TW200424499A - Determination of center of focus by parameter variability analysis - Google Patents

Abstract

A method for the determination of center of focus and process control for a lithographic tool is provided. Diffraction signatures are obtained from a plurality of diffraction structures located within multiple different focus setting fields. Variability of diffraction signatures with each field are determined, by direct analysis or comparison to a library. The variability or uniformity of the values of a chosen feature in the diffractive structure which is the whole or a subset, located in each field, is computed. The variation or uniformity may be represented by any measure, including the standard deviation or the range of values of a chosen feature or the variability or uniformity of the diffraction signatures themselves, such as by RMS difference or intensity range. The methods may be used for process control and monitoring of focus drift by determining the intra-field variation of diffraction signatures of multiple diffraction structures in a series of wafers, so as to determine the varied degree of the variability or uniformity.

Description

200424499 V. Description of the Invention α) [Technical Field] This application claims US Patent Provisional Application Serial No. 60/4 62, 353, named after Determination of Center Of FocuS in Lithographic Appiications The patent profit and profit, filed on April 10, 2003, and its detailed items are included here for reference. The present invention relates to a method for determining dimensional changes by using diffractive structures located at different positions on a wafer to determine the application parameters of engraving; including the determination of the focal length center of the engraving application, such as photoresistance. Engraving and printing wafer processing, and procedures and quality control using these decisions. [Prior Art] Please note that the following discussion involves some authors and publication year publications, and because they are the latest publication date, some publications are not considered to be past technology compared with the present invention. These publications are discussed here for a more complete background and should not be interpreted as a prior art for patent granting purposes. There are a variety of useful applications of lithography in the semiconductor, childless and related industries. Engraving is used in the manufacture of semiconductor devices, such as integrated circuits produced on wafers, as well as flat-panel displays, magnetic disk readers, and so on. In some applications, engraving is a method of space-regulating light work 'used to transfer a pattern on a mask or scoring plate to a substrate "(Zheng Wei Qian Wei layer) The resist layer is developed, and the exposed pattern is etched or retained (negative resist), and three-degree blank lines are formed in the resist layer.

Page 5 200424499 V. Description of the image of the invention (2). Of course, in addition to this photoresist engraving, there are other types of engraving. A certain type of engraving printing technology, which is specially used in the semiconductor industry, uses a wafer stepper; its typical examples include a reduction lens and illumination light source, a wafer mirror stage, and an optical reticle reticle. , Cassette cassette and one = as a workbench. Modern stepper equipment is used for both positive and negative resist methods, and uses the original step-and-repeat form or step-and-scan form, or both. -Exposure and focal length determine the quality of the developed image pattern, such as those using photoresist-type lithographic resists. The exposure determines the average energy per unit area of the image, and is set by the lighting time and intensity. Focal length determines how much the change is reduced relative to the image at the point of focus. The focal length is set by the position of the surface of the anti-corrosion layer relative to the plane of focus of the imaging system. ^ Local variations in exposure and focal length can be caused by changes in resist thickness, substrate shape, and shift in focal length of stencil tools. Because of possible changes in exposure and focal length, patterns generated through stereotypes need to be monitored to determine if they are within acceptable tolerances. The control of exposure and focal length is particularly important where the stencil printing process is used to generate sub-micron lines. / Various methods and equipment have been used to determine the focal length of steppers and similar stenciling tools. Scanning electron microscope (SEM) and similar equipment have been used. However, when the resolvable shape of a scanning electron microscope is less than 0 t micron, the processing procedure will be expensive, requiring a high-degree vacuum chamber, which is relatively slow in operation and difficult to automate. Optics

200424499 V. Description of the invention (3) —---- The microscope can be used, but it does not have the analytical ability to process sub-micron structures. Other methods include the development of specialized targets and test masks, such as those disclosed in U.S. Patent Nos. 5,71 2, 70 7, 5, 95 3, 1 28 and 6, 0 88, 1 1 3 Λ. The gold plating error method is also known, as disclosed in US Patent No. $ 9 52, 1 32. However, these methods still require the use of scanning electron microscopes, light microscopes, or similar direct measurement tools.

Various types of political radiometers, related devices, and measurement methods have been used to describe the microstructure characteristics of the following facility materials: Microelectronics and optoelectronic semiconductor materials, computer hard disks, optical disks, micro-polished Optical components, and other materials with lateral dimensions ranging from tens of microns to less than one-tenth of a micron. For example, ’CDS 2000 optical scatterometer is manufactured and sold by Accent Optical Technologies, Inc.

A fully automatic non-destructive critical dimension (C j)) measurement and profile analysis system is partially disclosed in U.S. Patent No. 5,703,692. This device can repeatedly analyze the key dimensions of less than 1 nanometer, and simultaneously measure the profile profile and perform the estimation of the thickness of the laminate. The device monitors generally diffracted light, which may include, but is not limited to, a single diffraction order of intensity 'as a function of the incident angle of the illumination beam. Changes in the light intensity of the zeroth or reflection order and the higher diffraction order of the specimen can be monitored in this way, and the information provided is used to determine the nature of the irradiated specimen. Because the process used to make the sample target determines the nature of the sample target, this information is also used for indirect monitoring of the process. This method is described in the literature of semiconductor processing programs. There are some materials that teach optical scatterometer analysis methods and devices, including

Page 7 200424499 V. Description of the invention (4) ~ Contained by the following US patent numbers 4,71 〇, 64 2, 5, 1 64, 79 0, 5,241, 369, 5, 703, 692, 5, 867,276, 5,889, 593, 5,912 741, and 6, 10 0, 9 8 5. '' Another technique to determine the optimal focal length is to use a reticle specially designed based on the phase shifting technology (R Edwards, P. Ackmann, C. Fischer, π Characterization of Autofocus Consistency and Accuracy on AS ML Stepper Using Phase-shifted Focal Length Monitoring Reticle ", SPIE Conference Proceedings 1999, Vol. 3, 051, pp. 448-4 55). The feature is that when shooting farther from the best focal length, the image printed by the reticle becomes asymmetric, and its image is displaced laterally. The analysis of these images can be based on the image Weights and measures tools, such as those used for gold-plated measurement. Another technique that determines the best focal length is line-shortening technology, also known as "schnitzlometry" (Cp · Ausschnitt), Lagers (Μ · Ε · Lagus), "Observing Forests and Finding Trees: A Critical Dimension (CD) Controls New Paths", Proceedings of the SPIE Conference, 1998 (v. 03, 332, 212-22). This method uses relatively large amounts. CD (~ 3 microns) line / space array configuration with two groups Columns are placed next to each other. When the structure is engraved by focal length and / or dose, the lines are shortened by themselves, and the array interval is enlarged. The measurement of this space can be made using image-based measurement tools, such as Gold-plated measurement method. One of the more widely used techniques to determine the best focal length is also known as the "Bossung" drawing method. When a critical dimension (CD) metrology tool, such as a CD-SEM or optical scatterometer, is

Page 8 200424499 V. Description of the invention (5) When the critical dimension is measured, the trend of the result is usually a parabolic-parabolic curve matching the trend of the critical dimension, and it is determined where the swash plate of the curve will be zero, and the most significant Best focal length. These curves are known = Plot for Mori. One of the advantages of the Parson method is that in addition to achieving the optimal focal length, the actual critical dimensions of the cubar process have also been quantified. However, this method is not always sound for some production processes, making it difficult to achieve a good focal length and difficult to implement in an automated manner. In addition, when this square is used in combination with CD-SEM, its measurement size may be affected by changing the side cutout of the line, which results in biased results. Soil unloading angle Optical scatterometers and related devices may use a variety of different types. Method-A single light source of a known wavelength is used, and Θ varies within a predetermined continuous performance range. Another method is to use different angles of incidence for the laser beam sources in the field angle. In this method, a kind of wide-spectrum incident light source is used, and there are :: the incident light radiated by the surrounding luminescence, and the incident angle of which can be optionally maintained—the optical element with a variable track phase is also known, this is the use of The optical two-piece produces a certain range of incident light phase, with a detector to detect the user's: light-emitting phase. In addition, it is also possible to use optical elements 1 with different polarization states to change the polarization state of the light from s to using optics and filters. The composition system may adjust the angle of incidence within a certain range φ, so that the :: source, the source can rotate around the target area, or the standard coherent source ^ = source or other radon sources. By using any of these different devices in combination or interactively, it is possible to know that a diffraction identification mark of a target can also be obtained. $ 样 & 200424499 V. Description of the Invention (6)-In addition to the light $ scatterometer device, there are other devices and methods that can determine the zero-order or south-order diffraction identification marks, which are reflected by using an irradiating light source ^ f or penetrates a periodic structure and is intercepted by a detector. In addition to optical scatterometers, these other devices and methods include ellipsometers and light reflection meters. In addition, it is further known that other radiation sources, such as X-rays, may be used to obtain non-light-based diffraction identification marks. A variety of sample targets are known in this art. A simple target that is often used is a diffraction grid, which is essentially a series of periodic lines. The typical width-to-space ratio is about 1: 1 to 1: 3, although it is known There are other ratios as well. A typical diffractive lattice bridge 'for example the ratio 丨: 3, may have a line width of 100 nanometers and an interval of 30 () nanometers', and the total distance (width plus interval) is 400 nanometers . The width and pitch are a function of the resolution of the stencil printing program; therefore, if the stencil printing program allows smaller widths and spacings, the width and spacing can be reduced equally. Diffraction techniques can take advantage of any feasible width and spacing, including those spiritually smaller than the width and spacing commonly used today. Double-period and other multi-periodic structures are also known, such as those disclosed publicly in US Patent Application Publication US 2000/0 131 055 issued September 19, 2002. Three-dimensional spatial grids or structures are also known, including those disclosed publicly in U.S. Patent Nos. 6,4 2,9,930. Therefore, the diffractive structure may have more than one period 'or be composed of elements other than lines and spaces, such as holes, squares, rods, and so on. It is further known that diffraction caused by a non-periodic structure, such as isolated feature appearances or series of feature appearances, can also be used as the method discussed herein or the scope of patent applications.

Page 10 200424499 V. Description of the invention (7) ----------------- Diffraction surname 4 Ji Guang, '" is a known pattern, typically scattered in In-die on wafer. PA soil / upper θ, ϊ > Know that in the current technology, multiple crystal grains (or exposure field technology, ^^ A) are used on a single wafer. The mother diffraction structure may be stenciled with different focal lengths, $ &T; For example, use different focal length settings or different exposure settings. At the same time, it is known that the focal length center can be determined by comparing the diffraction identification marks of the diffractive structures at different focal length positions with their theoretical molding libraries by using scatterometry and diffractive structures. The actual diffraction identification mark is compared with the chess pattern, and the key dimension (CD) is thus derived. Plot the key dimension values obtained in this way, and fit the results to the parabolic curve. This type of Bosen mapping has obvious limitations as discussed above. U.S. Patent Nos. 6, 4 2 9, 9 3 0 and 6, 6 0 6 1 52, as the same inventor of the present application, teaches a parameter measurement method related to a stencil printing device, which uses a method to provide a substrate. In the bottom step, the substrate includes a plurality of diffraction gratings formed on the substrate by the stencil printing process using a stencil printing device, and the diffraction grating includes a plurality of spaced-apart elements; a radiation source The benchmark tool is to measure the diffraction identification marks of at least three of the plurality of diffraction gratings; and determine the difference between these diffraction identification marks to determine a desired parameter of the so-called engraving printing device. In this method, the substrate may include a wafer. The method may further include a plurality of diffraction gratings, which are used for engraving printing devices with different known focal length settings; and determine diffraction gratings of two adjacent focal length settings, where the diffraction identification marks are between The difference is smaller than the difference of the diffraction identification marks between the diffraction gratings set by other adjacent focal lengths; thus, this parameter is the focal length of the engraving printing device.

Page 11 200424499 V. Description of Invention (8) Heart. That is to say, the international patent inventors' among the other marks teach that it will be compared by the diffraction library; the closest matching diffraction key dimension (CD) can be replaced by the cross section. This section can be centered on the adjacent focal plane itself. At the most relevant position on the section [content] The method of the present invention includes the mention of many numbers and many numbers in the majority field of the substrate screen; A field is a kind of field, and the structure forms many fields. When the optimal focal length is reached, the difference in diffraction recognition between adjacent focal length steps will reach a minimum. Application P (: Ίνυ3 02/3 2 39 4, as in this application, a parameter measurement method related to the engraving printing device, the diffraction identification mark measured by the structure and the theoretical model data of the Shen Dian diffraction structure The surface is determined by the cross section that can be obtained with the obtained diffractive structure model. This method is repeated by changing the focal length structure. Significantly changed parameters, such as from, the side wall surface, or the thickness of the resist, can be replaced by the calculated one. These parameters may be the area, volume, or ratio of the maximum cross-sectional area obtained from non-geometry and focal length trends, the numerical difference in the cross-sectional area of each phase structure, or the cross-section used to map the focal distance. Here In other examples, the focal length and the friend # coincide with the withdrawal line, and the point of the slope is zero ^: In t1, the curve-fitting combination is not required, and the center of the focal length product is small or maximum. 1 and a quarter version Relevant parameters of the printing equipment in each field: semiconductor wafers, step 3 has been exposed at different focal lengths, = the plate printing program uses the engraved printing; t, each chain is used to count each diffraction mind and body " & Basic The tool set which is positioned; the amount of its diffraction identification flag, the number of the number of diffraction region junction%

200424499

Measure the variability of the acquired radiographic identification marks; and compare with the number of such fields. This = degeneration, in order to determine a desired characteristic of the engraving printing equipment. Equation 1 shot variability may be mono-periodic, bi-periodic, multi-week. ▲ non-periodic structure, including grille . This source is a basic tool. It is best to include a light source as the basic system. -It is to include: or more incident laser beam source,-a kind of light detection =, beam focused and scanned through a certain range. Angle of incidence, and all. ί, to detect the diffraction identification formed by the entire measurement angle, the tool can optionally include a scatterometer that is analyzed by angle-division. In addition, the light is concentrated: it includes an incident broad-spectrum light source, an optical system that detects light emission at a range of incident wavelengths, and a diffraction identification mark formed by a detector to cover the measured wavelengths of J-line. The tool can emit light with amplitude and binary = incident light source, and its components are to change the phase of the S and P polarized radiation, 'a phase P where an optical system focuses the light and enters within a certain range, and a detection The diffraction identification mark formed by the device can be measured according to the data of the ancient times, soil, and broadband. The diffraction identification mark can be optionally included with the phase; For the door, it can be used alone-can be stunned / 7 angle θ wavelength towel s,,, or other, or a separate type of phase measurement is optional. Diffraction identification type of the diffraction identification standard ^ order :, conductive, reflection order, or somewhere! Measurements. The desired parameter is preferably the center of focus

Page 13 200424499 V. Description of the invention (10) '-In the 疋 疋 agent, it is preferably determined by the value of the desired parameter associated with the field with the most variability of the diffraction identification mark. The decision of φ 4 can optionally include measuring the intensity range of its diffraction identification private number for each field, and its identification mark is obtained from a large number of diffraction identification marks of 7 in the field, or it can be selected separately One is to calculate the statistical measurement of the variability, such as the root mean square error of the diffraction identification mark. Alternatively, the decision step includes providing a theoretical diffraction identification information database generated by a theoretical diffraction structure; determining a best-fit theoretical theoretical identification for each measured diffraction identification mark in the information database. Correlate a selected appearance dimension of the best-fit theory diffraction identification mark with the measured diffraction identification mark; and measure for each field its diffraction with a large number located in the field Variability in selected appearance dimensions associated with the structure. The selected appearance size is preferably a critical dimension (CD), or may be selected as a cross-sectional area, a cross-sectional volume, or two or more appearances that provide a theoretical diffraction structure adapted to the theoretical diffraction identification mark. Product of dimensions. The determining step may optionally include measuring, for each field, a range of selected appearance dimensions associated with a plurality of diffractive structures measured within the% field, or alternatively, including calculating the statistic measurement of the variability , For example, the standard deviation of the external dimensions of the 亥 疋 selection. The method can optionally include forming a large number of diffractive structures at different known focal length settings and different known dose settings, and measuring the effect of its dose on the focal length. Among them, the large number of diffractive structures can optionally include differences from known Diffraction and structure sets with the same focal length. These sets are known as

Page 14 200424499 V. Description of the invention (11) Different dose settings Latent image diffraction order. According to the present invention, the focus setting of the program-controlled printing equipment is adjusted to the brain as the basic control. There is an automatic measurement of the amount of degeneration. Diffraction recognition. The selected field is preferably the focus of the variability. The invention also includes a method in which a series of tools in a field domain are used to measure the structure of a diffractive structure obtained from a diffractive structure compared with those of a desired reference engraving printing device. The structure of the above method, and the substrate can be arbitrarily shot structure can not be subjected to any place. It is further a kind of printing equipment in a engraving. According to the above method, the engraving printing uses an autofocus control system method freely. $ The value of the coke control system or coke control system. Some pre-adjusted adjustments have been previously tested by the system located in the category. It is a variable number that is exposed on a large number of diffraction array wafers and is mostly exposed to a certain identification mark. At least one of the methods is denatured. The method can include steps; and the distance from the center, which can include a focal distance within the development range, to determine the focal length of the device at the moment, including at least one related to the minimum obtainable structure, and the good thing is, The input of the fake printing set includes the degeneration in the selected field. It is best to locate the structure of the control-limiting printing device with a fixed focal length and the same step of the light, and to measure the center of the time with a radiant diffraction. The highest degree is in one of the engraving fields; it also identifies each shot in order to control, which preferably includes additional parameters, and the best way to control the degeneration. The engraving printing equipment is based on a certain shot source. Diffraction is determined by a large number of comparison devices that adjust the circle in a theoretical way. The circle on a wafer determines its variability; the step outside the engraving printing is to respond to the crystal and to experience or

Page 15 200424499 V. Description of the invention (12) The variability limit determined is compared to the focal length or dose. These diffractive structures are preferred * The parameters preferably include sexual, multi-periodic, or non-periodic early, and periodic, double-periodic circles preferably include semiconductor wafers. Jing Jing 'is, for example, a grill. The crystals and the radiation source are basic and original tools, and it is preferable to include a laser light source as a basic system to focus the laser beam into two incident laser beam sources, one kind of light and one kind of detection. The device detects the angle of incidence, the angle of incidence of a certain range, and the log. This tool can optionally identify the target of diffraction formed by the angle of the person. The tool includes a scatterometer with two-angle division. In addition, the light can be focused and a wide-spectrum light source can be selected in a certain range, an optical system to detect the entire measurement wave and Changwu light, and a detector to optionally include an incident / infrared, and radiant identification mark. . The tool can have both amplitude and phase, one of which consists of changing the S and p polarization, and the incident phase emits light, and the _insert system, which focuses the light to a certain range of phases. Detect the diffraction identification mark formed by the detection according to the above method to measure the wide spectrum (or, in addition, the identification mark when the diffraction is used can be optionally measured with a single phase, and operate on a single phase Wavelength) towel field radiation source is the basic working degree Θ or a certain fixed sweeping sound fixed angle, a variable incident angle wavelength radiation source is the basic working 2 ', or a separate type is more casually- A kind of reflection type: 5 C, the diffraction identification mark can be a diffraction identification mark of order, and. A measure of chirp, reflection order, or higher. What you want is general light scattering or diffraction. The desired parameter is preferably the center of the focal length, or random.

Page 16 200424499 V. Description of the invention (13) The ground is a dose, and it is best determined by the measured value of the desired parameter associated with the field having the smallest variability of the diffraction identification mark. This determination step may optionally include measuring the intensity range of the diffraction identification mark for each wafer, and the identification mark is obtained from a plurality of diffraction identification marks measured on the wafer located in the field, or alternatively This is a statistical measurement that accounts for the variability, such as the root mean square error of the diffraction identification mark. Alternatively, the determining step includes the theoretical diffraction identification mark information database generated by deconstruction; determining a best-fit theoretical diffraction identification mark for each measured diffraction identification mark in the information library; A selected appearance dimension of the best-fit theory diffraction identification mark is associated with the measured diffraction identification mark; and it is determined for each wafer that it is related to a large number of diffractive structures located on the wafer in the field. Variability of selected external dimensions. The selected appearance size is preferably a critical size, or it may be selected as a cross-sectional area, a cross-sectional volume, or a g product of two or more appearance sizes providing a theoretical diffraction structure adapted to the theoretical implant identification mark. The determining step may optionally include measuring a range of selected appearance dimensions associated with a plurality of digital diffraction structures on the wafer in the field of the wafer for each wafer, or alternatively, including calculating a unified value of the variability, For example, the standard deviation of the selected external dimensions. The diffractive structure can optionally contain latent structures, and the wafer can optionally not yet undergo a one-ton wheat procedure * τ 耵 ... The primary objective of the present invention is to provide a seed factory to measure the relevant parameters of the engraving equipment without Using an optical, ^ J-finger electron microscope

$ 17 2004200424499

(SEM) or microscopy-like weights and measures. Another purpose of this month is to provide a method for determining the center of a focal length by diffracting the identification marks of the best-fit theory based on the analysis of one of a series of fields of different focal distance diffraction structures. The diffraction structure contains But it is not limited to the diffraction grid; and the inter-field variability of the best-fit structure is used to determine the focal length center. Another purpose of this month is to provide a method for determining or measuring the relevant parameters of a printing block, including the center of focus, by using reflection

Or conductive diffraction methods to obtain some diffraction identification marks of the same focal length structure in some different focal length fields; and determine the amount of internal-field variation between such diffraction identification marks, or to provide the best Matching theory, the internal-field variation of a parameter derived from the theoretical model of the identification mark. Another object of the present invention is to provide a method for determining or measuring the relevant parameters of a block printing device, including the focal length center: Sun borrows any method to generate a diffraction identification mark and obtains a diffraction mark. The method includes but does not include: Limited to reflective or conductive angle-divider, variable wavelength, variable phase, variable polarization state or variable azimuth diffraction, or related

Combiner; its identification mark is the zeroth order or reflected diffraction order or higher order of any diffracted or scattered light. Another object of the present invention is to provide a method for deciding or measuring the relevant parameters of a lithographic printing equipment, using diffraction identification marks of any order at different focal length fields in a wafer or other substrate, including the zero order Or inverse or any diffractive or historically high order diffraction, whether positive or negative

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Or scattered light. The parameters of this development are similar to those of the microscope in the short-time brushing device of the present invention, which are related to the scope of use, etc .; are easy to see, or may be a combination of them. For example, the “part of the present invention can be implemented in the field using a special method”. The advantage is that the optical weighing and weighing workforce is more common, which has a stepper. The other projects will be followed by those general exercise books. Attached exclusive and obtained. ”, Allowed to measure on the printing plate, scanning electron microscope (SEM) or the like. Provides a method and equipment that allows the known method to be cheaper and obtain the results of the engraving, including the focal length center. , Advantages and new features, as well as more detailed descriptions in the future, and it will be obvious for those skilled in the art to pass the following checks. The object of the present invention and the means and tools indicated in the Uli application park and the method and equipment provided by the present invention are for measuring the relevant parameters of a printing plate printing equipment, and in a preferred embodiment, it is determining the focal length of a printing plate printing equipment center. In the light processing and development steps of a wafer processing procedure, it is critical and critical to determine the focal length center for a fixed dose. Furthermore, variations in dosage can increase the difficulty of determining this center. Lenses used for engraving tools have a very limited depth of focus, so maximum accuracy is required. When the lens is at a positive focal length, a sharp-cut photoresist image will be produced, and those who lack the correct focus will cause a false photoresist appearance, and usually a rougher sequence is created. At the center of the focal length, or at the optimal focal length, the repeatability and stability of the program are improved. / Kind of focus center

200424499

The method is public, and the focal length is also included for practical use (var i ab i parameter value group changes and changes between items. Decide on measurement, measurement words, nouns and other nouns. 1 Use of variability analysis on the application center The diffraction structure is based on the diffraction structure.

Hty) or the degree of change (the extent of the range, which is measured, including but not limited to the phase of which the degree of diffractive movement is consistent, measured, calculated, or calculated, or compared with its minimum variability "and the full specification of the noun here The consistency of the manufacturing process determined by the consistency of the field 'first given the scope of the following patent application, variation) means a quantity or calculated structures' contrasting with each other, and these terms can be compared with each other Denaturation is synonymous with consistency. Π Maximum Consistency is the same as that in the scope of the patent application. "Monitoring in the present invention. The monitoring of the invention. Meaning. The number of variable species or a person who desires to be different. This can be so decided For example, and can be interchanged with a engraving plate such as a mask, the bottom. In this way, the package is printed, but also called the optically engraved master image, also known as the sequence, one or will be produced on whether the wafer is Negative anti-material materials brushing device is used to transfer a pattern to the general light enclosing other lithographers as a mask or more specified wafers. Further processing can be It is used to refer to any device that uses a printing method to print onto a substrate. It is called an anti-corrosive coating system in the optical reticle. For example, a photoresist type engraving system is used to apply electroprinting to a wafer, and the agent will be coated and baked as required. Usually, the image is not dissolved, for example, it is inserted into the lining type engraving printing. The road type is used in this circuit. In this process, it is used as the anti-worm or as the

5. Description of the invention (17) Chemical u of anti-I insect developer, silver agent usually dissolves. Once used :::; becomes soluble when =. Becomes insoluble when passing by light. II Selective exposure of the chemical product, but exposed to a part of the area and exclude other parts of the square resist layer to produce the circuit or other structures =, 1, can be selectively exposed in the resist film layer The law system is achieved by a masking mask in the printing method. 'This selection system achieves the action of illuminating light toward the shadow; the typical representative method layer. Mosquito shield, and project the transmitted image to the anti-money film

It is known that ::::: printing devices include steppers and scanners, or other structures: picture-scanning seedling device; it is used to connect-circuits. One Code :: [The mask pattern is projected onto the wafer coated with anti-agent, and the second stepper includes a reduction lens and a light emitter, a laser "LiLi round mirror stage, and a reticle optical standard. The linear mirror stage, | wafer box parallel tongue stepper adopts the positive and negative compensation methods, and adopts the step-repeat form or step-scan form, or both.

Those who use plate printing are-series of diffractive structures to clarify, ~~ = Yu Yiyue or other substrates. In the simplest way, $ 制 从 —He shoot structure is any structure or image with a engraving printing tool. 2 T = Second, it produces a kind of refractive index space relative to the incident light intensity. The change in the% refractive index may be due to physical differences or chemical differences. ^ The difference is that it includes photoresistance or other changes in the printing method of engraving. I envy you to use a certain material with a refractive index to combine with air. Another example is a χΐ-shaped optical diffraction grid, or a substance bound to other substances

Page 21 200424499 V. Description of the Invention (18) — Co-author. Chemical differences include wafers that have a diffraction chirp of optical resist exposure, such as a grid ' where the resist has not been developed. In this case, the anti- # agent still exists, but the developed part is different, which results in a diffractive structure composed of changes in the anti-phase. This periodic change is obtained by the structure or, periodically. A diffractive structure may have a single pre-energy or be a bi-periodic or may be 乂, can be marked with a column or eyelet:,! Through the diffraction grating, for example, the direction has its periodicity 72: square structure ', which is in the χ direction and γ square structure. -Kind of no ;: two and single, single-ϊ: diffractive structures that do not have periodicity in the χ direction or u direction, such as ⑨, are-:, or a single rectangular hibiscus structure with larger 疋. Similarly, the above-mentioned diffractive junction; ^ J = more heterogeneous)), and the = system repeatedly appears multiple times (-usually 10 or the diffractive structure is therefore wrapped several times (for example, two or three times). Metal gratings and Suntar ’s membrane stacking grille and diffraction grille are representative of: '^: Known grille. One tube is also useful if it is about 1: For example, the ratio of 1: 3 is possible. It has 100 superficial windings = ... The width and spacing can be changed significantly again: / card :; Liu Nai's resolution ability of this printing plate cluster. Part of it depends on the implementation of the present invention, a diffractive structure system (19) Diffraction identification mark. Diffraction generates 'such as optical scatterometer, uses optical technology such as scatter, reflectometry, sub-test' and uses any technique. Diffraction sources generated by radiation are basic tools. Diffraction sources are basic tools. It is possible that the identification marks of diffraction other than visible light are reflected by the anti-line and reflected. Therefore, the scatterometer generates the angle of incidence Θ at a predetermined value. Dingzhilianzhi can be used in this light-method Θ. In another source, and the incident light is selectively maintained by Θ using a range of incident identification ellipsoidal spectrophotometer photomicroscopy, and the typical example is to identify the typical light such as light such as X-ray Mode diffraction is used to recognize the intensity of a single continuous range of line. For a method of incident light, it can be measured by an instrument or optics, or an interference surface measurement such as an angle or a sign. It represents that the source being collected is the basic ray source. Different marks can be changed within the known wavelength. With the reflection angle beam source, Kerry, any of the following types of instruments, such as reflection measurement, polarization, or spectroscopic spectrum analysis, can be used to make polar measurement reflections. Any device installed here is classified as a type of user; however, in some implementations, the ray moonlight is used as an angle of the light source to describe the degree of rotation caused by the use of an incident width. A certain wavelength is set. A phase source with a variable phase is emitted, and the light source also has a detector to detect the visible light amplitude. In the case of the radiation source, such as the photometric division, Incident identification target. In the alternative, the incident angle of different spectrum light is known, its diffraction phase. Variable polarization light source is also known, it uses a range of polarization from S to p component Or p to s components. It is also possible to adjust the angle of incidence within a range Φ to cause the light source to rotate around the diffractive structure 'or alternatively to rotate the diffractive structure relative to the light source. Use any of these different devices' And the combination or permutation among them may be possible

Page 23 200424499 V. Description of the invention (20) It is known that diffraction identification targets with known diffraction structures can be obtained. In general, the detected light intensity can be plotted for at least one variable parameter, such as the incident angle Θ, the wavelength of the incident light, the phase of the incident light, the scanning angle φ, or the like. The diffraction identification mark may show a diffraction order of the zeroth order or reflection, or may show any higher diffraction order, or may be a measurement value of the general light diffraction or scattering. It is also possible or foreseeable that it is a conductive mode that can be used to generate a certain diffraction identification mark, such as using an X-ray radiation source as a component of which the radiation source is a basic tool. In one embodiment of the present invention, a theoretical information library of diffractive structures and corresponding theoretical diffraction identification marks is generated, and the theoretical diffraction identification marks based on the theoretical diffractive structure are compared with measured diffractions. Identification mark, comparison. This can be done by any of different methods. In a certain method, the actual information base of a theoretical output signal is generated based on the specified parameters of the variables. This information database may be generated before the actual measurement diffraction identification mark, or it may be generated in the private sequence where the measurement diffraction identification mark is adapted to the theoretical diffraction identification mark. Therefore, if used for this purpose, a theoretical information database includes a theoretical information database that is generated independently of the measurement of diffraction identification marks, and a theoretical π best guess based on the geometric shape of the measured structure. The theoretical information base generated by the calculation results; and iterative comparison with the changed parameter structure to determine the best fit. The diffraction identification marks and theoretical information base may also be generated empirically, for example, by collecting diffraction identification marks of diffractive structures whose structures have dimensions measured in other ways. The information base can be optionally deleted by removing certain signals, and its signals can be correctly expressed through the internal difference of other signals in the reference group. The information

Page 24 200424499

V. Description of the invention (21) The index of the library can be generated by similarly associating each identifier with one or more index functions, and then sorting the indexes according to the degree of the correlation. The construction or generation of this type of browsing information base, and its optimization methods, are well known in terms of technology. In one method

A rigorous theoretical model based on Maxwell's equation is the predictive properties of optical signals used to calculate diffractive structures, such as diffraction identification marks, as a function of diffractive structure parameters. In this process, a set of experimental values with this diffractive structure parameter is selected. Then, based on these values, a computer-model that can represent the parameters of the diffractive structure, including its optical material and geometry, was established. The interaction between the diffractive structure and the luminous radiation is simulated numerically to calculate a predicted diffraction identification mark. Any kind of trial optimization algorithm can be used to adjust the parameter values of the diffraction identification mark, and iterate through the program to minimize the difference between the measured and predicted diffraction identification marks. In order to get the best fit. The U.S. federal issued patent application number US 2 0 02/0 0 46 0 0 8 discloses a database method for structural identification, and the U.S. federal issued patent application number US 20 0 2/0 0 3 8 1 9 6 a way. Similarly, the U.S. federal issued patent application number US 2 0 2/0 1 3 5 78 3 discloses various methods of using the theoretical information library, as the U.S. federal issued patent application number US 2 0 2 / 〇〇3 8 1 9 6 —like. The grating or diffractive structure parameters that may be used in the theoretical information database include any parameters that can be used as models for the model, including elements such as: • The critical dimension (CD) degree at the bottom and / or top of the structure Or thickness, such as the height or thickness of a line, post, or other structure

Page 25

200424499 V. Description of the invention (22) The total height of a range defined by a diffraction identification mark. Structure shape, such as rectangular, trapezoidal, triangular, geometric shape, or the radius of curvature of the bottom and / or top of the area. The number of materials in the width of a periodic line or other structure of a grid, including its different stacking parameters, the material parameters of the substrate on which the structure is placed, such as a film, and the film layer under the structure The refraction coefficient is weighted by the value of the relative contribution of, for example, ":" or "average" at a specified position, or the information base model usually does not result in clear ::::: cross focus configuration Choice of configuration and theoretical model. At the same time, depending on the nature of the change. So it may be quick: the change of the focal length may include the film thickness of the determined section and look = 丄 the theoretical information, such as the constant period of light across the section. This may be more complicated, such as the contribution of the film thickness to the area of the grid and the cross-section of the film, the optical constant of the material n (considering the introduction of films and patterns. Weighting. The theoretical model is in the present invention In one embodiment, the cross-sectional area is identified by the diffraction identification mark of the theoretical diffraction Q.

The page is round or thick and the key size, etc. Theoretical scatterometer, which can cause the library f energy package may have a simple cross-sectional area ☆ The k-type may also be compared after the identification of the sign! 200424499 V. Description of the invention (23) The best fit theory diffraction identification sign Within the meaning of the best product of the best-fit structure. In one embodiment, the cross-sectional area is a product of a critical dimension and a height. In another section volume, such as critical dimensions, high. However, if applied to this, the section area has an undefined shape; that is, the section area can be a product of structural parameters, including but not limited to the examples. The cross-sectional area includes critical dimensions. If applied to this, the so-called at least two-derived mathematical operations or operations, including mathematical operations including the method, and optional operations. A wide variety of theoretical models For example, the definition of a rectangular grid is: Sectional area = Η · W (1) where Η is the grid height and w is the grid width. In order to improve its accuracy, a trapezoidal model may be used. The equation for the section of the trapezoidal grille is added as the section area = Η · (W —H / tan AK2) where H is the lattice Grid height, w is the wide face angle at the bottom of the grid. Other, more complex shapes such as one. The cross-sectional area is less than > diffractive junctions. It is the cross-section of the embodiment. § In the embodiment, the degree and shape of the structure need to be the same as those mentioned above. And | Less another diffractive structural parameter includes but is not limited to at least ~ The first round 扉 can be used. The area of the grille is the area of the bait parameter, for example, the cross-sectional area is the product of the product. The geometric method is more street shot in a certain ~ real shot structure parameter. The product is the theoretical model including the multiplication of two kinds of mathematics to determine the formula :: the center of the focal length of the stepping machine. The size of a soil corner. Decided, ’and Α is the trapezoidal side wall.

Page 27, 200424499, Description of the Invention (24) Stereo or S-shaped contour profile, or other customized contour profiles designated by the user may also be used to generate theoretical models. More complex shapes require more complex equations to represent the shape of the grid in cross-sectional area. The three-dimensional spatial structure may also be divided in a similar way. For three-dimensional structures μ. 'A measure of this section is the section volume. For example, a 2-accessible hole model is assumed to be a perfect circle in the X-axis and γ-axis directions, °, and a 90 ° uninterrupted side wall surface of the ΆZ-axis. Think of the cylinders as 'different' to produce _ kinds of cross-sectional volumes.

It can also be seen that a completely non-geometric section may also be used. The so-called cross section may be a parameter, such as the critical dimension, the product of one or more uniform, the number of lings, and other parameters such as material parameters, weighted or equal production, angle measurement, optical properties, curvature, or Others, etc. The: Use it in a way that is similar to the cross-sectional area or volume. Standard 2: The cross section of the identification mark for the measurement of the diffraction identification method is:

It can include a suitable identification of the measured diffraction identification mark. The theory contained in the existing information library revolves around the use of a defined beam to make chromium. For example, to use various adaptive algorithms. In another embodiment, the most appropriate =, a best fit can be selected. Recognize camphor in a certain theoretical diffraction, including. Interpolation of Bayesian Library to obtain that there is no two before the internal difference i 0, so that the theoretical diffraction identification marks the possible numbers, based on a flat description included in the information i Z and additionally including the calculation of the relevant model a theory Sampling of theoretical diffraction identification marks of diffraction identification clubs comes to ___ 75 ... Thus, any

200424499 V. Description of the invention (25) The identification mark pair technology, regardless of the best fit. The diffraction mask forms a masking mode, and the structural requirements of the masking mode are not only on the anti-jam layer of the masking mode, but also between the lens or the money layer, and also exposed to the radiation, a potential surface of the resist Changes, so it can be used to confirm or adapt to the theoretical diffraction identification mark or how to obtain a 'may be used here to determine an adaptation or an embodiment, the baking of _ One layer of the anti-money agent sequence, the production base material is exposed but 'used to resist the development of the remaining layer, partially or negatively generated the resistance, if the invention does not show the structure of the code has an invisible, large side, and The anti-other light can be selected or applied to the image, which can be used to produce anti-corrosion. In this procedure, the method of removing the anti-insecticide sacrifice layer is affected by other membranes, or the structure is transparent and small, and the structure of the surname is systematically set enough to resist the change of the remaining science. The layer has an additional implementation option. The remarkably long-lasting, that is, the device may conform to a resist-transparent area pattern. The masking mode is formed in the energy layer of the masking source which can be inserted into the radiation source. In the counter-example of chemistry, the shadow program that is the removal of the chemical manifestation is also placed in the region or the empty anti-layer layer, and the domain is actually generated on the manifested substance, and as desired. The other side of a radiation source's shape and air mold is placed in a hood and mask to allow anti-layer production. The potentially anti-reflective layer within the reflective identification target wafer can be accepted, or the more resistant layer can be shadowed, and the decision can be classified as a room and can follow it. Diffraction grating shadow. In the same way, the desired diffraction projection is projected to the top. , A module and the reactance. When the exposure changes the 4k image, the substitution ratio is changed. In a multi-component dissolution and development process after an actual exposure, the resist is intentionally lined with a positive process, and may be coated.

200424499 V. Inventor (26) generally describes a type that may be used, including line sources, including electron beams. The focal length is the total quantitative distance of any stepper or similar engraved or radiant energy. The resulting imaging is good, resulting in 'dose and focal length including astigmatism, orientation of field curvature, and so on. K foot is about 0.15 to large 0 · 4 0 to about 1. 5 micro The effective operation of a dose of tf in the wafer processing process is determined by the lens at the center of the lens. The lens has a focal angle of $ °, and the lack of correct alignment + + points also significantly improves the $ fan decision after any 7 The function used to determine whether the lens contains optical methods, such as generating phase shift exposure, and the printing function of the engraved printing plate must be right-a kind of external factor, mirror. A typical focal length of about 1 · 25 meters becomes in-process light. Difficulty. Depth of focus. Focal distance. Nishiji. The focus is on the program. Various areas are not used. ; And the charcoal / to limit the quality of the product also affects the production of micron ’〇 〇 center has a key resistance to exposure. Used for very common methods that will produce reproducible self-resolving crystals that cause nothing, the use of modes, etc. One of the key parameters is the focal length and focal depth depth, or the focal length that can be used in the fixed exposure field of the lens. The focal length and focal length, and the depth of focus of the wafer stage can be used with the wafer stepper. Decide on cause, example steps. Stepper limit, the renaturation of the contour ratio function. The dynamic focus circle is to maintain the electrical and electronic characteristics at a certain step, such as dose variation and other engraving, so that a sharper photoresistance profile is required. Once the focal length is uniform or fixed. Content method and any method of various radiation numbers, including the dose, to the point of the target. Natural depth; its and Y-directions have resolutions from about engraving into the machine for increased degree of printing. At the focal length, the structure is available. These systems are pressure sensing.

Page 30 200424499

V. Description of the invention (27) The device method, for example, cannot be used to determine the focus while maintaining. In typical sisters, a lens aberration # is added for a kind of engraving. The optical system, the diffractive structure with the same focal length other than the point where the distortion becomes more and more, will pass through the focal point in a priority real field 20 series using the wafer stepper, and each field 20 system preferably has a best distance value A number of initial zero-focal-point positions that contain zero-focal-length positions are consistent, often appear at the point of focus, or the focal lengths do not match. The order of the numbers of the displayed focal lengths may also be the same as in Figure 1A. The best compressed air in each field. However, these systems and structures focus on maintaining the lens-to-wafer distance. The focal length center must be determined on a regular basis. Common devices operate every six hours or so. t Distortion is important as it moves away from the center to the edge > the further away from the focal length, regardless of the positive or negative direction. In this way, if some lenses are projected on the bin-valued projectors, then they are distributed over the entire field of those lenses. Those projected on the focal point exhibit greater variability: In the embodiment, as shown in FIG. 1A, A series of separated fields are exposed or printed, preferably by a fixed dose throughout a wafer or other substrate 1Q. Expose at a different focal length value; these produce a series of focal length centers. In the example of FIG. 1A, the amount of focus deviation is represented by the number displayed on each field 20. The placement is arbitrarily selected, or randomly selected to correspond to a certain physics such as the top position of the anti-money layer. Since the optimal focal length passes some distance into the anti-surname layer ', the real center of the optimal focal length, it is very likely that the actual number of positions from the initial zero focal length will not be understood as limiting. This number is greater than +0.4 microns or less than ~ 0.4 microns. These are different fields described by which field is projected at which focal length deviation. Is a diffractive structure separated by a large number of 3 0, 3 0, so

Page 31 200424499 V. Description of the invention (28) For example, the structure of the diffraction grille, it is best to be the eighth prince, the general manager and the general manager. Fig. 1B shows that a certain% field has 25 diffractive structures 30, 30, and 5 x 5 = two. However, 'any number of structures may be used; Γ: Γ field field 20 average distributed. Optionally, the field may be formed within a grid, and the measurement as described below is based on the large grid, which is done at one or two points; or it is a combination of the two, where Ϊ :: ΐ: Large grids, each of which is tied to a different diffractive structure 30, 3 " repeating or periodic structure or non-periodic shape but capable of diffractive radiation within the grid; and it may be One-dimensional, such as a common grid with lines and spaces, or three-dimensional two, such as holes, poles or more complex structures. It is best to include the real structure which is being fabricated on each die on the wafer 2. Using a radiation source as a basic tool can be used for light scatterometer measurement =, each, diffractive structure 30, 30, or a sample determined by it, that is, to be measured to obtain a diffraction identification at a fixed dose Sign. In a preferred embodiment, each diffractive structure is compared with a wagon Λ library of diffraction identification marks, and each identification mark has a known appearance. One is that the match is found between the diffraction identification mark of each experiment and a theoretical diffraction identification 2 log, and a selected appearance size associated with the best fit theoretical model is assigned to each Diffraction structure 30, 30. The selected appearance size may include a single shape appearance, such as a key size (e.g., measured in nanometers), or a combination of appearances to form a section (as defined above). This selected aspect size will vary depending on the diffraction

Page 32 200424499

Structure 3 〇 π »α w. Rather than the same. Preferably, the 1-σ standard deviation of the fixed appearance size, which is the diffractive structure 3 0 卩 η, * > 'within 20 of each field, is then calculated. In addition to 1-σ shifting, a consistent measurement using ^ & quasi deviation may also be used to make ^ ', including but not limited to the overall range of the selected appearance size for each field minus the largest) or Other statistical or mathematical methods to varying degrees. " Heilien Corruption Information Library, used to determine the cross-section, may use a model with a simple 1 rectangular shape, or use more complex shapes such as trapezoid, trapezoid with round edges, Gaussia η or S Contour profile, or other contour profile specified by the user. The theoretical information base may also take into account the layers and patterns below t. Those diffraction identification logs generated in a theoretical manner, which have known characteristics, are adapted to experimental data in order to obtain the program characteristics of theoretical prediction. More complex models can include the optical properties of the diffraction and texture, such as the optical η and k values, as well as the thickness of the mold layer below it; in order to make the focal length measurement a sum of the optical path. 9 The standard deviation (or the variability of diffraction marks) of the selected external dimensions of each field 20 is then plotted for the relative pitch of each field 20, as shown in Figure 2. Although the selected appearance size is the key size in this example, any appearance size 'or a combination of appearance sizes may be selected. Calibration: Set the focal length of the field with the smallest standard deviation of the size, that is: Meaning: the focal length, or the focal length center. You can choose as you like. The material curve can be used to combine the data plotted in Figure 2. The minimum value of the line and the line is determined, that is, the slope of the curve is intersecting and yielding. Then "Don't ask for q 7. In this case, you can

200424499 V. Description of the invention (30) The learner is that a variety of different distance points are used to obtain the focal length: = Learn, which can be used to measure the internal difference focus. It is known in the technology, and may be 2 of 1. These methods are existing as shown in Figure 2. The one with micrometers located at the center of the focal length may be different from the field of 20 exposure, which is in the field of -0.1 (〇 · 〇). For the purpose of gaining an inch of freedom, it is located at the position of zero focal length, etc., and the engraving printer: the giant adjustment, program control, or similar numerical system and the zero focal point may be reset by the method provided by the present invention. Device, the second implementation of the present invention is preferentially implemented in accordance with r. A selection parameter. In this case, it is necessary to use a library of tribunal information or a diffractive structure (or its arbitrary choice from all changes in a certain field or the degree of consistency is determined. It is necessary to compare these diffractions with the identification mark. It is determined by the identification mark: 5 can be wrongly judged by the visual method and can not be directly measured 2: f2 This method requires the operation of any of various measurement methods or analysis methods y is relatively slow to the ground. Therefore, the U method includes, ㈣ Limited to, statistical methods: Examples ^ Mean square error method (MSE) or root mean square error method (RMSE), and other = Reed distance measurement methods. Such methods also include the average arithmetic, plus the 1000 average, the total number of averages Combining 2 other methods to describe the diffraction recognition log, the difference between its root mean square error and the root mean square error in a certain domain, the greater the variability, and the farther away from the center of focus. Alternatively, the overall or peak-to-peak range of the intensity of these identification marks can be used as a measure of variability. The dose of the center of focus should also be analyzed in a similar way. 200424499 V. Description of the invention (31 ) One series Born in a tool whose dose is a series of diffractions, it proposes other signs and methods. The amount of this tool is in the center of the focal length of the present invention. For the sake of limitation, the angle analysis has been divided into a series of steps with a series of identification marks. The radiation can be set to a line or a focal crystal of the focal distance. The ray consists of a basic structure that uses divergence or cuts, such as derivation and surrounds the center of the focal length, ',., Structure 30, the form consists of a structure with 5 = different focal diffraction structures, each of which is not a ,,,, The structure is then analyzed by the above analysis for each diffraction that is the source of the basic process. If the center of the focal length produced can be identified by μM diffraction, the effect of the dose is ~ . This way, you can find out and determine, _ 使 ΐ; distance-of-depth shadow plastic 种, η This A y 9 whichever is smaller can round non-uniformity, such as the tilt of the mirror table increased distribution in its crystal Round grid and grid variability in other fields The domain will still show that there is such an overall inconsistency in the grid in the field. It can be applied to systems that have radiation as the basis source and can be intercepted by reflection or penetration of a detector. In other words It can be said that the first scattering measurement method can be used for this radiation, light reflection, ellipsoidal measurement, or angle-analysis segmentation tools and / tools may be used. More tools 30 ,, the change from Fan Yuanbu knows A series of logos obtained from the agent, selected from the most healthy dose setting. The smallest comparison of lens image variability, the source structure of the present invention, any technology, polarized or spectrum is best included in production, comes with The result is the first analysis of the difference between the previous diffraction diffractions and the total focal length of the agent to determine the difference and astigmatism. After that, however, lies in variability. Looking for focal length measurers ’and can do things that include but are not measured or wavelength-what tools can

Page 35

200424499 V. Description of the invention (32) Those who generate a response such as a response to a tool parameter or a combination of tool parameters that cause a certain diffraction identification mark. Candidates for diffraction identification marks suitable for these technologies include, but are not limited to, photoresist grids, etched film stack grids, and metal grids. This technology. It can also be used to monitor shifts in production set focal length and / or dose and / or stack thickness. When monitoring the diffraction structure 30, 30, the diffraction

When selecting the parameter or degree of change of the identification mark, if the calculated standard deviation exceeds a certain value, the program may check the amount of drift. Changes in change indicate that a process transfer should be investigated. In addition, as a general procedural metrology measurement method, the structure across the entire wafer is measured, and the difference in diffraction identification marks can also be used as a weight-less method for wafer consistency. The low degree of change of the diffraction identification mark means that the process 1 ^: ^ ^ 1 ^ 7 —., The order consistency is good, the order consistency is insufficient, such as those in semiconductor manufacturing and their related mathematics. Poor match to experimental diffraction. The invention works as determined. The etched film stack of the invention

The higher the degree of change of the diffraction identification mark, the longer the distance is. This applies to many process steps and wafer types, such as stencil printing, etching, and metal clad steps. In use, various different filter models may be used to remove the possible adverse effects on the analysis of the focal length. The h-foot filters are measured using the theoretical diffraction identification mark and the degree of matching of different types of marks. Those who match well may be dragged out of this analysis. The method will look for the photoresist treatment process step as the first step. The best focal length for this step is extremely important. However, the = method can also be applied below the processing line, and the " best focal length " is set for the receiver and the metal grid, or

200424499 V. Description of the invention (33)-疋 is determined for the best remaining moment of π, δ Xuanfan carving procedure, and conditions. The method and equipment of the present invention may also be used for quality control testing, including analysis of the focal length center determined by other methods. This may be combined with a horny

-Analyzed by a light scattering meter, as described above, including its related X system, or other suitable devices that can be proud of > ^ & If an angle-analytical light scatterometer is used for the periodic structure, the diffraction identification mark is divided into different diffraction orders of angular positions and described by the grid equation: sin 9t + sin θη = ηλ / d (3 ) Is the wavelength of the incident light, and d is the space period or the distance between the gratings. Therefore, it can be seen that for the zeroth order or reflection, the incident angle is equal to the angular position of the diffraction order of the reflection. By the way, ^ diffraction order other than the reflection diffraction order 'or ordinary light scatterers may also be used, and its proper angular position is similar to the above-mentioned related system to generate other diffraction identification marks. , So that any mode that generates diffraction identification marks, regardless of the higher diffraction order of the reflected diffraction or ordinary light scattering or diffraction, may be used. Examples: ‘In a wavelength division device, the angle θ may change the wave η’ and solve the equation to obtain η.方法 The method and equipment of the present invention may also be used to determine the focal length center; the focal length center is adjusted in any way, including the use of: the system, and the method of the present invention is used to determine when an acceptable or optimal =

Page 37 200424499 V. Description of Invention (34) ___ The distance has been decided. This adjustment is done in a way known in the domain. This ;: = Dose change ’or other systems that can automatically or automatically determine and adjust i = outside can be used as the focal length center, at least one of which has two automatic focus control systems-the variability of consistency measurement. The system's input includes the selection system. The present invention can be used as a program control of the focal length. Therefore, in a certain embodiment, the Shiyi device and the controller computer. The i system: the brain is a function that can = determine a-program step-or variability. A field that determines the different parameter fields of the ^ y number, such as the two variables of diffraction identification: measurable variable: received at the time of electricity and can be planted with a brushing device, such as controlling a parameter of a certain program step. U plate printing can be provided as a feedback and feedback control technology, with 佟 ΐ :::!: parameters. For example, the field is internally variable: parameters; outside of the set limits, some of the program's step-required limit prediction parameters are modified, so the program can fall as much as you want, and the field can be described from then on. Internal variability is determined by one or the field where a certain parameter of the sequence of Daniel or Feng is modified and can be a bit; ij :: set limit ratio •. The internal variability of the field may be the variability of all the diffraction identification marks or the mouth of the person who is going to the field or the field of interest. Qi Page 38 200424499 Other signs > Generally speaking, in this step, this program directly changes the mid-field to key size of the program and directly monitors the subsequent processing steps. Fifth, the description of the invention (35) This diffraction is used, so the processing steps need to be processed. After a long period of time, a series of round processing to determine if the downstream processing process steps are already implied can imply that a certain change is not a quantifiable method. The testing device can accept acceptable restrictions, such as exposure. It is obvious on any wafer that the intra-domain variability has a harmful effect, which is similar to the intentional defocus setting and target degradation. Therefore, this method uses a crystal that is outside the latent map range and further uses the post-crystal and post-development processing procedures. The increase in the focal length of the processing results indicates the effect, which causes the distance to change in general. Off, but still mention the relevant and increase the field can be advanced-further used in the image to round the circle, after baking; what? This variable in the sample, although this provides a whole crystal inside a field. Example 1 According to the present invention, there are five fields exposed to different focal length values, in increments of 0 μm from -0.2 micron to +0.2 micron. between. Each field contains a 5x5 array of equally spaced diffractive structures, similar to that described in Figure 1B. Figures 3a-31 graphically show the critical dimensions (CD) of the diffractive structure in each field. Figure 4 shows the 1-σ Sigma) standard deviation of the critical dimensions of all 25 diffractive structures in each field. As mentioned above, the optimal focal length is achieved for this -0.1 micron focal length setting. Regarding real-time focus monitoring and program control 'it is important to be able to correct before the focus drift becomes too large. It is therefore advantageous to monitor the

200424499 V. Description of the invention (36). t ft ^ ^ 4-,, 4- The critical dimension of set S or other selected appearance dimensions, P ^ + order, " structure shows that the degree of change in its selected appearance dimensions is more than that of each :::: 25 One with a larger diffractive structure. For example, the change in the focal length of the selected external dimensions of a Hefei structure located in a certain field may be much larger than those located in the center of the field. Figure 5 simultaneously plots each field & ^ has 25 diffractive structures (ie the same data as shown in Figure 4). In the 昜 domain 5 X 5 array, there is only a 1-α standard deviation in the 5th row. . Xi Er has a larger slope for the five sets of L-structures than for 25 structures: the minimum value is easier to determine. It is expected that, due to the diffractive structure, it is difficult. "Compared with the monitoring of all 25 structures, the focal length: shift condition can be detected more quickly because of its steeper curve. This method is also used: 旎 is used to more accurately determine the focal length center of a case, #case is for ^ The change curve of the focal length derived from all diffractive structures in each field is close to flat, without a clear minimum Figure 6 is a graph of the same data as shown in Figure 4, but instead of plotting the standard deviation of all 25 CD values in each π domain, it plots the range of the "CD values (the maximum minus Go to the minimum, the unit is nanometer). It can be seen that both sets of data provide the same result, that is, its focal length center appears at the -0 micron bird distance position. Example 2 According to the second preferred embodiment discussed previously, FIG. 7 depicts diffraction identification marks generated by five spaced-apart diffraction structures in three fields shot at different focal lengths. In this case, it can be easily

Page 40 200424499 V. Description of the Invention (37) ___ It is judged that the degree of transformation of the shooting at a focal length of 0.0 micron is the smallest. The curve icon 2 in FIG. 7 indicates the range of variation of the recognition mark 'or the extended range. As you can see, the field identification mark of each field is strong. The field / person / minimum value taken at a focal length of 0.0 micron is relative to. This method can replace any of the ν :: Λ optimal focal lengths described above for those program-controlled and focal length drift monitors.例 ： A typical example of a program control application includes a mask mask engraved and manufactured using the same procedure. ^^ The circle is changed in the same way as time. Figure 8 depicts the change in size within the magic hour: = the degree of change in appearance size to size (in this case, the change in CD should be selected to measure the appearance 3, and it is best to include the previous method according to the present invention. Smaller ^ and tied to the lighting field in the center of focus). Since the X-ray method is used to mark the same structures and procedures for each wafer, the same structures and procedures are used to mark the same. Therefore, for each: = 2, the same masking is used. However, the focal length of the engraving printing tool "时 = 此: i ΐ ::! ΊίΓ: degeneration 'is shown in Figure 8. According to: the previous cognitive display nr. The degree of change is in the control, κ Γ is not too small, if there is any. If the change Cheng Chaochao, control limit, and has been considered as a problem, some-sales distance = may be used. In the data of this example, ',', on the 9th !!, Shi Hong sequence correction followed The data is measured on the 13th and 21st hours. In both cases, the ⑶ variable surface is on page 41 200424499 V. Description of the invention (38) :: Decided by the size of the next measurement, that is, reduced to everyone Familiar control limits. In this example, when the change data exceeds the control limit for the first time, the sequence correction is used. This is to avoid problems that may not exist, such as purely outside the control limits. Random changes, excessive corrections. Control rules Each program is different and the concept of controlling the focal length is the same as the field changes. The Ren /, and the use of the range Γ can be deduced for the application of the method according to the present invention. All diffractive structures in the field, or one of them, Z, is determined by the degree of change of the person. Among the changes, it is predetermined to identify the amount of change (for example, the mean square error = more than a certain type-correction: the best move It can be used. The difference is too early to indicate)) The modification method can be used to give feedback and feedback β to Ij, modify a parameter of a certain program step. For example, the% feedback control technology, With = exceeding the limit set theoretically or empirically: within the field =: sudden: a certain-parameter may be pre-missed according to the pre-missing 2 surroundings' then certain-: let the program fall back to the desired limit "Number and modify 'So: and i may use ~ a computer control system, i: the program can be automatically ^', to perform the identification of diffraction structures in the field: the diffraction identification will be collected and analyzed based on the amount of change, 軚 ~ Change analysis, and ▲ 1 — for this engraving printing ί: ί Various changes, such as dosage or: distance or more. Although: this matter is specifically described on these issues, other implementation examples may be the same. 2 implementation examples are detailed and modified. Changes that are bland and original for those familiar with the art

Page 42 ^ and intends to include all of these 200424499 V. Description of Inventions (39) These modifications and their equivalents are included in the scope of the additional patent application requirements. The full disclosures of all references, applications, patents and publications mentioned above are hereby incorporated by reference.

Page 43 200424499 Brief description of the drawings ^ The accompanying illustrations, etc., are included in the specification; they are used to illustrate one of the inventions and become one of the explanations for explaining the principles of the present invention. , Together with its text, one or more preferred embodiments of the invention are for the purpose of describing the present invention only. In the illustration: "'is not to be interpreted as limiting the present invention. Figure 1A depicts the generation of m-light; a certain name ® with some fields exposed at different focal lengths. Figure 1B depicts the field of Figure 1A. $ _ Figure 2 shows the diffractivity of each field, including some diffractive structures; the difference curve; the c " d value change of the standard partial range of the critical dimension (CD) of the structure: the basis of the drawing Figure 4 of the different fields in Example 1 of the present invention is based on the quantity curve in Example 1. The standard deviation of all CD measurement values in each region is shown in Figure 5 as the beginning of the curve fgj. ? Each field in Example 1 is more graphable ... The "quasi-deviation curve" of the wooden figure; curve i ;, according to the change amplitude of all measured cd values in each field in Example 1. Diffraction: 7 is not a qu : The figure shows that J is based on the result of the comparison with the car parent in the field of different focal lengths in Example 2; and the value. FIG. 8 is a graph illustrating a program-controlled quantity measurement according to Example 3. FIG.

Claims (1)

200424499 VI. Scope of patent application 1. A measurement includes providing a distance value to expose the engraving plate to a diffraction structure for each of the windings and a comparison. 2. If the structure is a single structure. 3. If the grid is included 4. As the half guide 5. As the basic 6. If the source is a base laser to detect the type of light contained in the next step, and the radiation source structure is measured to determine the field shot to identify these fields Please tear it off periodically. In the application for special wafers, please use the special tool beam focus test in the special tool kit to test the entire test -------- and the relevant parameters of the engraving printing equipment. Substrates with numerous digital fields, each of which does not contain numerous digital diffractive structures, which are formed on the substrate using a engraving printing process; ^ -based tools are numerous data in multiple digital fields Each of its diffraction identification marks; determines its variability as measured by a number of diffractive structures located in the field; and the variability associated with the field to determine the parameters of the engraving printing equipment. The method described in item 1 of the scope of interest 'wherein the diffraction junctions, bi-periodic, multi-periodic, or the method described in item 2 of the range of non-periodic secondary interests' wherein the scope of the diffraction structure The method described in item 1, wherein the substrate includes the method described in item 1 of the profit range, wherein the company includes a light source-based method U § The source of radiation is the item of interest range 1 The method described above, which includes a human laser beam source, ~ "'uses a light beam and scans a range of incident angles, and uses an optical system to identify the diffraction formed by measuring angles > f Page 45 200424499 6. Scope of patent application 7. The method described in item 6 of the scope of patent application, wherein the light source is a basic tool including a scatterometer that is analyzed by angle-division. 8. The method according to item 5 of the scope of patent application, wherein the light source is a basic tool and includes a plurality of digital laser beam sources. 9. The method according to item 5 of the scope of patent application, wherein the light source is a basic tool including an incident wide-spectrum light source, an optical system focuses the light and emits light at a range of incident wavelengths, and a detector to Detect the diffraction identification mark formed for the entire measurement wavelength. 10. The method according to item 5 of the scope of the patent application, wherein the light source is a basic tool including an incident light source whose constituent parts are those that change the amplitude and phase of the S and P polarizations, and an optical system converts the light Focus and emit light with a range of incident phases, and a detector to detect the phases of the formed diffraction identifiers. 11. The method as described in item 1 of the scope of patent application, wherein measuring a diffraction identification mark includes a phase measurement based on a broad-spectrum radiation source, which operates at a fixed angle, a certain Variable incident angle Θ or some variable scanning angle Φ. 12. The method as described in item 1 of the scope of patent application, wherein measuring a diffraction identification mark includes a single-wavelength radiation source as a basic tool for phase measurement, which operates at a fixed angle, a certain Variable incident angle Θ or some variable scanning angle Φ. 13. The method as described in item 1 of the scope of patent application, wherein measuring a diffraction identification mark comprises a phase measurement using a separate multi-wavelength radiation source as a basic tool. Page 46 200424499 6. Scope of Patent Application 14. The method described in item 1 of the scope of patent application, wherein the diffraction identification mark is a reflective diffraction identification mark. 15. The method as described in item 1 of the scope of patent application, wherein the diffraction identification mark is a conductive diffraction identification mark. 16. The method according to item 1 of the scope of patent application, wherein the diffraction identification mark is a reflection identification diffraction mark. 17. The method according to item 1 of the scope of patent application, wherein the diffraction identification mark is a higher-order diffraction identification mark. 18. The method according to item 1 of the scope of the patent application, wherein the diffraction identification mark is a measurement of a general amount of light scattering or diffraction. 19. The method as described in item 1 of the scope of patent application, wherein the desired parameter is the focal length center. 20. The method according to item 1 of the scope of the patent application, wherein the desired parameter is a dose. 21. The method as described in item 1 of the scope of patent application, wherein the value of the desired parameter of the engraving printing device is determined by the value of the desired parameter associated with the field having the smallest variability of the diffraction identification mark. 22. The method as described in item 1 of the patent application range, wherein the determining step includes measuring the intensity range of its diffraction identification mark for each field, and the identification mark is a diffraction measurement measured by a plurality of numbers located in the field The identification mark was obtained. 2 3. The method as described in item 1 of the scope of the patent application, wherein the determining step includes calculating a statistical measure of the variability. 24. The method according to item 23 of the scope of patent application, wherein the statistical measurement Page 47 200424499 VI. The number of patent applications is the diffraction 25. For example, if the applicant knows different diffraction structures, 26. For example, the structure includes # 套 组 随 所 27. If you apply for identification f & Patent Fan Yuan The focal length sets and determines the root mean square error of the patent range from different patent ranges that are unknown. The method described in item 1 further includes forming a large number of different dose settings and the known effect of the dose on the focal length. The method according to item 25, wherein the plurality of numbers are diffracted with the same focal length setting, and the dose setting is changed. The method according to item 1, wherein the determining step includes providing a theoretical diffraction identification mark information database generated by a theoretical diffractive structure; according to the principle of the best fit, the most relevant measurement is measured for each association The selection of 28. If the size is the key 29. If the size is applied for a break 30. If + please the size is a break 3 I #If you apply for the diffraction field of the theory of diffraction in the application library Determining Appearance Dimensions Patent Area Dimensions (CD) Patent Area Face Area. Patent scope Noodle volume. Each measured diffraction identification mark in the patent scope determines a unique t-state; it is related to a selected appearance size mark of the diffraction identification mark; and it is related to a large number of diffraction structures located in the field. The variability. The method of item 27, wherein the selected appearance The method of item 27, wherein the selected appearance The method of item 27, wherein the selected appearance The method of item 27, wherein the selected appearance 200424499 VI. Scope of patent application The dimension is the product of two or more external dimensions of the theoretical diffraction structure that matches the theoretical diffraction identification standard. 32. The method as described in item 27 of the scope of the patent application, wherein the determining step includes measuring, for each field, a range of selected appearance dimensions associated with a diffractive structure measured by a majority of the screen located in the field. 33. The method as described in item 27 of the scope of the patent application, wherein the determining step includes calculating a statistic measurement of its variability. 34. The method described in item 33 of the scope of patent application 'wherein the statistical measurement value is the standard deviation of the selected appearance size ° 35. The method described in item 1 of the scope of patent application' The diffractive structure includes a latent image diffractive structure. 36. The method as described in claim 1 of the scope of the patent application, wherein the substrate has not been subjected to a development process. 37. A program control method for a focal length center in a engraving printing device The method includes the following steps: / engraving printing Determine the focal length center of the device according to the method described in item 19 of the scope of patent application; and Adjust the focus setting of the engraving printing equipment to the determined center. < Focus moment 3 8 · The method as described in item 37 of the scope of patent application, wherein the adjustment system uses a computer-based control system. " " 疋 步 骒 3 9 · The method described in item 37 of the scope of patent application, wherein the copper 敕 includes an autofocus control system, of which at least ~ automatic two = step Lexie focus control Page 49 200424499 42. The method as described in item 40 of the scope of patent application, wherein if the variability exceeds a predetermined control limit, the engraved printing is adjusted. Sigh W < Jiao 43 · — The following steps are based on the method of program control in the engraving printing equipment. The method includes exposing a large number of diffractive structures with the engraving printing equipment on a series of wafers in a certain field. ; $ / In which a revolving source is used as the basic tool to measure the diffraction identification marks of various diffraction structures on a series of wafers in a certain field; for each wafer it is determined by the multiple diffraction structures Obtain the variability of the measured diffraction identification mark; and compare the variability associated with the wafers to control a desired parameter of the engraving printing equipment. 44. The method as described in item 43 of the scope of patent application, further comprising the step of adjusting at least one desired parameter of the stencil printing device in response to the comparative variability associated with the wafer. 4 5. The method as described in item 44 of the scope of patent application, wherein the adjusting step includes comparing with the variability limit determined empirically. 200424499 VI. Scope of patent application 46. The method described in item 44 of the scope of patent application, wherein the adjustment step includes a comparison with the variability limit determined theoretically. 47. The method as described in item 44 of the scope of patent application, wherein the at least one desired parameter comprises a focal length or a dose. 48. The method described in item 43 of the scope of patent application, wherein the diffractive structures are monocyclic, bi-periodic, multi-periodic, or non-periodic structures. 49. The method as described in claim 48, wherein the diffractive structures include a grid. 50. The method as described in item 43 of the scope of patent application, wherein the wafers include semiconductor wafers. 51. The method according to item 43 of the scope of the patent application, wherein the radiation source is a basic tool, and a light source is a basic tool. 5 2. The method according to item 51 of the scope of patent application, wherein the light source-based tool includes an incident laser beam source, an optical system focuses and scans the laser beam through a range of incident angles, and A detector to detect diffraction identification marks formed over the entire measurement angle. 53. The method according to item 52 of the scope of the patent application, wherein the light source-based tool includes a scatterometer based on angle-division analysis. 54. The method as described in item 51 of the scope of patent application, wherein the light source-based tool includes a plurality of digital laser beam sources. 55. The method described in claim 51 of the scope of patent application, wherein the light source-based tool includes an incident wide-spectrum light source, an optical system that focuses light and emits light at a range of incident wavelengths, and a detector P. 51 200424499, with: t ® urban shot identification. The detection method for the entire n skin length = method, which uses a light source μ. As described in item 5 of the patent application source, its constituent parts become basic tools including an incident chirped optical system to focus the light and For the amplitude and phase of the S and p polarizations, a detector is used to detect the phase formed by emitting light with a certain range of incident phases and diffraction identification marks. Method in which a certain incident angle Θ around a variable f or a certain 5 7 · As described in item 43 of the scope of the patent application, the phase identification of the source is a basic tool. The radio frequency identification mark consists of a wide-spectrum measurement and is operated at a fixed angle and a variable angle Φ. Method, in which a certain phase is measured. As described in Item 43 of the scope of the patent application, the phase-recognition target of a radiation source as a basic tool includes a single-wavelength field / variable incident angle ㊀ or bit measurement. And it operates at a certain fixed angle and a certain variable scanning angle Φ. Method, in which a certain winding is measured. 59. The radiation source is a basic tool as described in Item 43 of the scope of the patent application. The radiation identification mark includes a phase measurement using a separate multi-wave *. Method, wherein the diffraction identification 60. The mark as described in item 43 of the scope of patent application is a type of reflective diffraction identification mark. Method, wherein the diffraction identification 6 1 is a conductive diffraction identification method as described in item 43 of the patent application scope, wherein the diffraction identification 62 is as described in item 43 of the patent application scope The 'sign is a reflection order diffraction identification method, wherein the diffraction identification 63 is as described in item 43 of the scope of patent application. 200424499 VI. Scope of patent application The logo is a kind of 64. If the application is for a standard, the light is generally 6 6. If the application is for a crystal, the logo is obtained by many journals. 66. If the application includes the calculation of the possible 6 7 · If the application specific value is the diffraction higher order diffraction identification mark. The method described in item 43 of the profit range, wherein the diffraction identification line scatters or diffracts a certain measurement setting value of the method described in item 43. The circle measures its diffraction identification mark ^ strong f The number is located in the wafer in the field. The method of the determination described in item 43 is used to determine the range of the determination step. The method described in item 43 above is used. In the method described in item 6, the error of the root mean square (square of this statistical measurement) of the identification mark. 6 8. The inclusion method as described in item 43 of the scope of patent application, which provides a theoretical winding database generated by a theoretical diffractive structure; based on the best-fit theory, the best and the quantity are measured as Relevant crystal structures are associated with each other. 9. If you apply for a special dimension to identify the diffraction identification marks for each of the measured diffraction identifications in the ruler library; the diffraction identification marks of the adaptive theory diffraction identification marks are associated; and The β circle determines its variability with the selected external dimensions of the wafer located in the field. The method described in item 68 of the scope of interest ′ is the determination step in the dimension (C D). The target identification mark determines the most selected appearance size. Page 53 200424499 乂. Patent application scope 70. The method described in item 68 of the patent application scope, wherein the selected appearance size is a cross-sectional area. 71. The method as described in item 68 of the scope of patent application, wherein the selected appearance dimension is a cross-sectional volume. 7 2. The method as described in item 68 of the scope of patent application, wherein the selected appearance size is a product of two or more appearance sizes of a theoretical diffractive structure adapted to a theoretical diffraction identification mark. 7 3. The method as described in item 68 of the scope of patent application, wherein the determining step includes measuring, for each wafer, a range of selected appearance dimensions associated with a plurality of digital diffraction structures on the wafer located in the field. 74. The method as described in item 68 of the scope of the patent application, wherein the determining step includes calculating a statistical measurement of the variability. 75. The method as described in item 74 of the scope of patent application, wherein the measured value of the statistical value is the standard deviation of the selected appearance size. 〇 6. 6. As described in item 43 of the scope of patent application. Method, wherein the diffractive structure comprises a latent image diffractive structure. 77. The method of claim 43, wherein the wafer has not been subjected to a development process. Page 54