposition, chemical mechanical polishing and implantation. Optical Emission Spectroscopy (OES) and Interferometry Endpoint (IEP) are two basic types of data collection modes of operation. In OES applications, light emitted from a process (typically from a plasma) is collected and analyzed to identify and track changes in atomic and molecular species that are indicative of the state or progress of the process being monitored.

Disclosure of Invention

In one aspect, a method of processing an optical signal is disclosed. In one example, a method includes: (1) receiving an optical signal; (2) filtering the optical signal using a narrow band pass filter; and (3) processing the filtered optical signal using selective combinations of optical components based on the desired resolution.

In another aspect, the present disclosure provides an optical instrument. In one example, an optical instrument includes: (1) an optical interface that receives an optical fiber; (2) A narrow bandpass filter that filters out a portion of the optical signal received via the optical fiber; (3) An optical component selectively combined to process at least a portion of the unfiltered optical signal, wherein the optical component includes a sensor that receives the unfiltered optical signal; and (4) one or more processors that process the electrical signals from the sensors.

In yet another aspect, the present disclosure provides a semiconductor monitoring system. In one example, a system includes: (1) an optical fiber; and (2) an improved Czerny-Turner spectrometer having at least one narrow band pass filter filtering out a portion of the optical signal received via the optical fiber.

Drawings

Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of a system for monitoring and/or controlling the state of a plasma or non-plasma process within a semiconductor process tool using OES and/or IEP;

FIG. 2 is a graph of a portion of the spectrum of emissions from CN species around 387nm, with a typical resolution of approximately 1nm;

FIG. 3 is a graph of a portion of the spectrum of emissions from CN species around 387nm, with a typical resolution of approximately 0.023nm;

FIG. 4 is a graph of a portion of the transmission spectrum of a bandpass filter centered at about 386.7 nm;

FIG. 5 is a graph of a portion of the spectrum of emissions from CN species around 387nm, with typical resolution of approximately 0.023nm, with and without band pass filters centered around 386.7 nm;

FIG. 6 is a graph of a portion of the spectrum of emissions from CN species around 387nm, with a typical resolution of approximately 1nm, showing specific signal and noise characteristics;

FIG. 7 is a graph of a portion of the spectrum of emissions from CN species around 387nm, with a typical resolution of approximately 1nm, showing degraded signal and noise characteristics due to stray light and other optical contamination;

FIG. 8 is a schematic diagram of the optical layout of a Cherny-Telnet spectrometer;

FIG. 9 is an image of ray traced results of a spectrometer arrangement according to the present disclosure;

FIG. 10 is an image of a plot of light points of the spectrometer arrangement of FIG. 8 according to the present disclosure; and is also provided with

Fig. 11 is a block diagram of a spectrometer and a particular related system according to the present disclosure.

Detailed Description

In the following description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized. It is also to be understood that structural, procedural and system changes may be made without departing from the spirit and scope of the present invention. The following description is, therefore, not to be taken in a limiting sense. For clarity of explanation, identical features shown in the drawings are indicated with identical reference numerals, and similar features shown in alternative embodiments in the drawings are indicated with similar reference numerals. Other features of the present invention will be apparent from the accompanying drawings and from the detailed description that follows. It should be noted that for clarity of illustration, specific elements in the drawings may not be drawn to scale.

Semiconductor processes continue to advance to faster processes, smaller feature sizes, more complex structures, larger wafers, and more complex process chemistries placing great demands on process monitoring techniques. For example, higher data rates are needed to accurately monitor much faster etch rates on very thin layers, where variations in angstroms (a few atomic layers) are critical for fin field effect transistor (FINFET) and three-dimensional NAND (3D NAND) structures, for example. In many cases, both OES and IEP methods require wider optical bandwidths, higher resolutions, and greater signal-to-noise ratios to help detect small changes in both reflectance and optical emissions. As process equipment itself becomes more complex and expensive, cost and packaging size are also facing continued pressure. All of these requirements seek to improve the optical monitoring performance of semiconductor processes. Regardless of OES or IEP methods, an important component of many optical monitoring systems is the spectrometer, and which is capable of consistently and accurately converting received optical data into electrical data to control and monitor semiconductor processes.

The increasing complexity of process chemistries and the reduction of open areas of the process are driving advances in process monitoring systems and improvements in signal-to-noise ratio and signal detection capability are generally desired. While improvements in electronic components such as a/D converters, power supplies, and higher NEP sensors may be provided to perform better, the utility of process control information may be inhibited by other factors. One such factor is spectrometer resolution. At existing resolutions, information may provide a general trend of semiconductor processing at very low S/N ratios and may not support robust process control. Additional information exists in very high resolution spectra where rotational and vibrational emission lines can be isolated for highly specific individual or differential characterization. For example, while a semiconductor plasma process may indicate small changes in spectral emissions when resolved at 1nm, the same emissions when resolved at much higher resolutions will isolate changes in individual rotational and/or vibrational emissions that are more sensitive to plasma, chemical, and concentration changes. The increased resolution may provide a deep understanding of the use of fast pulsed plasmas, where the variable lifetime of the excited state of the species and the plasma temperature are of particular concern.

Accordingly, the present disclosure provides a very high resolution spectrometer that can be used to monitor semiconductor processes. In this application space, very high resolution may be considered sufficient to permit resolution of individual molecular trans-oscillation (rovibration) emission lines. The very high resolution may be in the range of 0.01 to 0.1 nm. A resolution of 0.025nm is used in at least one example herein as an example of very high resolution. The present disclosure includes at least one embodiment of an improved high resolution spectrometer that combines a predetermined process-specific wavelength range with extremely high resolution with improved out-of-band light rejection to provide a suitable process control instrument.

In particular, with respect to monitoring and assessing the status of a semiconductor process within a process tool, fig. 1 illustrates a block diagram of a process system 100 utilizing OES and/or IEPs to monitor and/or control the status of a plasma or non-plasma process within a semiconductor process tool 110. The semiconductor process tool 110, or simply, the process tool 110, generally encloses a wafer 120 and possibly a process plasma 130 in a generally partially evacuated volume of a chamber 135, which may contain various process gases. The process tool 110 may include or simply be referred to as one or more optical interfaces 140, 141, and 142 to permit observation within the chamber 135 at various positions and orientations. Interfaces 140, 141, and 142 may include various types of optical elements such as, but not limited to, filters, lenses, windows, apertures, optical fibers, and the like.

For IEP applications, the light source 150 may be connected with the interface 140 directly or via a fiber optic cable assembly 153. As shown in such a configuration, the interface 140 is oriented perpendicular to the surface of the wafer 120 and is generally centered with respect to the wafer. Light from the light source 150 may enter the interior volume of the chamber 135 in the form of a collimated beam 155. The beam 155, after being reflected from the wafer 120, may again be received by the interface 140. In a common application, the interface 140 may be an optical collimator. After being received by the interface 140, the light may be transmitted to the spectrometer 160 via the fiber optic cable assembly 157 for detection and conversion to digital signals. The light may include both source light and detected light, and may include a wavelength range from Deep Ultraviolet (DUV) to Near Infrared (NIR), for example. The wavelength of interest may be selected from any sub-range of wavelength ranges. Additional optical interfaces (not shown in fig. 1) oriented perpendicular to wafer 120 may be used for larger substrates or where wafer non-uniformity needs to be understood. The processing tool 110 may also include additional optical interfaces positioned in different locations for other monitoring options.

For OES applications, the interface 142 may be oriented to collect light emissions from the plasma 130. The interface 142 may simply be a viewport or may additionally include other optics such as lenses, mirrors, and optical wavelength filters. The fiber optic cable assembly 159 may direct any collected light to the spectrometer 160 for detection and conversion to digital signals. The spectrometer 160 may include a CCD sensor and a converter for detection and conversion. Multiple interfaces may be used, either individually or in parallel, to collect OES-related optical signals. For example, interface 141 may be positioned to collect emissions from near the surface of wafer 120, while interface 142 may be positioned to view the body of plasma 130, as shown in fig. 1.

In many semiconductor processing applications, OES and IEP optical signals are commonly collected, and such collection presents a number of problems for the use of the spectrometer 160. Typically, the OES signal is continuous in time, while the IEP signal may be continuous or discrete in time. The mixing of these signals creates a number of difficulties because process control typically requires the detection of small changes in OES and IEP signals, and the inherent changes in either signal can mask the observation of changes in the other signal. Supporting multiple spectrometers for each signal type is disadvantageous because of, for example, the cost, complexity, inconvenience of signal timing synchronization, calibration, and packaging.

After detection by the spectrometer 160 and conversion of the received optical signal to an analog electrical signal, the analog electrical signal is typically amplified and digitized within a subsystem of the spectrometer 160 and passed to a signal processor 170. The signal processor 170 may be, for example, an industrial PC, PLC or other system that employs one or more algorithms to generate an output 180, e.g., analog or digital control values representing the intensity of a particular wavelength or the ratio of two wavelength bands. Instead of a separate device, the signal processor 170 may alternatively be integrated with the spectrometer 160. The signal processor 170 may employ OES algorithms that analyze the emission intensity signal at predetermined wavelengths and determine trend parameters related to process conditions, and may be used to access the conditions, such as in endpoint detection, etch depth, etc., for example. For IEP applications, the signal processor 170 may employ an algorithm that analyzes a wide bandwidth portion of the spectrum to determine film thickness. For example, see U.S. patent 7,049,156, incorporated herein by reference, for systems and methods for in situ monitoring and control of film thickness and trench depth (System and Method for In-situ Monitor and Control of Film Thickness and Trench Depth). The output 180 may be transmitted to the process tool 110 via the communication link 185 for monitoring and/or modifying a production process occurring within the chamber 135 of the process tool 110.

The components shown and described in fig. 1 are simplified for convenience and are well known. In addition to common functionality, the spectrometer 160, the signal processor 170, or a combination of both, may be configured to identify stationary and transient light and non-light signals, and process these signals according to the methods and/or features disclosed herein. Accordingly, the spectrometer 160 or the signal processor 170 may include algorithms, processing power, and/or logic to identify and process the optical signals and the temporal trends extracted from the optical signals. The algorithms, processing capabilities, and/or logic may be in the form of hardware, software, firmware, or any combination thereof. The algorithms, processing power and/or logic may be within one computing device or may be distributed across multiple devices such as the spectrometer 160 and the signal processor 170. The treatment may be performed at very high resolution as disclosed herein to achieve a treatment, such as emission of a gas species as mentioned below.

A spectrometer, such as spectrometer 160, has a fixable operating wavelength range and one or more filters may be used to select a portion of the range. The filter 161 provides an example of a narrow band filter that may select a portion of the operating range of the spectrometer 160. The filter shown in fig. 4 provides an example in which a narrowband filter may be used. Instead of being inside the spectrometer like filter 161, the narrowband filter may be outside the spectrometer (e.g., at least partially outside the housing of the spectrometer), as represented by filter 1131 in fig. 11. The narrowband filter may be selected to correspond to emissions of one or more gas species to be treated.

The various gas species used in semiconductor processing have molecular emissions that contain information that is not readily available when detected by prior art control spectrometers having a typical resolution of 1nm. Many different molecular species are possible and include, but are not limited to, siF _x 、CN、CO _x 、N _x And NO _x . Examples relating to the approximately 387nm spectral emission of CN will be discussed herein.

Figures 2 and 3 show graphs of spectra from CN species emissions, which demonstrate how the resolution used affects the type and amount of information obtained. Fig. 2 shows a graph of a portion of a spectrum 200 of emissions from CN species around 387nm, with a typical resolution of approximately 1nm. When compared to fig. 3, which shows a graph of a portion of the spectrum 300 of the emission from CN species at 387nm, with a typical resolution of approximately 0.023nm, it is apparent that in the now separately resolved rotation and vibration emission, considerable information can be obtained for process control. The graphs of fig. 2 and 3 have an x-axis of wavelength in nanometers and a y-axis of signal count in arbitrary dimensions.

As can be seen from a comparison of fig. 3 and fig. 2, the resolution used affects the amount of information obtained. However, the change in resolution of the spectrometer is an important change and requires modification and/or physical adjustment of most of the major components of the optical bench. Due to extreme reliability issues of semiconductor processing, it is often not feasible to have adjustable components in the optics table of the monitoring system. Furthermore, while some high resolution spectrometer systems are available, these systems are typically very large (multiple feet in size) and are therefore not compatible with integration into semiconductor processing equipment.

An additional complication with the monitoring of semiconductor processes is that emissions from such processes can provide extremely broad band spectral features, which if mishandled, can cause unwanted stray light and increased noise levels on the collected signals. The present disclosure describes at least one embodiment of an improved high resolution spectrometer that combines a predetermined process-specific wavelength range with extremely high resolution with improved out-of-band light rejection to provide a suitable process control instrument. Fig. 4-5 illustrate examples of spectral graphs representing applications for a particular range of bandpass filters in combination with very high resolution. Fig. 6 to 7 illustrate comparative examples with a rather low resolution of 1nm and poor out-of-band light rejection. The comparison of fig. 4-7 emphasizes the benefits of a high resolution spectrometer as described herein.

Fig. 4 shows a graph of a portion of the transmission spectrum 400 of a bandpass filter centered at about 386.7nm, and shows out-of-band rejection provided by such a filter. The rejection of such filters may be Optical Density (OD) 6 or greater and provide strong rejection of undesired signals. Fig. 5 shows a plot of a portion of the spectrum of emissions from CN species around 387nm with typical resolution of approximately 0.023nm with and without the addition of a bandpass filter centered around 386.7nm, such as shown in fig. 4. In fig. 5, spectrum 510 is "with" a bandpass filter, and spectrum 520 is "without" a bandpass filter. The spectral width of the bandpass filter may constrain the useful wavelength range for the collected spectrum. For the bandpass filter of fig. 4, the useful spectral range is approximately 1.0nm. Other filters may provide a wider or narrower useful spectral range and may be selected based on the desired wavelength range for particular species monitoring and process control. The filter may be a single band or a multi-band filter, such as a comb filter, and provides spectral bands suitable for one or more species. Fig. 5 has an x-axis of wavelength in nanometers and a y-axis of signal count in arbitrary dimensions.

The benefits of including a bandpass filter may be demonstrated by a comparison of fig. 6 and 7. Fig. 6 shows a graph of a portion of the spectrum 600 of emissions from CN species around 387nm, with a typical resolution of approximately 1nm, showing specific signal and noise characteristics. If the background light signal is not reduced, the same spectrum as in FIG. 7 may be presented, showing a spectrum 700 with degraded signal and noise characteristics due to stray light and other optical contamination. Fig. 6 and 7 have the x-axis of wavelengths in nanometers. In fig. 6, the y-axis is the normalized signal, while in fig. 7, the y-axis is the signal count.

To address the process requirements of a suitably limited spectral range, with useful signal and noise characteristics in a compact package, a cherni-tenna spectrometer configuration may be used. Fig. 8 shows a general schematic of an optical layout of a cut-ney-terna spectrometer 800 that has been modified in accordance with the principles of the present disclosure. General schematic diagrams refer to the "broadband astigmatic cherni-terna imaging spectrometer using spherical mirrors (Broadband astigmatism-free Czerny-Turner imaging spectrometer using spherical mirrors)", application selection (appl. Opt.) 48,3846-3853 (2009), tobias Witting) and a. Austenite (a. Walmsley). In addition to the general features of the chernissena spectrometer as identified in the legend of fig. 8, the chernissena spectrometer 800 is customized according to aspects of the present disclosure by adding one or more filters represented by example placements of filters 810 and 820. As discussed with respect to fig. 11, more than one filter may be added for improved processing, and more than one type of filter may be used.

A bandpass filter such as that depicted in fig. 4 may be conveniently located within the optical path of the cut-tenna spectrometer 800. The filter may be located substantially anywhere between the entrance slit of the spectrometer and the detector. The filter 161 of fig. 1 represents the placement of the filter within the spectrometer. Better filtering performance with a filter within the spectrometer may be achieved by placing the filter in a portion of the collimated light path within the spectrometer 800 (e.g., after mirror C in the light path as represented by filter 810). A filter, such as represented by filter 820, may be positioned before the entrance slit of spectrometer 800 to block unwanted light from entering any portion of spectrometer 800. The filter 1131 of fig. 11 represents the placement of the filter outside the spectrometer prior to the entrance slit.

As described herein, a filter used with the cut-tenna spectrometer 800 (e.g., filter 810 or 820) may be selected for processing the CN 387nm portion of the spectrum or other desired portions of the spectrum. Fig. 9 shows an image 900 of the ray tracing results of this spectrometer with a layout optimized for the CN 387nm portion of the spectrum. A slit S, a collimator lens C, a grating G, a focusing lens F and a detector D corresponding to the features shown in fig. 8 are also shown in fig. 9. The spectrometer modeled by the ray tracing shown in fig. 9 is capable of spanning a wavelength range of approximately 380 to 410nm, which can be used to monitor emissions from species, e.g., siN, siF ₂ CN emission around CH, CO and 387 nm.

The spectrometer design of fig. 9 supports this wavelength range with a resolution of 0.025nm in a volume of approximately 6 x 8 inches. Resolution is achieved by the combined selection of grating, mirror, slit size and sensor. For this particular wavelength range and resolution, a grating with 2400 lines/mm may be used with a sensor, such as the S7031 CCD detector from Hamamatsu (Hamamatsu) or other detector with appropriate pixel size (about 7 to 25 um) and array length (about 1000 to 3000 pixels). For example, S11071 from Pinus maritima with a 2048×64 element pixel array and 14um pixels can be used. Fig. 10 shows an image 1000 of a light point plot for the spectrometer layout of fig. 8 for an image of two spectral lines spaced about 0.025nm apart from 386nm by 5 x 100um.

Fig. 11 is a block diagram of an optical system 1100 including a spectrometer 1110 and certain related systems according to one embodiment of the present disclosure. Spectrometer 1110 can incorporate the systems, features, and methods disclosed herein to facilitate measuring, characterizing, analyzing, and processing optical signals from semiconductor processes, and can be associated with spectrometer 160 of fig. 1. The spectrometer 1110 may receive an optical signal from external optics 1130, for example, via fiber optic cable assemblies 157 or 159, and may send data after integration and conversion to an external system 1120, such as output 180 of fig. 1, which may also be used to control the spectrometer 1110 by, for example, selecting an operating mode as defined herein or controlling integration timing. The spectrometer 1110 can include an optical interface 1140, such as a micro-assembly (SMA) or ferrule-connector (FC) fiber optic connector or other optical-mechanical interface. The optical-mechanical interface controls the orientation of the fiber array relative to the input of the spectrometer so that the CCD reading procedure can accurately isolate the corresponding channels. Other optical components 1145, such as slits, lenses, filters, and gratings, may be used to form, direct, and colorimetrically separate the received light signals and direct them to the sensor 1150 for integration and conversion. Filter 1146 represents one of the filters. The filter 1146 may be a broad filter corresponding to the operating wavelength range of the spectrometer 1110. The filter 1146 may also be a bandpass filter, such as a narrow bandpass filter as referenced in fig. 4, 5, and 8, for selecting a portion of the operating wavelength range of the spectrometer 1110. Thus, filter 1146 may be configured based on the desired wavelength or wavelength range of interest. Configuring the bandpass filter may occur at the time of manufacture. Thus, the spectrometer 1110 can be a configurable optical solution with a small form factor for processing. The optical component 1145 may comprise the optical components mentioned with reference to fig. 8-9, such as gratings, mirrors, slit sizes, which are selected and combined to achieve a desired resolution. The optical components 1145 may be selectively combined to provide a wavelength range of approximately 380 to 410nm, for example, with a resolution of 0.025 nm; all within the volume of spectrometer 1100 defined by dimensions of approximately 6 x 8 inches. Selectively combining the optical components 1145 may also occur at the time of manufacture.

Filter 1131 represents another example of a narrowband filter, such as the narrowband pass filters as mentioned in fig. 4, 5, and 8, which may be positioned outside spectrometer 1110. Thus, filter 1131 may be adapted in the field after fabrication to select a particular portion of the operating wavelength range of spectrometer 1110. When present, filter 1146 may be a broad filter corresponding to the operating wavelength range of spectrometer 1110. In other words, a single narrow bandpass filter (e.g., 1131) may be used with a wideband filter (e.g., 1146). Combinations of bandpass filters may also be used or interchanged for adaptability.

The low-level functions of the sensor 1150 may be controlled by elements such as the FPGA1160 and the processor 1170. After optical-to-electrical conversion, the analog signals may be directed to an a/D converter 1180 and converted from electrical analog signals to electrical digital signals, which may then be stored in memory 1190 for immediate or later use and transmission, such as to an external system 1120 (see, signal processor 170 of fig. 1). Although some interfaces and relationships are indicated by arrows, not all interaction and control relationships are indicated in FIG. 11. The spectral data shown in fig. 3 may be collected, stored, and/or acted upon, for example, within/by one or more of the memory/storage 1190, the FPGA1160, the processor 1170, and/or the external system 1120. Memory/storage 1190, FPGA1160, processor 1170, and/or external system 1120 provide examples in which processing capabilities, logic, and/or operational instructions corresponding to algorithms for processing optical signals as disclosed herein may be stored. The spectrometer 1110 also includes a power supply 1195, which may be a conventional AC or DC power supply commonly included with spectrometers.

Portions of the disclosed embodiments may relate to computer storage products with a non-transitory computer-readable medium that have program code thereon for performing various computer-implemented operations that embody a portion of an apparatus, device, or perform steps of a method set forth herein. Non-transitory as used herein refers to all computer readable media except transitory propagating signals. Examples of non-transitory computer-readable media include, but are not limited to: magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROM discs; magneto-optical media such as optical disks; and hardware devices that are specially configured to store and perform program code, such as ROM and RAM devices. Examples of program code include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. Configuration refers to, for example, design, construction or programming with necessary logic, algorithms, processing instructions and/or features to perform one or more tasks.

Variations and the like described above may be made in the optical measurement systems and subsystems described herein without departing from the scope of the invention. For example, while certain examples are described in connection with semiconductor wafer processing equipment, it is to be understood that the optical measurement systems described herein may be adapted for other types of processing equipment, such as roll-to-roll thin film processing, solar cell fabrication, or any application where high precision optical measurements may be required. Furthermore, while certain embodiments discussed herein describe the use of a common light analysis device, such as an imaging spectrometer, it should be understood that multiple light analysis devices with known relative sensitivities may be utilized. Furthermore, although the term "wafer" is used herein in describing aspects of the present invention, it should be understood that other types of workpieces, such as quartz plates, phase shift masks, LED substrates, and other non-semiconductor processing related substrates, as well as workpieces, including solid, gaseous, and liquid workpieces, may be used.

The exemplary embodiments described herein were chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. The particular embodiments described herein are in no way intended to limit the scope of the invention, as the invention may be practiced in a variety of modifications and environments without departing from the scope and intent of the invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein.

The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As will be appreciated by one skilled in the art, the present invention may be embodied as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that are commonly referred to herein as a "circuit" or "module. Furthermore, the present invention may take the form of a computer program product having computer-usable program code embodied in a computer-usable storage medium.

Various aspects of the disclosure, including apparatus, systems, and methods as disclosed herein, may be claimed. Aspects disclosed herein and referred to in the summary include:

A. a method of processing an optical signal, comprising: (1) receiving an optical signal; (2) filtering the optical signal using a narrow band pass filter; and (3) processing the filtered optical signal using selective combinations of optical components based on the desired resolution.

B. An optical instrument, comprising: (1) an optical interface that receives an optical fiber; (2) A narrow bandpass filter that filters out a portion of the optical signal received via the optical fiber; (3) An optical component selectively combined to process at least a portion of the unfiltered optical signal, wherein the optical component includes a sensor that receives the unfiltered optical signal; and (4) one or more processors that process the electrical signals from the sensors.

C. A semiconductor monitoring system, comprising: (1) an optical fiber; and (2) an improved chenille-tenna spectrometer having at least one narrow band pass filter that filters out a portion of the optical signal received via the optical fiber.

Each of aspects A, B and C can have one or more of the following additional elements in combination: element 1: wherein the optical component comprises a combination of grating, mirror and slit sizes. Element 2: wherein the optical component comprises a sensor. Element 3: wherein the method is performed by a spectrometer having a small form factor. Element 4: wherein the spectrometer is a modified cherni-terna spectrometer. Element 5: wherein the desired resolution is selected based on processing emissions from one or more gas species. Element 6: wherein one or more of the gas species comprises SiN, siF ₂ CH, CO and CN. Element 7: wherein one or more species SiN, siF are selected ₂ Individual species in CH, CO and CN for processing. Element 8: wherein the resolution is 0.025nm. Element 9: wherein the combination of optical components is selected during manufacture. Element 10: wherein the narrow band pass filter is adaptable after manufacturing. Element 11: wherein the optical component comprises a combination of grating, mirror and slit sizes. Element 12: wherein the optical instrument is a spectrometer having a small form factor. Element 13: wherein the spectrometer is a modified cherni-terna spectrometer. Element 14: wherein the optical components are selectively combined to achieve a desired resolution based on processing emissions from one or more gas species. Element 15: wherein one or more of the gas species comprises SiN, siF ₂ CH, CO and CN. Element 16: wherein one or more species of SiN are selected,SiF ₂ Individual species in CH, CO and CN for processing. Element 17: wherein the combination of optical components is selected during the manufacture of the optical instrument. Element 18: wherein the narrow band pass filter is adaptable after fabrication of the optical instrument.

Claims

1. A method of processing an optical signal, comprising:

receiving an optical signal;

filtering the optical signal using a narrow band pass filter; and

the filtered optical signal is processed using a selective combination of optical components based on a desired resolution.

2. The method of claim 1, wherein the optical component includes a combination of grating, mirror, and slit sizes.

3. The method of claim 1, wherein the optical component comprises a sensor.

4. The method of claim 1, wherein the method is performed by a spectrometer having a small form factor.

5. The method of claim 4, wherein the spectrometer is a modified czernix-Turner (Czerny-Turner) spectrometer.

6. The method of claim 1, wherein the desired resolution is selected based on processing emissions from one or more gas species.

7. The method of claim 6, wherein the one or more gas species comprise SiN, siF ₂ CH, CO and CN.

8. The method of claim 6, wherein the one or more species SiN, siF are selected ₂ Individual species in CH, CO and CN for processing.

9. The method of claim 6, wherein the resolution is 0.025nm.

10. The method of claim 1, wherein the combination of optical components is selected during manufacturing.

11. The method of claim 1, wherein the narrow band pass filter can be adapted after fabrication.

12. An optical instrument, comprising:

an optical interface that receives an optical fiber;

a narrow bandpass filter that filters out a portion of the optical signal received via the optical fiber;

an optical component selectively combined to process at least a portion of an unfiltered optical signal, wherein the optical component includes a sensor that receives the unfiltered optical signal; and

one or more processors that process the electrical signals from the sensors.

13. The optical instrument of claim 12, wherein the optical component includes a combination of grating, mirror, and slit sizes.

14. The optical instrument of claim 12, wherein the optical instrument is a spectrometer having a small form factor.

15. The optical instrument of claim 14, wherein the spectrometer is a modified cher-tenna spectrometer.

16. The optical instrument of claim 14, wherein the optical components are selectively combined to achieve a desired resolution based on processing emissions from one or more gas species.

17. The optical instrument of claim 16, wherein the one or more gas species comprise SiN, siF ₂ CH, CO and CN.

18. The optical instrument of claim 17, wherein the one or more species SiN, siF are selected ₂ Individual species in CH, CO and CN for processing.

19. The optical instrument of claim 16, wherein the resolution is 0.025nm.

20. The optical instrument of claim 12, wherein the combination of optical components is selected during fabrication of the optical instrument.

21. The optical instrument of claim 12, wherein the narrow band pass filter is adaptable after fabrication of the optical instrument.

22. A semiconductor monitoring system, comprising:

an optical fiber; and

an improved cut-tenna spectrometer having at least one narrow band-pass filter that filters out a portion of an optical signal received via the optical fiber.