KR20010015473A - Method and system of multiple band uv light illumination of wafers for optical microscopy wafer inspection and metrology systems - Google Patents

Abstract

PURPOSE: A method and a system for multiband UV lighting of wafer for optical microscope wafer inspection and measurement system are provided to actualize the lighting of multiband UV which is technically adaptive to various applications, advantageous in cost, and hardly broken. CONSTITUTION: The system comprises a UV light source (such as Hg arc lamp) to generate a multiband UV light source having two UV narrow bands of 360-370nm and 398-407nm and a single visual narrow band of 427-434nm through broadband and discontinuous band filtering treatment. The optical microscope is characterized by a broadband objective system, a lighting path, and a tube lens, a camera, and a data processor.

Description

METHOD AND SYSTEM OF MULTIPLE BAND UV LIGHT ILLUMINATION OF WAFERS FOR OPTICAL MICROSCOPY WAFER INSPECTION AND METROLOGY SYSTEMS

Applied to wafer inspection and metrology systems, the present invention relates to illumination methods and systems used in optical microtechnology, and more particularly to methods of multi-band UV (ultraviolet) light illumination of wafers used in optical microtechnology wafer inspection and metrology systems. And to the system.

In the semiconductor industry, optical microtechnology wafer inspection and metrology systems are routinely used for research and fabrication of silicon based wafers. Application of optical microscopic wafer inspection and metrology systems allows close-up of the surface shape of the wafer, in particular the detection, resolution and properties for the measurement of defects, patterns, and other surface structures. Specific examples of applications of optical microscopic wafer inspection and metrology systems include the areas of wafer defect detection, optical overlay metrology, and optical CD (critical size) metrology and control. The nature of the wafer surface shape is very important in the quality control process applied along the successive steps of wafer fabrication. Moreover, due to the large resource consumption up to the manufacture of new wafers, and at the real production level, suitable optical microtechnology wafer inspection or metrology systems must be technically feasible and reliable to be useful in the production environment.

As used herein, the term 'CD' or 'critical size' refers to the smallest size of the structure on the wafer that is controllable during the fabrication process of the wafer. As used herein, the term 'pattern' refers to a planned or desired pattern, design, structure, or shape on a wafer having a measurable size, and the term 'defect' has a measurable size and the presence of an undesirable structure or shape. , Or imperfection of the wafer, such as the absence of a desired structure or shape. More specifically, current technology in the semiconductor industry uses 180 nm as the reference and critical size of wafer patterns. In addition, 'killer' defects are defects of sufficient size that directly damage or even destroy the function of certain wafers in the wafer. At present, defects are regularly classified as killer defects if they are half the size of the reference and critical size of 180 nm currently used, ie 90 nm. For metrology, the required precision is typically greater than 10% of the critical size, ie less than 20 nm. Clearly, it is critically important to have edge sensing capability as well as detect killer and other wafer defects early in the cycle of growing and manufacturing new wafers.

The particular method and system of illumination used in a particular wafer inspection or metrology system determines the overall quality of the results obtained from the wafer inspection or metrology system. Optical Microscopy Technology Current methods and systems of illumination applied to wafer inspection and metrology systems include the use of wideband white light illumination, single (narrow) band UV light illumination of wafers. Narrow bands of UV light are commonly known as being referred to as 'monochrome' for sufficiently narrow bands of wavelengths. The present invention consistently uses 'narrow band' and 'monochrome' UV light. White light illumination is referred to as lightband illumination of the branch light spectrum. Wafer inspection and metrology optical microscopy techniques include specially designed lamps (eg, lamps containing high or low pressure mercury vapor mixed with an inert gas), which lamps include narrowbands in the visible spectral range, for example. In addition to the other light spectra, a monochromatic UV light is generated having optical band white light in the visible spectral range of 400 to 800 nm and narrow band in the spectral range of 250 to 500 nm.

The type of illumination source used in an optical microscope is an important factor in determining image resolution, which is the image intensity, brightness, or intensity of light rays between objects [published by Campid University Press, 1998]. 6th edition of 'Principles of Optics: Electromagnetic Theory of Propagation and Diffraction of Light' by Born, Max, and Wolf, Mail As defined in the following] two dark objects or structures are resolved when reaching 0.707.

The results of the wafer image obtained by using an optical microscope for inspection or metrology of the wafer are inverted by diffraction, which is inverted by the wavelength of the light of a given illumination light source and the objects or structures (eg pattern or pattern) on the wafer surface. Defects). Here, the diffraction effect is considered as system noise that reduces the quality of the wafer image. For a given wafer surface shape, the degree of diffraction is a function of the microscopic optics (eg lens system or objective aperture) and the illumination spectrum (ie, white light versus UV light, light band versus monochromatic, illumination). Monochromatic UV light illumination of the wafer results in higher image resolution compared to the optical band white light illumination of the wafer, while monochromatic UV light illumination is known to have multiple objects known as patterns and / or defects in the vicinity of each other as compared to the optical band white light illumination or It produces a particularly significant diffraction effect on the wafer characterized by the structure.

Optical Microscopic Technology In wafer inspection and metrology systems, wafer defects near the wafer pattern or other wafer defects or even near the pattern (eg, inspection or metrology of wafer defects or clusters of patterns), depending on the actual goal of the procedure. Alternatively, it is always important to design a method and system of wafer illumination that enables proper detection of the pattern, resolution, and critical size measurements. In such cases, in addition to the standard image resolution of individual defects and patterns, the diffraction effect is very important in the image data to be interpreted. In addition to the commonly used single object or structure image resolutions, suitable features of the results of image analysis of wafers limited by the diffraction effect include the use of the term “system resolution” with units of distance, the first of the same wafer. Typically defined in the field of wafer inspection metrology techniques as the distance between a defect or pattern, and another defect or edge of the pattern, the precision of the detection or measurement of the first defect or pattern occurs due to the edge of another pattern or defect. Even in the presence of a diffraction effect, more specifically, for example, for a wafer defect detection system, the system resolution refers to the distance between the first detection on the same wafer and the edge of another defect or pattern. Therefore, the detectability of the first defect is statistically significant.

The numerical value of system resolution associated with a given method of wafer inspection system decreases with increasing system resolution with a distance unit such as, for example, nm, which can be resolved at a distance of 500 nm away from the edge of a pattern or another defect. By a defect is meant a method with a higher system resolution than how the defect is resolved at a larger distance 100 nm away from the edge of the pattern or another defect. The method with measurably increased system resolution utilizes wafer inspection or metrology methods and systems that reduce diffraction effects, thus effectively reducing the edge size of defects or patterns. Therefore, in order to properly design an effective method and system of wafer illumination for using a given optical microtechnology wafer inspection system, with respect to the image quality of the wafer characterized by multiple objects or structures (ie patterns, defects). ) Simultaneously consider the three resolutions associated with parameters such as single object or structure image resolution, 2) diffraction effect, and 3) system resolution and determine the optimal of the three resolutions with which the parameters are related.

Optical Microscopy Techniques Applying Wideband Illumination of Wafers In methods and systems of wafer inspection and metrology systems, it is well known that diffraction effects are measurably less comparable to methods of applying narrowband or monochromatic illumination of wafers. In fact, optical band illumination transforms a single object image into a Gaussian like envelope. This reduces the first diffraction order contrast and improves the total image contrast or system resolution as a result of comparison to monochromatic illumination that produces an image characterized by inclusion of more than one diffraction order contrast. For this reason, most current wafer inspection or metrology system methods and systems involve the use of wideband white light illumination of a wafer.

Several important illuminations exist with currently applied methods and systems of wafer illumination used for optical microtechnology wafer inspection or metrology systems. Although the current critical size of the wafer is about 180 nm, regular analysis of the wafer structure is reduced to about 90 nm for defect detection, including more than 10 nm for optical overlay applications. To date, methods and systems including wideband white light illumination for use in wafer inspection systems have been suitable for obtaining images of high quality and high system resolution. However, as wafer inspection and metrology techniques advance, the critical size is more subtle, and it is more difficult to maintain high single object or structure image resolution, and system resolution using optical band white light illumination of the wafer. As such, the illumination methods and systems used in optical microfabricated wafer inspection and metrology systems necessarily change from light band white light illumination to light source wafer illumination such as low wavelength, higher energy, UV light illumination. Do. Therefore, it is necessary and useful to have a method and system of illumination for use in optical microtechnology wafer inspection and metrology systems based on UV light sources.

For systems and methods of illumination involving the use of UV light sources, additional Jane is needed to overcome. For example, a single object or structure image resolution is 360 (eg, commonly used 360) compared to an optical band white light source for wafer illumination (e.g., characterized by a spectrum in the optical band wavelength range of 400 to 800 nm). By using a monochromatic UV light source (characterized by a narrowband wavelength range of from 370 nm). However, the diffraction effect increases simultaneously with the increasing energy of the illuminating light source, such as a monochromatic UV light source, resulting in noise in the data of the wafer image, thereby reducing the system resolution. This phenomenon occurs especially for wafers that are characterized by multiple defects and patterns near each other. Commonly used methods of eliminating or minimizing diffraction effects are readily applicable to current wafer inspection or metrology systems using monochromatic UV light sources. For example, interferometer techniques may be used, but interferometer techniques are very slow, low yield, and complex to implement. Furthermore, image processing techniques, such as deconvolving diffraction rings from images, are not practical for use as optical microtechnical inspection or metrology systems.

Optical Microwave Technology An ideal method and system of wafer illumination for use in wafer inspection and metrology systems is, for example, a wideband UV illumination of a wafer characterized by the use of a wideband UV light source having a spectrum in the range of 250 to 500 nm. Includes the use of. This optical band UV light source allows for effective change of single objects or structures into a Gaussian envelope, thereby reducing the interfering diffraction effect and higher system resolution. Unfortunately, although theoretically possible, a broad band UV light source has not been identified at present. Known UV light sources (eg, mercury arc lamps) exhibit narrow band monochromatic spectra (eg, 360-370 nm, 398-407 nm, etc.).

An approach to an ideal light band UV light source is to use multiple bands or wavelengths of known UV light sources for wafer illumination. In this case, the single object or structure resolution is superior to the resolution of the method comprising white light illumination, and the simultaneous diffraction effect is less than the diffraction effect observed in the image obtained by applying the method including a monochromatic UV light source. Therefore, it is required and useful to have a method and system of multi-band UV light illumination for use in optical microtechnology wafer inspection and metrology systems. Moreover, it is required and useful to have the same method and system of technically practicable, cost effective and reliable wafer illumination for regular application in wafer fabrication environments in wafer research or development environments.

FIELD OF THE INVENTION The present invention relates to a method and system of illumination for use in optical microtechnology as applied to wafer inspection and metrology systems, and more particularly to multiband UV ray illumination of wafers for use in optical microtechnology wafer inspection and metrology systems. Relates to a method and a system.

The method and system of multiband UV light illumination of the present invention is characterized by two narrow band ranges of UV light illumination spectra of 360 to 370 nm, 398 to 407 nm, and a visible light illumination spectrum of a single narrow band range of 427 to 434 nm. The branch is characterized by using a UV light source (eg a mercury arc lamp) to generate a multi-wavelength UV light source. In addition, the methods and apparatus of the present invention allow optical band focus systems to pass multiband UV light through an optical band UV illumination path and collect image reflections and scatter from the wafer surface, and to focus and optically reflect the image reflections. Provided are wafer devices or metrology systems with optics including, but not limited to, optical band tube lenses for scattering on sensitive camera surfaces. Moreover, specially input data processing algorithms are used for the processing of wafer images obtained by using the methods and systems of the present invention.

The implementation of the method and system of multiband UV light illumination of a wafer for an optical microtechnology wafer inspection and metrology system of the present invention is significant and measurable at a single object or structure resolution compared to methods and systems featuring optical band white light illumination. This results in a significant and measurable overall system resolution of the wafer image as compared to methods and systems that feature monochromatic UV light illumination without radiation damage to the wafer. The methods and systems of the present invention are directly applicable to wafer fabrication environments, including application to quality control systems used at various stages of wafer fabrication. Improvements in system resolution of wafer images are critical to the technological advances currently occurring in wafer development and to fabrication in the semiconductor industry.

One preferred embodiment of the method of multiband UV light illumination of a wafer for an optical microtechnology wafer inspection and metrology system of the present invention features the following main steps. (1) initializing an optical microtechnology system for wafer inspection or metrology, (a) providing an optical microscope having an optical band objective lens system, and (b) preferably enlarging the optical band objective lens system. Selecting a step; (2) optimizing an optical microscope for wafer inspection or metrology, which comprises: (a) filtering the initial UV light source and filtering the optical band, or filtering discrete bands according to the particular wafer inspection or metrology application Generating a spectrum; (3) illuminating the wafer with an optimized multi-band UV light source; (4) imaging the wafer, comprising: (a) collecting image reflections from the wafer surface via an optical band objective lens and scattering multiband UV light from the wafer surface, and (b) on an optically sensitive camera surface Focusing and scattering the image reflections via the optical band tube lens; (c) digitizing the distribution of light intensity, and (d) storing the digitized light intensity distribution; And (5) processing the image of the digitized light intensity distribution stored and digitized in accordance with the desired application, comprising: (a) applying a specific algorithm for processing the digitized wafer image; And (b) using and displaying the results for analysis of the wafer surface.

One preferred embodiment of a system of multi-band UV light illumination of a wafer for an optical microtechnology wafer inspection and metrology system of the present invention is characterized by the following main configuration. (1) an optical microscope, characterized by a wideband objective lens system, a wideband illumination path, and a wideband tube lens; (2) an initial ultraviolet light source that is part of an optical microtechnology wafer inspection or metrology system; (3) an apparatus for generating a multi-band ultraviolet light source from said initial ultraviolet light source, said device filtering out the optical band or discontinuous band of said initial ultraviolet light source; And (4) a wafer illuminated by using a multi-band ultraviolet light source. An additional configuration of one preferred embodiment of the system of the present invention is (5) an optically sensitive camera surface for receiving focused image reflections from the wafer surface via a lightband lens tube and for scattering multiband UV light. One camera; And (6) a data processing apparatus for digitizing the distribution of light source intensity characteristics of the surface of the wafer, storing the digitized light intensity distribution, and processing the stored and digitized light intensity distribution. The data processing apparatus used to process the stored and digitized distribution of the light intensity characteristics of the surface of the wafer is, but is not limited to, for wafer defect detection, wafer optical overlay metrology, and wafer optical critical size metrology. It features an algorithm.

According to the present invention, a method of multi-band ultraviolet ray illumination of an optical metrology wafer inspection and metrology system is provided, the method comprising the following steps. I.e. (a) providing an optical microscope characterized by a wideband objective system, a wideband illumination path, and a wideband tube lens; (b) placing the wafer on the sample holder of the optical microscope; (c) activating an initial ultraviolet light source, the initial ultraviolet light source being part of an optical microtechnology system; (d) generating a multi-band ultraviolet light source from the initial ultraviolet light source; (e) placing the wafer within the focal plane of the optical band objective system; (f) illuminating the wafer using a multi-band ultraviolet light source; (g) imaging the wafer using a multi band ultraviolet light source; (h) data processing an image of the wafer; And (i) displaying and using the results of the step of data processing the image of the wafer.

According to the present invention, there is provided a system of multi-band ultraviolet light illumination of a wafer for an optical microtechnology wafer inspection and metrology system, the system comprising; (a) optical microscopic technology featuring a wideband objective system, a wideband illumination path, and a wideband tube lens; (b) an initial ultraviolet light source that is part of an optical microtechnology system; (c) an apparatus for generating a multi-band ultraviolet light source from the initial ultraviolet light source; And (d) a wafer illuminated by using a multi-band ultraviolet light source.

In accordance with the present invention, a method is provided for generating a multi-band ultraviolet light source for optical microscopic inspection and metrology illumination of a wafer, the method comprising the following steps. That is, (a) providing an optical microscope characterized by an optical band objective lens system, optical band illumination path, and optical band tube lens; (b) activating an initial ultraviolet light source that is part of an optical microscope; (c) directing ultraviolet rays of the initial ultraviolet light source into the optical band ultraviolet illumination passageway; And (d) filtering the ultraviolet light rays of the initial ultraviolet light source by means selected from the group consisting of optical band filtering and discrete band filtering to produce a multi band ultraviolet light source of illumination, wherein the multi band ultraviolet light source of illumination is Characterizing the band ultraviolet light.

Implementation of the method of the present invention includes performing a manual, automatic or manual and automatic combination step or task. Moreover, depending on the actual machine and apparatus of a given wafer inspection system, several steps of the present invention may be performed by hardware or software or any combination thereof on any operating system of any firmware. For example, as hardware, the indicated steps of the present invention can be implemented as a chip or a circuit. As software, the indicated steps of the present invention can be implemented as a plurality of software instructions executed by a computer using any suitable operating system. In any case, the indicated steps of the method of the present invention may be performed by a data processor, such as a computing platform for executing a plurality of instructions.

1 is a flow chart illustrating a preferred embodiment of a wafer multi-band UV light illumination method for an optical microscope wafer inspection and metrology system in accordance with the present invention.

FIG. 2 illustrates an exemplary source image characterized by the actual arrangement of defects and patterns present in the surface image of the wafer under optical microscopy or measurement.

FIG. 3A shows a simulated image obtained by simulating the exemplary wafer of FIG. 2 for optical microscopy or metrology using a band white light illumination (400-600 nm) method. FIG.

FIG. 3B shows a simulated image obtained by simulating the exemplary wafer of FIG. 2 for optical microscopy or metrology using monochromatic UV light illumination (360-370 nm) method.

FIG. 3C shows a simulated image obtained by simulating the exemplary wafer of FIG. 2 for optical microscopy or metrology using multi-band UV light illumination (360-370 nm, 398-407 nm including visible bands 427-434 nm) method. One drawing.

4 corresponds to the cross section line of the image amplitude or pixel brightness (gray levels) versus the example wafer of FIG. 2 and the row 13 of the image grid shown in the simulated image of FIGS. 3A-3C. A graph showing the number of pixels to make.

FIG. 5 shows the image amplitude or pixel luminance (gray level) versus the number of pixels corresponding to the exemplary wafer of FIG. 2 and the cross-sectional line of the furnace 30 of the image grid shown in the simulated image of FIGS. 3A-3C. graph.

FIG. 6 shows the number of pixels corresponding to the image amplitude or pixel luminance (gray level) versus the example wafer of FIG. 2 and the cross-sectional line of column 21 of the image grid shown in the simulated image of FIGS. 3A-3C. graph.

FIG. 7 shows the number of pixels corresponding to the image amplitude or pixel luminance (gray level) versus the example wafer of FIG. 2 and the cross-sectional line of the furnace 53 of the image grid shown in the simulated image of FIGS. 3A-3C. graph.

Description of the main parts of the drawing

10: wafer

12,14,16,40a, 42a, 44a, 40b, 42b, 44b, 40c, 42c, 44c: Pattern

18,20,22,24,46a, 48a, 50a, 52a, 46b, 48b, 50b, 52b, 46c, 48c, 50c, 52c

26, 28, 54a, 56a, 54b, 56b, 54c, 56c: wafer surface

38a, 38b, 38c: simulation image

30,32,34,36,60,62,64,66,70,72,74,76,80,82,84,86: pixel grid lines

FIELD OF THE INVENTION The present invention relates to multiband UV light illumination methods and systems for wafers for optical microscope wafer inspection, and to metrology systems.

The multiband UV light illumination method and system of the wafer for optical microscope wafer inspection according to the present invention, and the steps and implementation of the metrology system will be described in more detail with reference to the accompanying specification and drawings. The invention shown in the drawings is presented for illustrative purposes only and is not intended to limit the invention in any way. For example, the description and the drawings of a preferred embodiment of the method of the present invention show two bands in the UV spectrum (ie 360-370 nm, 398-407 nm) and one band in the visible spectrum (ie 427-434 nm). , Refers to a wafer illumination light source exhibiting the characteristics of. Another embodiment of the method of the invention features at least three roughening light source bands in the UV spectrum, and at least two roughening light source bands in the visible spectrum.

Referring to the drawings, FIG. 1 is a flowchart illustrating a preferred embodiment of a multi-band UV light illumination method and metrology system for optical microscope wafer inspection in accordance with the present invention. In Fig. 1, the generally applicable main steps of the method of the invention are numbered and shown in the frame. An auxiliary step, which represents another characteristic of the main step of the method, is shown as an insertion phrase. The terms appearing in the following description are consistent with the terms used in FIG. 1.

In step 1, the optical microscope is initially set for wafer inspection. In step (a), an optical microscope having a wide band objective system and a wide band UV illumination path is provided. In step (b), a wide band objective system exhibiting a predetermined magnification range is selected with an optical microscope. In step (c), the wide band objective system is adjusted and set according to the wafer inspection application. In step (d), the wafer is placed on a sample holder (chuck). In step (e), a multi-band UV light source (ie, a mercury arc lamp which preferably characterizes the low pressure mercury vapor mixed with the rare gas) is operated. In step (f), the initial UV light source is transmitted through the wide band UV illumination path of the provided optical microscope.

In a second step, to optimize the optical microscope provided for wafer inspection. As wavelength filtering is required to generate certain spectral light sources, early multiband UV light sources generally exhibit UV light in the UV spectrum in addition to white light in the visible spectrum. In step (a), the multi-band UV light spectrum is generated according to the wafer inspection application by filtering the initial UV light source by wide band filtering or individual band filtering. Wide band UV light filtering is used instead of monochromatic UV light filtering. In a preferred embodiment according to the method of the invention, a multiband UV light source comprises two bands in the UV spectrum (ie 360-370 nm, 398-407 nm) and one band in the visible spectrum (wmr, 427-434 nm). It is characterized by. Another preferred embodiment of the method of the invention features at least three roughening light source bands in the UV spectrum, and at least two roughening light source bands in the visible spectrum. In step (b), the filtered multi wavelength UV light source is diluted. In step (c), the filtered multiband UV light source is aligned, centered, and oriented with respect to the wafer sample. In step (d), the wafer is positioned within the focal plane of the multi-band objective system.

In step 3, the wafer is illuminated by an optimally filtered multi-band UV light source. In step (a), the filtered multi-wavelength UV light source is transmitted through a wide band objective system. In step (b), the energy level UV mercury lamp is set according to the wafer inspection application. In step (c), the wafer surface is illuminated with a filtered multi band UV light source.

In step 4, an image of the wafer is shown. In step (a), scattering and collection of image reflections of multi-band UV light filtered from the wafer surface via a wide band objective lens system are shown. In step (b), image reflection and scattering is centered via a wide band tube lens on the optically sensitive camera surface. The camera surface receives a distribution of light intensities that reach the wafer surface. In step (c), the distribution of light intensities is digitized. In step (d), the dispersion of light intensity is stored in the memory of the image processor.

In step 5, image processing of stored digitized distributions of light intensity onto a wafer is provided according to a desired wafer inspection application. In step (a), a specified image processing algorithm is applied to process the digitized wafer image. Defect detection algorithms represent a category of specialized image processing algorithms commonly used in wafer inspection systems. Conventionally widely used defect detection algorithms are based on a comparison of wafer image data obtained from images of two adjacent regions of the same wafer. For example, an image of the first region of the pattern specified for a given wafer image may be used as the first reference image. An image of the second region characterizing the same specified pattern including the defect can be used as the second sample image. In this step, the defect is detected by direct subtraction of the first reference image from the second sample image. Execution of the form of a defect detection algorithm sets an image signal (pixel brightness or intensity measured at gray level) detection threshold to prevent false detection of the image signal due to diffraction effects, which is above the data points used in image processing. (Above the level of gray level for a given wafer area), the pixel luminance or intensity level measured at the gray level below the data point not used in image processing. Using the defect detection algorithm in the application of a preferred embodiment of the method of the present invention to an optical microscope wafer inspection system, the algorithm can be compared using the algorithm in an application of a method characterized by wide band light illumination or monochromatic UV light illumination of a wafer. At the same time, enabling the setting of a lower limit during processing of the obtained image data results in a significant measurable improvement in system resolution that equalizes the sensitivity of defect detection.

In step (b), the result of the processed wafer image is presented to the display device for analysis and characteristics of the wafer surface. Wide band UV light illumination methods of wafers for optical microscope wafer inspection and metrology systems are characterized by the characteristics of wafers exhibiting patterns and defects by metrology or optical microscopy using methods of wide band white light illumination monochromatic UV light illumination and multi-band UV light roughening. It is shown by computer simulation of the pattern. A more detailed description of the method according to the invention is digitized by comparing the figure showing the amplitude or pixel luminance (gray level) of the image shown in the drawing of an exemplary wafer versus the number of pixels in the partially displayed cross section of the pixel grid of the image. Analyze the wafer image.

FIG. 2 is a diagram 10 of the actual pattern arrangement and defects that appear in the surface image of the wafer due to optical microscopy or metrology. In Figure 2, the general pattern shown in the wafer image is shown as (12, 14, 16) and the defect is shown as (18, 20, 22, 24). Patterns 12, 14, and 16 have 200 nm, 50 nm, and 50 nm, respectively. The left and right sides of the pattern 12 are shown as 12a and 12b, respectively, and the center empty area is shown as 12c. Defects 18, 20, 22, 24 have critical dimensions of 100 nm, 50 nm, 200 nm, and 100 nm, respectively. Additional wafer surface areas at distances relatively away from patterns 12, 14, 16 and defects 18, 20, 22, 24 are indicated by reference 26, 28. 2 denotes the field of view (approximately 6.5 microns) of the optical microscope used in the method of the present invention and is represented by the frame periphery of the illustrative wafer. The grid lines corresponding to the furnace or column are shown in dashed lines (30:13, 32:32, 34:53, and 36:21 columns) and indicative of the indicated patterns, defects, and additional wafer surface areas. It is included in the drawings to provide in connection with the positioning of the image pixels. The same grid lines are included in the computer simulated image of the exemplary wafer shown in FIG. 2 to compare the results obtained using the method with the wide band white light illumination or monochromatic UV light illumination with the results using the invention.

3A, 3B, and 3C show wide band white light illumination (400-600 nm), monochromatic UV light illumination (360-370 nm), and multi band UV light illumination (visible bands 427-434 nm, 360--370 nm, 398-). 407 nm) is shown in the metrology or optical microscopy using the exemplary source image of FIG. 2, the simulated image obtained by simulating the wafer 10. The computer simulated image in this example is performed using a simulator algorithm of an optical microscope using an example source image, input of a drawing of the wafer 10. The simulator algorithm simulates the operation and performance of an ideal optical microscope and ignores the aberration effect. The simulator algorithm is based on an ideal lens model with a stationary filter in the back aperture. In the simulator algorithm, the back aperture is defined in the algorithm by two main variable values, the numerical aperture (for example NA of 0.9, the generator constant of the simulation image for each of the three illustrated and described wafer illumination methods), and Input the Applied Illumination Spectrum (i.e. wide band white light illumination of 400-600 nm; monochromatic UV light illumination of 360-370 nm; multi-band UV illumination of 360-370 nm and 398-407 nm including back bands 427-434 nm) It works. The operation of an ideal lens is mathematically described by Fourier transform between the image in the focal plane and the image in the back aperture. The image in the back aperture plane is the Fourier transform of the image in the focal plane. Mathematical equations describing the process are introduced in the reference 'Optical Principle: Electromagnetic Principles of Radio Waves, Interference and Diffraction of Radio Waves' in the 1998 edition of the Cambridge University Press, Born, Max, and Wolf, Emil. In the drawing of the input source image, the wafer 10 is converted into a light intensity distribution in the focal plane of the objective lens by a simulated optical microscope. Through simulation, the image is first transmitted through a first ideal lens and then through a back aperture stop filter, and a second ideal tube lens in which image magnification occurs. The output image is detected by the camera as in the light intensity distribution, and the camera senses the amplitude of the electromagnetic field.

In the simulation images shown in FIGS. 3A, 3B, and 3C, the field size of the field of view of each full output image obtained from the simulation is 6.5 microns. The pixel size of the simulated output image is 0.1 micron, or one pixel = 100 nm of the wafer 10 used in the simulation. Pixel amplitudes or intensities are indicated at the gray level in terms of luminance, and the power range is from 0 to 255 gray levels. The numerical aperture of the simulated optical microscope is constantly fixed to generate a simulated image for each of the three methods for wafer illumination (eg NA = 0.9). The difference in amplitude or pixel luminance appearing in the simulated image represents the actual difference obtained by using the directed method of the wafer roughness, and is not random or other artificial generated by using the simulator algorithm. Any information obtained near the edge of the field of view of the field of the wafer 10 corresponding to the region near the edge representing the simulated image is considered irrelevant to the method of the present invention and is shown in FIGS. 4, 5, 6, and 7 Shown in each, comparative graph quantitative analysis is provided in FIGS. 3A, 3B, and 3C.

FIG. 3A is a diagram of a simulated image 38a obtained by simulating according to the typical wafer 10 of FIG. 2 by optical microscopic inspection or metrology using the method of wide band white light illumination (400-600 nm). Patterns 12, 14 and 16, defects 18, 20, 22 and 24, additional wafer surface regions 26 and 28, and pixel grid lines 30 (column) of the typical wafer 10 of FIG. 2. 13), 32 (column 30), 34 (column 53), and 36 (lower 21)] are patterns 40a, 42a, and 44a, defects 46a, 48a, 50a, and 52a, and additional wafer surfaces. Areas 54a and 56a and pixel grid lines 60 (column 13), 62 (column 30), 64 (column 53), and 66 (lower 21) are correspondingly shown in FIG. 3A.

Important parts of FIG. 3A are as follows. The image resolution (ie, not the system resolution) of the patterns 40a, 42a, and 44a and the defects 46a, 48a, 50a, and 52a is the corresponding pattern 12 of the backed source image 10 of FIG. 2. 14 and 16) and corresponding defects 18, 20, 22 and 24, in comparison. The side and center blank areas of the pattern 40a are not necessarily resolved from each other. However, the uniformity of the pixel luminance gray level at pixel locations, for example, additional wafer surface regions 54a and 56a, spaced apart from the edges of the defects and patterns of the simulated image 38a; The value represents the minimum diffraction effect generated by the interaction between the lightband white light illumination source and pattern 40a, 42a, and 44a or defects 46a, 48a, 50a, and 52a. The minimum diffraction effect is converted to high system resolution for inspection and measurement of the surface of a typical wafer 10 (FIG. 2) by optical microscopy techniques using the method of optical band white light illumination.

FIG. 3B is a diagram of a simulated image 38b obtained by simulating along the typical wafer 10 of FIG. 2 by optical microtechnical inspection or metrology using the method of monochromatic UV light illumination (360-370 nm). Patterns 12, 14 and 16, defects 18, 20, 22 and 24, additional wafer surface areas 26 and 28, and pixel grid lines 30 (column 13) of the typical wafer 10 of FIG. 2. , 32 (column 30), 34 (column 53), and 36 (lower 21) are patterns 40b, 42b, and 44b, defects 46b, 48b, 50b, and 52b, and additional wafer surface area 54b. And 56b) and the pixel grid lines 70 (column 13), 72 (column 30), 74 (column 53), and 76 (lower 21) correspondingly to FIG. 3B.

Important parts of FIG. 3B are as follows. The image resolution (ie, not the system resolution) of the patterns 40b, 42b, and 44b and the defects 46b, 48b, 50b, and 52b is determined by the corresponding patterns 12, 14 and of the typical wafer 10 of FIG. 16) and the image resolution of the corresponding patterns 40a, 42a, and 44a, and the defects 46a, 48a, 50a, and 52a, and the simulated image 38a, for the corresponding defects 18, 20, 22, and 24. Compared better. The side and center blank areas of the pattern 40 are not resolved from each other. Furthermore, the image resolution of the cross pattern 42b and the two bottom and one top left extensions of the pattern 44b in addition to the center portion for the method of using the optical band white light illumination of the typical wafer 10 (FIG. 2). The part compares considerably higher with the image resolution of the corresponding pattern part shown in the simulation image 38a.

However, in contrast to the simulated image 38a, pixel locations spaced apart (eg,> 200 nm) from the edge of the pattern or defect of the simulated image 38b, for example additional wafer surface regions 54b and 56b. The notable change in pixel luminance gray level at represents a significant diffraction effect caused by the interaction between monochromatic UV light illumination sources and patterns 40b, 42b, and 44b or defects 46b, 48b, 50b, and 52b. . Compared to the minimal diffraction effect seen in the simulated image 38a, the significant diffraction effect in the simulated image 38b is typically achieved by optical microscopy techniques using the method of monochromatic UV light illumination as compared to the method of optical band white light illumination. 10) (converted to a significantly lower system resolution for inspection and metrology of the surface of FIG. 2).

3C is a simulation obtained by simulating according to the typical wafer 10 of FIG. 2 by optical microscopic techniques or metrology using a method of multi-band UV light illumination (360-370 nm, 398-407 nm, 427-434 nm). Is a view of an image 38c. Patterns 12, 14, and 16 of the typical wafer 10 of FIG. 2, defects 18, 20, 22, and 24, additional wafer surface areas 26 and 28, and pixel grid lines 30 (column 13). ), 32 (column 30), 34 (column 53), and 36 (lower 21)] are patterns 40c, 42c, and 44c, defects 46c, 48c, 50c, and 52c, and additional wafer surface area 54c. And 56c) and the pixel grid lines 80 (column 13), 82 (column 30), 84 (column 53), and 86 (lower 21) corresponding to FIG. 3C.

Important parts of FIG. 3C are as follows. The image resolution (ie, not the system resolution) of the patterns 40c, 42c, and 44c and the defects 46c, 48c, 50c, and 52c is determined by the corresponding patterns 12, 14 and of the typical wafer 10 of FIG. 16) and image resolution of corresponding patterns 40a, 42a, and 44a, and defects 46a, 48a, 50a, and 52a, and simulated image 38a for corresponding defects 18, 20, 22, and 24; Compared to considerably better. The side and center blank areas of the pattern 40c are not necessarily resolved from each other. Moreover, the image resolution of the cross pattern 42c, and in addition to the center of the pattern 44c, the two bottom and one upper left extensions utilize the method of using the optical band white light illumination of a typical wafer 10 (FIG. 2). For this reason it is considerably higher than the image resolution of the corresponding pattern part shown in the simulation image 38a.

The pattern of the simulated image 38c, characterized by the multi-band UV illumination of a typical wafer 10, and the image resolution of the defect (i.e., not the system resolution) and the monochromatic UV light illumination of the typical wafer 10 For comparison of the pattern of the simulated image 38b and the image resolution of the defects, the image resolution obtained using a method characterized by multiband UV light illumination of a typical wafer 10 is obtained from the monochromatic UV light of a typical wafer 10. It is comparable to the image resolution obtained using a method characterized by illumination.

The presence of diffraction effects in the simulated image 38c obtained by carrying out the method characterized by the multi-band UV light illumination according to the invention, although shown in the simulated image 38a for the method characterized by the optical band white light illumination Changes in pixel luminance gray levels at pixel positions that are not as small as pixel luminance gray levels but spaced apart (eg,> 200 nm) from the edges of the pattern or defect, for example, additional wafer surface regions 54c and 56c. Is significantly less than the variation shown in the simulated image 38b for the method characterized by the monochromatic UV light illumination of a typical wafer 10. The method using multi-band UV light illumination enables efficient variation of defects and typical wafer patterns with Gaussian envelopes, thereby reducing the interfering diffraction effect compared to the method using monochromatic UV light illumination. By varying the degree of diffraction effect into the system resolution for optical microtechnology wafer inspection or metrology systems, higher system resolutions are achieved by methods that feature multi-band UV light illumination as compared to methods characterized by monochromatic UV light illumination. It is possible. This indicates that there is a higher likelihood and precision of detection and resolution and measurement of wafer defects and patterns compared to using monochromatic UV light illumination in using a method that features multi-band UV light illumination of the wafer.

4-7 are plots of image size and pixel brightness (gray level) versus number of pixels, each plot being in the diagram of the typical wafer 10 of FIG. 2, and each of FIGS. 3A, 3B, and 3C Columns of the image grid shown in the simulation images 38a, 38b, and 38c correspond to different transverse lines of the furnace. Data and information included in FIGS. 4-7 are image resolution, diffraction effects and systems as seen by FIGS. 3A, 3B, and 3C of different methods of illuminating wafers for application to optical microtechnology wafer inspection and metrology systems. The results and conclusions related to the comparison of resolution are further measured.

4 is a plot of the image size or pixel luminance (gray level) versus the number of pixels corresponding to the cross-section of column 13 of the image grid shown in the diagram of the typical wafer of FIG. 2 and the simulated image of FIGS. 3A-3C. Drawing. In Fig. 4, curves 90, 92, and 94 show pixel grids (wafers) corresponding to the application of the method characterized in that they use optical band white light wafer illumination, monochromatic UV ray wafer illumination, and multi-band UV ray wafer illumination, respectively. Gray level versus pixel, viewed from left to right along the transversal line of column 13 of 30 by 30 in figure 10, by 60, 70 and 80 in simulated images 38a, 38b and 38c, respectively. The image size or number of pixels in units of number is a float of luminance. For all curves 90, 92, and 94, the steepness in pixel luminance at pixel counts less than 5 represents the diffraction effect occurring at the edge of the field in terms of the typical wafer 10 of FIG. It does not relate to discussion of differences in image resolution, diffraction effects, or system resolution among different methods.

The main part of FIG. 4 is as follows. Excellent image of pattern 12 and pattern side surfaces 12a and 12b and pattern center portion 12c of FIG. 2 corresponding to patterns 40b and 40c of simulation images 38b and 38c of FIGS. 3b and 3c, respectively. The resolution is evident by the maximum (96a and 96b) and the minimum (96c) in the number of pixels between 25 and 30, respectively, along curves 92 and 94 for each method of monochromatic UV light illumination and multi-band UV light illumination. Is displayed. The inferior image resolution of the pattern 12 and the pattern side surfaces 12a and 12b and the pattern center portion 12c of FIG. 2 corresponding to the pattern 40a of the simulated image 38a of FIG. 3a for the method of optical band white light illumination It is clearly indicated by 96d at the number of pixels between 27 and 30 along the curve 90. Moreover, image resolution, curve 94, obtained by simulating a method characterized by the use of multi-band UV light illumination, curve 94 is an image resolution, curve 92 obtained by simulating a method characterized by the use of monochromatic UV light illumination. Is almost the same as

For comparison of the diffraction effect due to the interaction between the illumination light source present on the typical wafer 10 of FIG. 2 and the interaction between the pattern or the defect edges, the methods of monochromatic UV light illumination and multi-band UV light illumination were obtained using each method. Regions 98 and 100 of FIG. 4 are left along FIG. 3B (i.e., column 13 70 of pattern 40b, edge regions of defects 46b, 48b, 50b, and 52b), and wafer surface region 54b. To the right], and FIG. 3C (ie, column 13 80 of pattern 40c, edge regions of defects 46c, 48c, 50c, and 52c), and wafer surface region 54c. Curves 92 and 94 corresponding to the simulated image 38c of the left side to the right side of the image] are shown in FIG. 3A (i.e., column 13 60 of the pattern 40a), which are obtained by using a method of wide band white light illumination. Edge area of 46a, 48a, 50a, and 52a, and from left to right along wafer surface area 54a] Compared to curve 90, corresponding to the illustration image (38a) it represents a significant change in the pixel brightness. However, the change in pixel brightness shown by curve 94 corresponding to multi-band UV light illumination (FIG. 3C) is the change in pixel brightness shown by curve 92 corresponding to monochromatic UV light illumination (FIG. 3B). Less than This result is consistent with the discussion of FIG. 3C, whereby higher system resolution is achievable for methods featuring multi-band UV light illumination as compared to methods featuring monochromatic UV light illumination.

5 is an image size or pixel luminance (gray level) vs. pixel corresponding to a cross-section of column 30 of the image grid shown in the diagram of a typical wafer 10 in the simulation image of FIGS. 2 and 3A-3C. Figure of number. In FIG. 5, curves 110, 112, and 114 show a pixel grid (corresponding to the application of the method characterized by the use of wide band white light wafer illumination, monochromatic UV ray wafer illumination, and multi-band UV ray wafer illumination). Viewed from left to right along the transversal line of column 30 of 32 (indicated by 62, 72, and 82 of each of simulated images 38a, 38b, and 38c), by 32 in wafer drawing 10, It is a plot of image size or pixel brightness in units of gray level versus number of pixels. For all curves 110, 112, and 114, the steepness of the pixel brightness at less than 5 pixel numbers exhibits the diffraction effect appearing at the edge of the field of the typical wafer 10 of FIG. 2, with different methods of ray illumination of the wafer. Among others are not relevant to the discussion of differences in image resolution, diffraction effects, or system resolution.

The main part of FIG. 5 is as follows. The very high image resolution of the pattern 14 of FIG. 2 corresponding to the patterns 42b and 42c of the simulated images 38b and 38c of FIGS. 3b and 3c along the curve 110 for the method of optical band white light illumination. Each method of monochromatic UV light illumination, and multi-band UV light illumination as compared to the image resolution of pattern 14 of FIG. 2 corresponding to pattern 42a of simulated image 38a of FIG. 3A for the same range of pixel counts. Is indicated by the minimum regions 116 and 118 for the number of pixels between 12 and 13 along the curves 112 and 114, respectively. Moreover, image resolution, curve 114, obtained by simulating a method characterized by the use of multi-band UV light illumination image curve, 112, obtained by simulating a method characterized by the use of monochromatic UV light illumination. Is essentially the same as

For comparison of the diffraction effect by the interaction between the illumination light source present on the typical wafer 10 of FIG. 2 and the pattern or defect edges, the regions 120 and 122 of FIG. 5 are monochromatic UV light illumination and multiple bands. 3b (i.e., left to right along the edge regions of columns 30 72, defects 50b and 52b and patterns 40b, 42b and 44b of FIG. 40a respectively obtained by using the method of UV ray illumination) When viewed from left to right along the edge region of the simulation image 38b, and FIG. 3C (ie, column 30 82, defects 50c and 52c, and patterns 40c, 42c and 44c); Curves 112 and 114 corresponding to the simulated image 38c of FIG. 3A (ie, column 30 62, defects 50a and 52a) and patterns 40a, 42a, obtained by using the method of wide band white light illumination And from the left to the right along the edge area of 44a) to the curve 110 corresponding to the simulated image 38a. Thus only a suitable change in pixel brightness is presented.

FIG. 6 is an image size or pixel luminance (gray level) versus pixel number corresponding to the transverse line of the furnace 21 of the image grid shown in the diagram of the typical wafer 10 of FIG. 2 and the simulated image of FIGS. 3A-3C. Is a plot of. Curves 130, 132, and 134 of FIG. 6 show pixel grids (simulated images 38a) corresponding to the application of the method characterized by optical band white light wafer illumination, monochromatic UV ray wafer illumination, and multi-band UV ray wafer illumination, respectively. Gray level vs. number of pixels when viewed from top to bottom along a transverse line of the furnace 21 of [indicated by 36 in the wafer drawing 10 by 66, 76, and 86 in FIGS. Is the float of the image size or pixel brightness. The steep slope of pixel brightness at less than four pixel counts for curves 130, 132 and 134 exhibits the diffraction effect occurring at the edge of the field of the typical wafer 10 of FIG. 2, among the different methods of ray illumination of the wafer. It does not relate to the discussion of differences in image resolution, diffraction effects, or system resolution.

The main part of FIG. 6 is as follows. The very high image resolution of the pattern 14 of FIG. 2 corresponding to the patterns 42b and 42c of the simulated images 38b and 38c of FIGS. 3b and 3c results in a curve 130 for the method of optical band white light illumination. Along the curves 132 and 134 for the respective methods of monochromatic UV light illumination, and multi-band UV light illumination, corresponding to the pattern 42a of the simulated image 38a of FIG. 3A for the same range of number of pixels. It is indicated by the minimum area 136 in the number of pixels between and 35. Moreover, the image resolution obtained by simulating the method characterized by the use of multi-band UV ray illumination is very similar to the image resolution obtained by simulating the method characterized by the use of monochromatic UV ray illumination, minimum region 136. . Therefore, once again, the image resolution of the pattern on the typical wafer 10 of FIG. 2 is improved by applying the method of multiband UV light illumination of the present invention as compared to applying the method of lightband white light illumination.

For comparison of diffraction effects by interaction between illumination light sources and pattern or defect edges present in the typical wafer 10 of FIG. 2, regions 140 and 142 of FIG. 6 are monochromatic UV light illumination and multi-band UV light. FIG. 3B (i.e., furnace 21, 76, defects 46b, 48b, 50b, and 52b) and edge regions of patterns 40b, 42b, and 44b obtained by using the method of ray illumination, and wafer surface region 56b Of the simulated image 38b, as seen from top to bottom, and FIG. 3C (ie, furnace 21 86, defects 46c, 48c, 50c and 52c), and patterns 40c, 42c, and 44c. The curves 132 and 134 corresponding to the edge region, and the simulated image 38c of the top and bottom view along the wafer surface area 56c] are obtained by using the method of wide band white light illumination (i.e., Along the edges 21 of the furnace 21, the defects 46a, 48a, 50a and 52a, and the patterns 40a, 42a and 44a, and the wafer surface area 56a. It represents a significant change in the pixel brightness compared to curve 130 which corresponds to the simulated image (38a) as seen from top to bottom. However, the change in pixel brightness shown by the curve 134 corresponding to the multi-wavelength UV light illumination (FIG. 3C) is significantly greater than the change in pixel brightness shown by the curve 132 corresponding to the monochromatic UV light illumination (FIG. 3B). little. This result is consistent with the discussion of FIG. 3C, where a higher system resolution is achievable for methods featuring multiband UV light illumination as compared to methods characterized by monochrome UV light illumination.

FIG. 7 shows the image size or pixel luminance (gray level) versus the number of pixels corresponding to the transverse line of the column 53 of the image grid shown in the diagram of the typical wafer 10 of FIG. 2 and the simulated image of FIGS. 3A-3C. It is a drawing of a float. In FIG. 7, curves 150, 152, and 154 show pixel grids corresponding to the application of the method characterized by the use of wide band white light wafer illumination, monochromatic UV ray wafer illumination, and multi-band UV ray wafer illumination. Gray level vs. pixel count when viewed from left to right along the transversal line of column 34 of FIG. 10 and column 53 of the simulation images 38a, 38b, and 38c, represented by 64, 74, and 84, respectively. A float of the image size or pixel luminance in units. For all curves 150, 152 and 154, the steepness of the pixel luminance at the number of pixels less than 5 represents the diffraction effect occurring on the edge of the field of the typical wafer 10 of FIG. 2, and different methods of ray illumination of the wafer. It does not relate to the discussion of differences in image resolution, diffraction effects, or system resolution.

The main part of FIG. 7 is as follows. There are no patterns or defects along the diagram 53 of the typical wafer 10 of FIG. 2 and the column 53 of the pixel grid of the simulated images 38a, 38b, and 38c (FIGS. 3a, 3b, and 3c). Therefore, in Fig. 7, there is no comparison related to the image resolution of the pattern or the defect. For comparison of diffraction effects due to the interaction between the illuminating light source and the pattern or defect edges present on the typical wafer 10 of FIG. 2, obtained by using the methods of monochromatic UV light illumination and multi-band UV light illumination. , A simulation image of FIG. 3B (ie, viewed from left to right along the column 53 74, the bottom edge of the pattern 44b, and the wafer surface area 56b) in the range of pixel numbers 7 to 65; Curves 152 and 154 of FIG. 7 corresponding to 38b) are shown in FIG. 3A (i.e., column 53 64, bottom edge of pattern 44a, and wafer surface area 56a obtained by using a method of wide band white light illumination). ), Corresponding to the simulation image 38a of the view from left to right, shows a significant change in pixel luminance compared to the curve 150. However, the change in pixel brightness shown by the curve 154 corresponding to the multi-wavelength UV light illumination (FIG. 3C) is significantly greater than the change in pixel brightness shown by the curve 152 corresponding to the monochromatic UV light illumination (FIG. 3B). small. As indicated in the discussion of FIGS. 4 and 6, higher system resolution is achievable for methods featuring multi-band UV light illumination as compared to methods featuring monochrome UV light illumination.

The main configuration of one preferred embodiment of a system of multiband UV light illumination of a wafer for an optical microtechnology wafer inspection and metrology system of the present invention is as follows. That is, the main configuration includes (1) an optical microscope characterized by a lightband objective system, a lightband illumination path, and a lightband tube lens; (2) an initial ultraviolet light source that is part of an optical microtechnology wafer inspection or metrology system; (3) an apparatus for generating a multi-band ultraviolet light source from the initial ultraviolet light source, the apparatus performing optical band filtering or discontinuous band filtering of the initial ultraviolet light source; And (4) a wafer illuminated by using a multi-band ultraviolet light source. An additional configuration of the preferred embodiment of the system of the present invention is (5) an optically sensitive camera surface for receiving focused image reflections from the wafer surface via a lightband tube lens and for scattering multiband UV light. Camera and (6) a data processing device for digitizing the distribution of lens intensity characteristics of the wafer surface, storing the digitized light intensity distribution, and processing the stored and digitized light intensity distribution. The data processing apparatus used to process the stored and digitized characteristic distribution of the light intensity of the surface of the wafer is a special algorithm for, but not limited to, wafer defect detection, wafer optical overlay metrology, and wafer optical critical size metrology. It is characterized by.

While the present invention has been described in connection with specific embodiments, many choices, modifications, and variations are apparent to those skilled in the art. Accordingly, all such choices, modifications, and variations are attached.

As such, the invention significantly improves the measurable resolution of a single object or structure as compared to methods featuring optical band white light illumination, and compared to methods featuring monochromatic UV light illumination without generating radiation damage to the wafer. The overall system resolution of the wafer image is significant and measurable.

Claims (26)

As a multi-band ultraviolet ray illumination method of wafers for optical inspection and wafer inspection and measurement systems, (a) providing an optical microscope having an optical band objective lens system, optical band illumination path, and optical band tube lens; (b) placing the wafer on a sample holder of the optical microscope; (c) activating an initial ultraviolet light source that is part of the optical microtechnical system; (d) generating a multi-band ultraviolet light source from said initial ultraviolet light source; (e) placing the wafer within the focal plane of the optical band objective lens system; (f) illuminating the wafer using the multi-band ultraviolet light source; (g) imaging a wafer using the multi band ultraviolet light source; (h) data processing the image of the wafer; And (i) a method for multiband ultraviolet ray illumination of a wafer for wafer inspection and metrology systems of optical microscopic technology, comprising displaying and using data processed image results of the wafer; The method of claim 1, wherein providing an optical microscope characterized by an optical band objective lens system comprises: (Iii) selecting the optical band objective system having a plurality of magnifying glasses applicable to the optical microtechnology system; And (Ii) adjusting and setting the optical band objective lens system in accordance with the application of the optical microtechnology system. 2. The method of claim 1, further comprising sending ultraviolet light rays of the initial ultraviolet light source into the optical band ultraviolet illumination passageway. The method of claim 1, wherein the light band of the multi band ultraviolet light ray is considered monochromatic. 2. The method of claim 1, wherein generating a multiband ultraviolet light source from the initial ultraviolet light source comprises filtering the ultraviolet light of the initial ultraviolet light source by means selected from the group consisting of optical band filtering and discrete band filtering. How to. The method of claim 1, wherein the multiband ultraviolet light source from the initial ultraviolet light source comprises a band of the visible light spectrum in addition to the multiple bands of the ultraviolet light spectrum. 2. The method of claim 1, further comprising the steps of: (j) reducing the multi band ultraviolet light rays of the multi band ultraviolet light source; And (k) aligning, focusing, and rotating the multi-band ultraviolet light rays of the multi-band ultraviolet light source according to the application of the optical microtechnical system. The method of claim 1, wherein illuminating the wafer using the multi-band ultraviolet light source comprises: (i) sending multi-band ultraviolet light rays of the multi-band ultraviolet light source through the optical band objective lens system; And (ii) setting an energy level of the initial ultraviolet light source in accordance with the application of the optical microtechnical system. The method of claim 1, wherein imaging the wafer using the multi-band ultraviolet light spectrum comprises: (Iii) collecting image reflections and scattering multiband ultraviolet light rays of the multiband ultraviolet light source coming from the surface of the wafer using the optical band objective lens system; (Ii) focusing the image reflection and scattering the multi-band ultraviolet light beam of the multi-band ultraviolet light source using the optical band tube lens onto the optically sensitive camera surface, wherein the optically sensitive camera surface is Accepting a distribution of light intensity characteristics of the surface of the wafer; (Iii) digitizing the distribution of light intensity characteristics of the surface of the wafer to form the digitized light intensity distribution; And (Iii) storing and using the digitized distribution of light intensity. The method of claim 1, wherein data processing the image of the wafer further comprises applying a special algorithm to process the characteristic distribution of the digitized light intensity of the surface of the wafer. 11. The method of claim 10, wherein the special algorithm is selected from the group consisting of a defect detection algorithm, a wafer optical overlay metrology algorithm, and a wafer engineering crystal size metrology algorithm to process the characteristic distribution of digitized light intensity on the surface of the wafer. Way. Multi-band ultraviolet light illumination system for wafers for optical inspection and wafer inspection and measurement systems (a) an optical microscope characterized by a wideband objective system, a wideband illumination path, and a wideband tube lens; (b) an initial ultraviolet light source that is part of the optical microtechnical system; (c) a device for generating a multi-band ultraviolet light source from said initial ultraviolet light source; And And a wafer illuminated by using said multi-band ultraviolet light source. A multi-band ultraviolet ray illumination system of a wafer for an optical microscopic wafer inspection and metrology system. 13. The system of claim 12, wherein the light band of the multi band ultraviolet light rays is considered monochromatic. 13. The system of claim 12, wherein the optical band objective lens system comprises a plurality of magnifying glasses applicable to optical microscopic systems. 13. The system of claim 12, wherein the apparatus for generating the multi-band ultraviolet light source from the initial ultraviolet light source is selected from the group consisting of an optical band filter and a discrete band filter. 13. The system of claim 12, wherein the optical band objective lens is characterized by a focal plane in which the wafer is disposed. 13. The optical band objective lens system of claim 12, wherein the optical band objective system is used to pass a multi band ultraviolet ray of the multi band ultraviolet light source on a surface of the wafer, wherein the optical band objective lens conjures image reflection and And scatter the multi-band ultraviolet light rays of the multi-band ultraviolet light source from the surface of the system. 13. The optical band tube lens of claim 12, wherein the optical band tube lens concentrates image reflections from the surface of the wafer onto an optically sensitive camera surface and scatters multiple band ultraviolet light rays of the multiband ultraviolet light source. A system for receiving a distribution of light intensity characteristics of said surface of said wafer. The method of claim 12, (e) a data processing apparatus for digitizing the distribution of light intensity characteristics of the surface of the wafer, storing the digitized light intensity distribution and processing the stored digitized light intensity distribution. 20. The apparatus of claim 19, wherein the data processing apparatus for processing the stored and digitized characteristic distribution of the light intensity of the surface of the wafer comprises a wafer defect detection algorithm, a wafer optical overlay metrology algorithm, and a wafer optical critical size metrology algorithm. A system characterized by a particular algorithm selected from the group consisting of. A method of generating a multiband ultraviolet light source of illumination for inspection and measurement of optical microscopic technology of a wafer, (a) providing an optical microscope characterized by a wideband objective system, a wideband illumination path, and a wideband tube lens; (b) activating an initial ultraviolet light source that is part of the optical microscope; (c) directing ultraviolet light rays of said initial ultraviolet light source into said optical band ultraviolet light path; (d) filtering said ultraviolet light rays of said initial ultraviolet light source by means selected from the group consisting of optical band filtering and discrete band filtering to generate said multi-band ultraviolet light source of illumination, wherein said multi-band ultraviolet light of illumination is provided. The light source comprises characterizing multi-band ultraviolet light, wherein the multi-band ultraviolet light source of illumination for inspection and metrology of optical microscopic techniques of the wafer. The method of claim 21, wherein the light band of the multi band ultraviolet light ray is considered monochromatic. 22. The method of claim 21, further comprising: (e) reducing the multi-band ultraviolet light rays of the multi-band ultraviolet light source of illumination; And (f) aligning, concentrating, and rotating the multi-band ultraviolet light rays of the multi-band ultraviolet light source of illumination in accordance with the application of inspection and metrology of optical microscopic techniques of wafers. 22. The method of claim 21, further comprising: (e) sending a multiband ultraviolet light beam of the multiband ultraviolet light source through the optical band objective lens system; And (f) setting an energy level of the initial ultraviolet light source in accordance with the application of inspection and metrology of optical microscopic techniques of the wafer. 22. The method of claim 21, wherein the multi-band ultraviolet light source generated from the initial ultraviolet light source comprises bands in the visible light spectrum of the multiple bands of the ultraviolet light source spectrum. 22. The method of claim 21, wherein the optical band objective lens system comprises a plurality of magnifying glasses applicable to optical microscopic inspection and metrology of a wafer.