JP2004333227A - Semiconductor wafer inspection apparatus, image detection method, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor wafer inspection apparatus and an image detection method for detecting and recognizing a desired pattern on a wafer without any marks, and to provide a semiconductor device formed through the utilization. <P>SOLUTION: A wide-band light source 12 irradiates a semiconductor wafer 10 via an optical system 13 with wide-band light Lin. A filter mechanism 14 includes color filters 141-143, and divides reflection light Lre in a region to be inspected into each wavelength band of three primary colors (R, G, B). A signal processing section 15 digitizes a signal at each separated wavelength band. A comparison and computation mechanism 16 includes a buffer memory, accumulates data at each wavelength band obtained by the signal processing section 15, successively compares data in the same positional relationship, and detects only the matched identical data as the data of an acquisition image pattern. An output section 17 graphically displays a pattern according to the data of the acquisition image pattern on a monitor finally. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to semiconductor device manufacturing, and more particularly to a semiconductor wafer inspection apparatus and an inspection method for recognizing a pattern on a semiconductor wafer or detecting a pattern defect, and a semiconductor device formed through the use thereof.
[0002]
[Prior art]
A pattern required for LSI manufacturing is reduced-projection-exposed on a semiconductor wafer (hereinafter, also referred to as a wafer) using a photomask such as a reticle. That is, the pattern is repeatedly projected and exposed on the semiconductor wafer while sequentially moving the region to be projected. Various processing steps such as a film forming step, an etching step, and a cleaning step are performed between the exposure steps. As a result, it is necessary to secure as many chip products as possible for a given application from one wafer. In addition, the mass production must be performed with uniform performance and high yield.
[0003]
The number of defects in the wafer increases or decreases due to the search for optimization conditions and process control in the LSI manufacturing process. Inspection of a pattern defect due to a defect in an exposure pattern or adhesion of a foreign substance on a wafer due to generation of a particle, and inspection of a defect due to the defect are generally achieved by a comparative inspection. That is, a defect inspection apparatus (or a wafer inspection apparatus) captures image data of the same pattern area of an adjacent integrated circuit chip area and performs a comparative inspection through signal processing. A portion determined as a defect is specified based on the inspection result.
[0004]
In some cases, a portion determined as a defect on a semiconductor wafer is actually confirmed based on the defect data based on the inspection result. For this reason, light of a predetermined wavelength is made incident so as to include a portion determined as a defect on the semiconductor wafer, and the reflected light is captured by a CCD or the like. A gradation is performed according to the contrast of the captured data, and a pattern including a portion determined to be defective is formed into a graphic.
[0005]
[Problems to be solved by the invention]
However, the reflected light from the semiconductor wafer depends on the film thickness and film quality of the irradiated portion, and affects the color. When a pattern is formed at the center of the contrast, this difference in color becomes noise when the pattern is recognized. As a result, a pattern different from the actual pattern may be formed.
[0006]
The present invention has been made in view of the above-described circumstances, and is formed through a semiconductor wafer inspection apparatus and an image detection method capable of detecting or recognizing a desired pattern on a wafer without noise, and a method of using the same. It is an object of the present invention to provide a semiconductor device.
[0007]
[Means for Solving the Problems]
A semiconductor wafer inspection apparatus according to the present invention includes an illumination optical system that irradiates an inspection area on a semiconductor wafer with broadband light to obtain reflected light, and outputs reflected light of the inspection fixed area into three or more types of wavelength bands. Filter mechanism, a signal processing unit for digitizing the signal of each wavelength band, and a comparison operation for comparing data of each wavelength band obtained by the signal processing unit and detecting the same data as data of an acquired image pattern. A mechanism and an output unit for at least the acquired image pattern are provided.
[0008]
According to the semiconductor wafer inspection apparatus of the present invention, the reflected light is divided into various color components by the filter mechanism, and each is digitized by the signal processing unit. The comparison operation mechanism compares these data and detects only the same data as the data of the acquired image pattern. As a result, noise caused by the color difference can be removed.
[0009]
The semiconductor wafer inspection apparatus according to the present invention has the following features as preferred embodiments.
The inspection area is set based on externally provided coordinate data. This is useful for actual pattern inspection according to the data for which defect inspection has been performed.
The inspection area is a scanning area for a plurality of chips on the semiconductor wafer.
More preferably, a stage that supports the semiconductor wafer and controls movement so that the inspection region is scanned, and sequentially stores data of an acquired image pattern detected by the comparison operation mechanism in accordance with the scanning of the inspection region. A memory unit, and an arithmetic and control unit for comparing data of the acquired image patterns for the same chip region on the semiconductor wafer and detecting different defect data, and outputting the acquired image pattern including the defect data to the output unit. It is characterized in that it is transmitted to a part.
In other words, the comparison between adjacent chip areas or further identical chip areas is performed using data from which noise has been eliminated, and the accuracy and reliability are improved.
Further, each of the three or more wavelength bands is a wavelength band of three primary colors (R, G, B). It is easiest to separate the wavelength bands.
[0010]
A semiconductor wafer inspection apparatus according to the present invention includes: an illumination optical system that irradiates an inspection area on a semiconductor wafer with three or more types of different short-wavelength lights to obtain respective reflected lights; and a reflection of each of the short-wavelength lights in the inspection area. A signal processing unit that converts the light into data, a comparison operation mechanism that compares data of each short-wavelength light obtained by the signal processing unit, and detects the same data as data of an obtained image pattern, and at least regarding the obtained image pattern And an output unit.
[0011]
According to the semiconductor wafer inspection apparatus of the present invention, three or more types of different short-wavelength lights are used as inspection light, and each is digitized by a signal processing unit. The comparison operation mechanism compares these data and detects only the same data as the data of the acquired image pattern. As a result, noise caused by the color difference can be removed.
[0012]
The semiconductor wafer inspection apparatus according to the present invention has the following features as preferred embodiments.
The inspection area is set based on externally provided coordinate data. This is useful for actual pattern inspection according to the data for which defect inspection has been performed.
The inspection area is a scanning area for a plurality of chips on the semiconductor wafer.
More preferably, a stage that supports the semiconductor wafer and controls movement so that the inspection region is scanned, and sequentially stores data of an acquired image pattern detected by the comparison operation mechanism in accordance with the scanning of the inspection region. A memory unit, and an arithmetic and control unit for comparing data of the acquired image patterns for the same chip region on the semiconductor wafer and detecting different defect data, and outputting the acquired image pattern including the defect data to the output unit. It is characterized in that it is transmitted to a part.
That is, noise is eliminated in comparison with adjacent chip regions, and the accuracy and reliability are improved.
[0013]
An image detection method according to the present invention includes a step of irradiating an inspection area on a semiconductor wafer with broadband light, a step of dividing reflected light of the inspection fixed area into three or more types of each wavelength band, and And a step of comparing data of the respective wavelength bands to detect the same data as data of an acquired image pattern, and at least an output step of the acquired image pattern.
[0014]
According to the image detection method of the present invention, the inspection area is irradiated with broadband light, the reflected light is divided into three or more types of wavelength bands, and each is converted into data. These data are compared, and only the same data is detected as the data of the acquired image pattern. As a result, noise caused by the color difference can be removed.
[0015]
An image detection method according to the present invention includes a step of irradiating an inspection area on a semiconductor wafer with three or more types of different short-wavelength lights at predetermined timings, and converting reflected light of each of the short-wavelength lights in the inspection area into data. And comparing the data of the respective wavelength bands and detecting the same data as data of the acquired image pattern, and at least an output step relating to the acquired image pattern.
[0016]
According to the above-described image detection method according to the present invention, three or more types of different short-wavelength lights are radiated to the inspection area at predetermined timings, and the reflected lights are converted into data. These data are compared, and only the same data is detected as the data of the acquired image pattern. As a result, noise caused by the color difference can be removed.
[0017]
Each of the above-described image detection methods of the present invention has the following features as preferred embodiments.
The step of scanning the inspection area, the step of sequentially storing the data of the acquired image pattern along with the scanning of the inspection area, and comparing the data of the acquired image pattern with respect to the same chip area on the semiconductor wafer. Detecting the defect data, and transmitting the acquired image pattern including the defect data in the output step.
[0018]
A semiconductor device according to the present invention is formed through the use of any of the above-described semiconductor wafer inspection devices or image detection methods. It contributes to mass production of highly reliable semiconductor devices.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram showing a main configuration of a semiconductor wafer inspection apparatus according to the first embodiment of the present invention. The semiconductor wafer 10 includes those in the process of manufacturing a semiconductor process, and a predetermined pattern of a chip region is repeatedly arranged with a line (not shown) therebetween. The stage 11 supports the semiconductor wafer 10 horizontally and can move in the X and Y directions. This contributes to the movement of the inspection location on the semiconductor wafer 10.
[0020]
The broadband light source 12 is, for example, a halogen lamp or the like, and irradiates the semiconductor wafer 10 with the broadband light Lin via the optical system 13. That is, the inspection area on the semiconductor wafer 10 is irradiated with the broadband light through the various lenses L, the half mirror HM, and the like to obtain the reflected light Lre. The filter mechanism 14 includes the color filters 141 to 143, and narrows the reflected light Lre in the inspection fixed area to three or more types. More specifically, the output is divided into wavelength bands of three primary colors (R, G, B).
[0021]
The signal processing unit 15 digitizes the separated signals of each wavelength band. For example, it includes a CCD and an A / D converter, and A / D converts and outputs a signal passed through the CCD. The comparison operation mechanism 16 includes a buffer memory, accumulates the data Dr, Dg, and Db of each wavelength band obtained by the signal processing unit 15, and sequentially compares data having the same positional relationship, and finds the identical data. Only data is detected as acquired image pattern data. The output unit 17 finally makes a pattern corresponding to the data of the acquired image pattern into a graphic and displays it on a monitor.
[0022]
The control unit 18 controls the movement of the inspection location on the semiconductor wafer 10 by the stage 11, and further controls at least the signal processing unit 15, the comparison operation mechanism 16, and the output unit 17. The inspection area may be set based on externally provided coordinate data. The coordinate data may be determined according to already known defect data, or may be determined when an inspection location is specified in advance. It is also conceivable that the inspection area is a scanning area for a plurality of chips.
[0023]
FIG. 2 is a flowchart showing an image detection method using the configuration of FIG. In step S101, the inspection area on the semiconductor wafer is irradiated with broadband light. In the process S102, the reflected light in the inspection fixed area is narrowed, that is, separated into three wavelength bands of three primary colors. In step S103, each wavelength band is converted into data, that is, converted into a digital signal. In step S104, data in each wavelength band is compared. As a result, only the same data that matches the data in each wavelength band is detected as the data of the acquired image pattern (process S105).
[0024]
According to the first embodiment and the image detection method, the inspection area is irradiated with broadband light, the reflected light is divided into various color components by the filter mechanism 14, and each is digitized by the signal processing unit 15. The comparison operation mechanism 16 compares these data and detects only the same data as the data of the acquired image pattern. As a result, noise caused by the color difference can be removed. As a result, only the necessary pattern is recognized, and the displayed graphic pattern is much easier to confirm than in the past.
[0025]
FIG. 3 is a block diagram showing a main configuration of a semiconductor wafer inspection apparatus according to the second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals. Compared with the configuration of FIG. 1, a system for performing defect detection by a comparative inspection on each chip area is added. Therefore, the memory unit 21 and the arithmetic and control unit 22 are shown as main components. The other configuration is the same as that of the first embodiment, and therefore the following description will focus on the different configuration.
[0026]
With respect to the inspection area on the semiconductor wafer, the movement of the stage 11 is controlled by the control unit 18 so that adjacent chip areas are sequentially scanned. The memory unit 21 sequentially stores the data of the acquired image pattern obtained by the comparison operation mechanism 16 as the inspection area is scanned. The arithmetic and control unit 22 compares the data of the acquired image patterns with respect to two or more identical chip regions on the semiconductor wafer 10 and detects defect data determined as different levels. The output unit 17 receives data of the acquired image pattern having a defect in the inspection area. As a result, the output unit 17 makes a pattern including the defect area corresponding to the data of the acquired image pattern into a graphic and displays the graphic on a monitor.
[0027]
FIG. 4 is a flowchart showing an image detection method using the configuration of FIG. The inspection area is set to a predetermined scanning area, and the processing up to step S105 for detecting the data of the acquired image pattern is the same as that in FIG. Here, in the processing S106, the data of the acquired image patterns is compared for two or more same chip areas. As a result, defect data determined as different levels is detected (step 107).
[0028]
According to the second embodiment and the image detection method, the inspection region on the semiconductor wafer sequentially becomes a scanning region of the adjacent chip region, the irradiated broadband reflected light is divided into various color components by the filter mechanism 14, and each is subjected to a signal. It is digitized by the processing unit 15. The comparison operation mechanism 16 compares these data and detects only the same data as the data of the acquired image pattern. As a result, data from which noise due to the color difference has been removed is obtained. Two or more identical chip areas are compared using the acquired image pattern data. Thereby, defect data determined as different levels is detected. As a result, the comparison between adjacent chip regions or further identical chip regions is performed using data from which noise has been eliminated, and the accuracy and reliability are improved. Further, only the necessary pattern is recognized, and the displayed graphic pattern is much easier to confirm than in the past.
[0029]
FIG. 5 is a block diagram showing a main configuration of a semiconductor wafer inspection apparatus according to a third embodiment of the present invention. The same parts as those in the first embodiment will be described with the same reference numerals. The semiconductor wafer 10 is horizontally supported by the stage 11 and can be moved in the X and Y directions by the control unit 38. This contributes to the movement of the inspection location on the semiconductor wafer 10.
[0030]
The short-wavelength light source 32 emits, for example, three types of short-wavelength lights Lin1 to 3 at predetermined timings. The short-wavelength light source 32 is, for example, a mercury lamp or the like. By using filters of respective wavelengths, the g-line (λ = 436 nm), the h-line (λ = 405 nm), and the i-line (λ = 365 nm) are emitted at a predetermined timing. Fire. That is, the inspection area on the semiconductor wafer 10 is irradiated with each of the short-wavelength lights Lin1 to 3 through the optical system 33 (various lenses L, half mirrors HM, etc.) to obtain the reflected lights Lre1 to Lre3.
[0031]
The signal processing unit 35 converts the reflected light Lre1 to Lre3 of each short-wavelength light into data, that is, digitizes the reflected light Lre1. For example, a CCD and an A / D converter are provided corresponding to each short-wavelength light, and a signal via the CCD is A / D converted and output. The comparison operation mechanism 36 includes a buffer memory, accumulates the data D1, D2, and D3 of each wavelength band obtained by the signal processing unit 35, sequentially compares the data having the same positional relationship, and matches each other. Only the same data is detected as the data of the acquired image pattern. The output unit 37 finally makes a pattern corresponding to the data of the acquired image pattern into a graphic and displays it on a monitor.
[0032]
The control unit 38 controls the movement of the inspection location on the semiconductor wafer 10 by the stage 11, and further controls at least the signal processing unit 35, the comparison operation mechanism 36, and the output unit 37. The inspection area may be set based on externally provided coordinate data. The coordinate data may be determined according to already known defect data, or may be determined when an inspection location is specified in advance. It is also conceivable that the inspection area is a scanning area for a plurality of chips.
[0033]
FIG. 6 is a flowchart showing an image detection method using the configuration of FIG. In step S201, at least three types of short-wavelength light are applied to an inspection area on a semiconductor wafer. In step S202, the reflected light in the inspection and determination area is converted into data, that is, converted into a digital signal. In step S203, the data of each short-wavelength light is compared. As a result, only the same data in which the data of each short wavelength light matches is detected as the data of the acquired image pattern (process S204).
[0034]
According to the third embodiment and the image detection method, the inspection area is irradiated with short-wavelength light, and each reflected light is digitized by the signal processing unit 35. The comparison operation mechanism 36 compares these data and detects only the same data as the data of the acquired image pattern. As a result, noise caused by the color difference can be removed. As a result, only the necessary pattern is recognized, and the displayed graphic pattern is much easier to confirm than in the past.
[0035]
FIG. 7 is a block diagram showing a main part configuration of a semiconductor wafer inspection apparatus according to a fourth embodiment of the present invention. The same parts as those in the third embodiment are denoted by the same reference numerals. Compared with the configuration of FIG. 5, a system for performing defect detection by comparison inspection for each chip area is added. For this reason, the memory unit 41 and the arithmetic and control unit 42 are shown as main components. Other configurations are the same as those of the third embodiment, and therefore, the following description will focus on different configurations.
[0036]
With respect to the inspection area on the semiconductor wafer, the movement of the stage 11 is controlled by the control unit 18 so that adjacent chip areas are sequentially scanned. The memory unit 41 sequentially stores the data of the acquired image pattern obtained by the comparison operation mechanism 36 as the inspection area is scanned. The arithmetic and control unit 42 compares the data of the acquired image patterns with respect to two or more same chip regions on the semiconductor wafer 10 and detects defect data determined as different levels. The data of the acquired image pattern having a defect in the inspection area is transmitted to the output unit 37. As a result, the output unit 37 makes the pattern including the defect area corresponding to the data of the acquired image pattern into a graphic and displays the graphic on the monitor.
[0037]
FIG. 8 is a flowchart showing an image detection method using the configuration of FIG. The inspection region is set to a predetermined scanning region, and the process up to step S204 for detecting the data of the acquired image pattern is the same as that in FIG. Here, in the process S205, the data of the obtained image patterns is compared for two or more same chip regions. Thereby, defect data determined as different levels is detected (process 206).
[0038]
According to the fourth embodiment and the image detection method, the inspection area on the semiconductor wafer sequentially becomes the scanning area of the adjacent chip area, and each of the irradiated short-wavelength lights is digitized by the signal processing unit 35. The comparison operation mechanism 36 compares these data and detects only the same data as the data of the acquired image pattern. As a result, data from which noise due to the color difference has been removed is obtained. Two or more identical chip areas are compared using the acquired image pattern data. Thereby, defect data determined as different levels is detected. As a result, the comparison between adjacent chip regions or further identical chip regions is performed using data from which noise has been eliminated, and the accuracy and reliability are improved. Further, only the necessary pattern is recognized, and the displayed graphic pattern is much easier to confirm than in the past.
[0039]
As described above, according to the present invention, an inspection area on a semiconductor wafer is irradiated with broadband light to separate it into at least three types of narrow wavelengths, or at least three types of short wavelength light are applied to the inspection area in advance. It has the configuration to do. Any one of such optical signals is subjected to signal processing and compared by the comparison operation mechanism, and only the same data is detected as data of the acquired image pattern. As a result, noise caused by the color difference can be removed. As a result, only the necessary pattern is recognized, and the displayed graphic pattern is much easier to confirm than in the past. In the defect inspection, the accuracy and reliability can be improved and the inspection speed can be expected to be improved. As a result, it is possible to provide a semiconductor wafer inspection device and an image detection method capable of detecting or recognizing a desired pattern on a wafer without noise, and a semiconductor device formed through the use thereof.
[Brief description of the drawings]
FIG. 1 is a block diagram of a main configuration of a semiconductor wafer inspection apparatus according to a first embodiment.
FIG. 2 is a flowchart showing an image detection method using the configuration of FIG.
FIG. 3 is a block diagram of a main configuration of a semiconductor wafer inspection device according to a second embodiment.
FIG. 4 is a flowchart showing an image detection method using the configuration of FIG. 3;
FIG. 5 is a block diagram of a main part configuration of a semiconductor wafer inspection device according to a third embodiment.
FIG. 6 is a flowchart showing an image detection method using the configuration of FIG. 5;
FIG. 7 is a block diagram of a main part configuration of a semiconductor wafer inspection device according to a fourth embodiment.
FIG. 8 is a flowchart showing an image detection method using the configuration of FIG. 7;
[Explanation of symbols]
Reference Signs List 10: semiconductor wafer, 11: stage, 12: broadband light source, 13, 33: optical system, 14: filter mechanism, 141 to 143: color filter, 15, 35: signal processing unit, 16, 36: comparison operation mechanism, 17 , 37 ... output unit, 18, 38 ... control unit, 32 ... short wavelength light source, S101 to S107, S201 to S206 ... each processing step.

Claims (14)

An illumination optical system that irradiates an inspection area on a semiconductor wafer with broadband light to obtain reflected light,
A filter mechanism that divides the reflected light of the inspection and determination area into three or more types of wavelength bands and outputs the divided light;
A signal processing unit for digitizing the signal of each wavelength band,
A comparison operation mechanism that compares data of each wavelength band obtained by the signal processing unit and detects the same data as data of an acquired image pattern,
An output unit for at least the obtained image pattern,
A semiconductor wafer inspection device, comprising: 2. The semiconductor wafer inspection apparatus according to claim 1, wherein the inspection area is set based on externally provided coordinate data. 2. The semiconductor wafer inspection apparatus according to claim 1, wherein the inspection area is a scanning area for a plurality of chips on the semiconductor wafer. A stage that supports the semiconductor wafer and controls movement so that the inspection area is scanned,
A memory unit that sequentially stores data of the acquired image pattern detected by the comparison operation mechanism along with scanning of the inspection area,
An arithmetic control mechanism for comparing data of the acquired image patterns for the same chip region on the semiconductor wafer and detecting different defect data,
Including
2. The semiconductor wafer inspection apparatus according to claim 1, wherein the acquired image pattern including the defect data is transmitted to the output unit. 5. The semiconductor wafer inspection apparatus according to claim 1, wherein each of the three or more types of wavelength bands is a wavelength band of three primary colors (R, G, B). An illumination optical system that irradiates three or more different types of short-wavelength light to an inspection area on a semiconductor wafer to obtain respective reflected light;
A signal processing unit that converts the reflected light of each of the short-wavelength lights into data in the inspection area,
A comparison operation mechanism that compares data of each short-wavelength light obtained by the signal processing unit and detects the same data as data of an acquired image pattern,
An output unit for at least the obtained image pattern,
A semiconductor wafer inspection device, comprising: 7. The semiconductor wafer inspection apparatus according to claim 6, wherein the inspection area is set based on externally provided coordinate data. 7. The semiconductor wafer inspection apparatus according to claim 6, wherein the inspection area is a scanning area for a plurality of chips on the semiconductor wafer. A stage that supports the semiconductor wafer and controls movement so that the inspection area is scanned,
A memory unit that sequentially stores data of the acquired image pattern detected by the comparison operation mechanism according to the scanning of the inspection area,
An arithmetic control mechanism for comparing data of the acquired image patterns for the same chip region on the semiconductor wafer and detecting different defect data,
Including
7. The semiconductor wafer inspection apparatus according to claim 6, wherein the acquired image pattern including the defect data is transmitted to the output unit. Irradiating the inspection area on the semiconductor wafer with broadband light;
Dividing the reflected light of the inspection area into three or more wavelength bands;
A step of converting each wavelength band into data,
Comparing the data of each wavelength band, detecting the same data as data of the acquired image pattern,
An output step for at least the obtained image pattern,
An image detection method comprising: Irradiating an inspection area on a semiconductor wafer with three or more types of different short-wavelength lights at predetermined timings respectively;
A step of converting the reflected light of each of the short-wavelength lights into data in the inspection area,
Comparing the data of each wavelength band, detecting the same data as data of the acquired image pattern,
An output step for at least the obtained image pattern,
An image detection method comprising: Scanning the inspection area;
A step of sequentially storing the data of the acquired image pattern with the scanning of the inspection area,
A step of comparing data of the obtained image pattern for the same chip region on the semiconductor wafer and detecting different defect data,
Including
12. The image detection method according to claim 10, wherein the acquired image pattern including the defect data is transmitted in the output step. A semiconductor device formed through the use of the semiconductor wafer inspection device according to claim 1. A semiconductor device formed by utilizing the image detection method according to claim 10.

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