JP4872438B2 - Inspection device, inspection method, and inspection processing program - Google Patents

Description

  The present invention relates to a technical field such as an inspection apparatus that inspects exposure unevenness, coating unevenness, and the like on an inspection object such as a wafer.

  In the manufacture of an on-chip color filter used for an image sensor device such as a CCD or CMOS, for example, a resist (also referred to as a color resist) is applied on a planarizing film applied on a semiconductor wafer (for example, a Si substrate). Then, the coated resist is exposed (for example, the wafer is divided into regions and divided exposure is performed, the same applies hereinafter), and then developed. Thereby, a desired color filter pattern, that is, a first on-chip color filter (first color, for example, green) is formed on the planarizing film.

  Thereafter, a resist is further applied on the planarizing film, and this is exposed and developed. Thereby, a desired color filter pattern, that is, a second on-chip color filter (second color, for example, red) is formed on the planarizing film.

  Thereafter, a resist is further applied on the planarizing film, and the resist is exposed and developed. Thereby, a desired color filter pattern, that is, a third on-chip color filter (third color, for example, blue) is formed on the planarizing film.

  In such a thin film coating process such as resist, coating (film thickness) unevenness (non-uniform film thickness) occurs, and in the divided exposure process, exposure unevenness occurs, and these unevenness deteriorates the quality of the product, Conventionally, various proposals have been made so as not to cause such unevenness.

On the other hand, several methods for visualizing or inspecting the film thickness unevenness of a thin film applied by a die coating method or a spin coating method have been proposed (see, for example, Patent Documents 1 to 3).
Japanese Patent No. 3631856 Japanese Patent No. 3114972 JP-A-9-292207

  However, in the conventional inspection method, since the unevenness as described above is insensitive, it has been difficult to quantitatively evaluate.

  Further, in the conventional inspection method, visualization is a technology that only emphasizes and displays an image with a contrast that makes it easy for a person to recognize the unevenness, and general unevenness inspection is a technology that extracts a region having a different contrast with the surroundings. However, it did not evaluate the strength of unevenness.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an inspection apparatus, an inspection method, and an inspection processing program capable of quantitatively evaluating unevenness in an object to be inspected.

In order to solve the above-mentioned problem, the invention according to claim 1 is an inspection apparatus for inspecting coating unevenness on the surface of a wafer, and an image acquisition unit that acquires data of a surface image obtained by photographing the surface of the wafer ; a polar coordinate conversion means for polar coordinate conversion data of the acquired surface image, a luminance average value calculation means for calculating an average value of the luminance of each pixel in a plurality of areas on the polar coordinate conversion surface image, the polar coordinate conversion Area dividing means for dividing the surface image into a large area including the plurality of areas, and a maximum luminance value and a minimum luminance value among the average luminance values of the respective areas included in the divided large area. , determined in large area every time the divided, a contrast calculating means from the said maximum brightness value and the minimum luminance value you calculate a value representing the contrast of each of the large region, a value representing the contrast Hisage Characterized in that it comprises a presenting means for the.

According to a second aspect of the present invention, in the inspection apparatus according to the first aspect of the present invention, for the surface image that has been subjected to the polar coordinate conversion, a band-shaped inspection exclusion region and an inspection region are set separately in the polar coordinate system. Further comprising an exclusion area setting means, wherein the luminance average value calculation means excludes the exclusion inspection area and calculates the average value of the luminance in a plurality of areas on the polar coordinate-converted surface image. To do.

The invention according to claim 3 is an inspection apparatus for inspecting exposure unevenness on the surface of a wafer on which a chip is formed, the image acquisition means for acquiring data of a surface image obtained by photographing the surface of the wafer, and the surface Luminance average value calculating means for calculating an average luminance value of each pixel in a plurality of chips on the image, and the surface image is divided into a large area including the plurality of chips and a large area for each exposure unit. A maximum luminance value and a minimum luminance value are obtained for each of the divided large areas from the area dividing means and the average value of the luminance of each chip included in the divided large area. The image processing apparatus includes: a contrast calculating unit that calculates a value representing the contrast for each large region from the minimum value; and a presenting unit that presents the value representing the contrast .

According to a fourth aspect of the present invention, the inspection apparatus according to any one of the first to third aspects further includes a contrast average value calculating unit that calculates an average value of the values representing the contrast for each large region. It is characterized by that.

Invention according to claim 5, in the inspection apparatus according to any one of claims 1 to 4, the value representative of the contrast, or the defect determination means average value thereof to determine whether it exceeds the threshold value Further, the presenting means presents that it is defective when the threshold value is exceeded.

The invention of an inspection processing program according to claim 6 causes a computer to function as the inspection apparatus according to any one of claims 1 to 5 .

The invention according to claim 7 is an inspection method for inspecting coating unevenness on the surface of a wafer, an image acquisition step of acquiring data of a surface image obtained by photographing the surface of the wafer , and data of the acquired surface image a polar coordinate conversion step of polar coordinate conversion, a luminance average value calculation step of calculating an average value of the luminance of each pixel in a plurality of areas on the polar coordinate conversion surface image, the polar coordinate conversion surface image, the An area dividing step of dividing into a large area including a plurality of areas, and a luminance maximum value and a luminance minimum value from among the average luminance values of the areas included in the divided large area, the divided large area found for each, including a contrast calculating step of calculating a value representing the contrast of each of the large area and a the maximum luminance value and minimum luminance value, and a presentation step of presenting a value representing the contrast It is characterized in.

  According to the present invention, surface image data obtained by photographing the surface of the object to be inspected is obtained, luminance values in a plurality of regions on the surface image are calculated, and the contrast in the region is calculated based on the luminance values. Since the value representing the contrast is calculated and the value representing the contrast is configured to be presented, the inspector can confirm the intensity (degree) of unevenness in the object to be inspected numerically. Quantitative evaluation of unevenness can be performed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best mode for carrying out the invention will be described with reference to the drawings. The embodiment described below is an embodiment in which the present invention is applied to an inspection system for inspecting unevenness or the like in an object to be inspected, and a wafer for forming an on-chip color filter is applied as the object to be inspected. is there.

  First, with reference to FIG.1 and FIG.2, the structure and function of the test | inspection system which concern on this embodiment are demonstrated.

  FIG. 1 is a diagram showing an example of the appearance of an inspection system according to the present embodiment, and FIG. 2 is a diagram showing an example of functional blocks of main parts in a control device 1 included in the inspection system.

  An inspection system S shown in FIG. 1 includes a control device 1, a display unit (having a display) 2, a light source (for example, a metal halide lamp) 3, an optical fiber 4, an illumination (light projection) unit (for example, a quartz rod) 5, and a photosensitive device. A wavelength cut filter 6, a line sensor camera (imaging means) 7, a band pass filter 8, a stage (work transfer stage) 9 and the like are provided.

  A display unit 2, a light source 3, a line sensor camera 7, a stage 9, and the like are electrically connected to the control device 1 by a dedicated cable. The control device 1 controls these components, and It also functions as an inspection device of the invention. Note that an illumination unit 5 is connected to the light source 3 via an optical fiber 4.

  Then, under the control of the control device 1 (control unit 11), the inspection system S emits light from the illumination (light projection) unit 5 to the surface of the wafer W as the object to be inspected placed on the stage 9. While irradiating (through the photosensitive wavelength cut filter 6 as necessary), the line sensor camera 7 images the surface (images through the bandpass filter 8), and the surface image data is used as the control device 1. It is acquired by the image processing unit 12 provided for. Note that the filter switching unit 15 illustrated in FIG. 2 switches a plurality of filters (for example, a filter that extracts different single lights) in the band-pass filter 8 under the control of the control device 1.

  Further, the control device 1 includes a control unit 11 and an image processing unit 12 shown in FIG. 2, and further, the above-described surface image data, various setting data, OS (operating system) and application program (inspection processing of the present invention). A storage unit (including a hard disk, a ROM, a working RAM, a video RAM, etc.) for storing a program (including a program) and an operation instruction from an inspector (operator) are input, and the instruction signal is input to the control unit 11 or An operation unit (for example, a keyboard, a mouse, etc.) that outputs to the image processing unit 12 is provided.

  The image processing unit 12 is configured mainly with a CPU, and executes a program stored in the storage unit, whereby an image acquisition unit, a contrast calculation unit, a region division unit, a contrast average value calculation unit, a defect in the present invention An application (film thickness) unevenness determination process that functions as a determination means, a presentation means, and the like, and determines application (film thickness) unevenness generated in a thin film application process such as a resist and a protective film on the wafer W, which will be described later, and An exposure unevenness determination process for determining the exposure unevenness generated in the divided exposure process is executed.

  Next, the operation of the inspection system S according to the present embodiment will be described.

(1. Exposure unevenness determination processing)
First, the exposure unevenness determination process will be described with reference to FIGS.

  3 and 4 are flowcharts showing exposure unevenness determination processing in the image processing unit 12, FIG. 3 shows determination processing for each exposure unit on the wafer W, and FIG. 4 shows determination processing for the entire wafer W. Show. FIG. 5 is a view showing a plurality of chips C formed on the wafer W, and FIG. 6 is a view for explaining details of processing in each step.

  First, the determination process for each exposure unit shown in FIG. 3 will be described.

  The wafer W that has been divided and exposed is placed and transported on the stage 9, and when it reaches a predetermined position, as described above, the surface is photographed by the line sensor camera 7, and the data of the surface image is transferred to the control device 1. Is input to the image processing unit 12 (step S1) and developed on the RAM.

  Next, the image processing unit 12 calculates an average brightness value in the chip C (an example of a region) on the input surface image (step S2). That is, the image processing unit 12 calculates the luminance value of each pixel in the area occupied by the chip C as shown in FIG. 6A, averages the calculated luminance values, and calculates the average luminance value. To remember.

  Next, the image processing unit 12 determines whether or not the calculation of the luminance average value has been completed for all the chips C on the surface image (step S3), and if not completed (step S3: No) The process returns to step S2, and when the process ends (step S3: Yes), the process proceeds to step S4. In this way, the average luminance value is calculated for all the chips C on the surface image.

  In step S4, the image processing unit 12 divides the surface image into a large area including a plurality of chips C and a large area for each exposure unit (hereinafter referred to as “divided area”).

  Here, the divided exposure is performed by dividing the wafer W while scanning it over a plurality of times, and one exposure (one shot) is referred to as an exposure unit. For example, the example in FIG. Then, one divided area A is an area including nine chips C. The size of the divided area A is determined by the exposure unit.

  Next, the image processing unit 12 selects the maximum value (hereinafter referred to as “luminance maximum value”) and the minimum value (hereinafter referred to as “luminance minimum”) from the average luminance value of each chip C included in the divided area A. A value D representing the contrast in the divided area A is calculated from the maximum luminance value Max and the minimum luminance value Min (step S5), and the calculated value D representing the contrast is stored in the RAM.

  The value D representing the contrast is calculated by, for example, the following formula (1) (normalization formula).

D = (Max−Min) / (Max + Min) * 100 (1)
The value D representing the contrast calculated by the equation (1) changes within a range of 0 to 100, but the closer the D is to “0”, the more uniform and uniform it is. It can be said that the closer to “100”, the stronger the unevenness. The normalization method is not limited to 0 to 100, and may be 0 to 1. Further, it may be calculated so that “0” represents a strong unevenness and “100” represents a uniform state.

  Next, the image processing unit 12 displays (presents) the value D representing the calculated contrast on the display in the display unit 2 (step S6).

  Next, the image processing unit 12 determines whether or not the value D representing the calculated contrast exceeds a preset threshold value. If the value D exceeds the predetermined threshold value, the image processing unit 12 determines that the value is defective and displays that the value is defective. (It may be presented by voice) (step S7).

  Note that only one of step S6 and step S7 may be performed.

  Next, the image processing unit 12 determines whether or not the calculation of the value D representing the contrast has been completed for all the divided areas A on the surface image (step S8), and if not completed (step S8: No), the process returns to step S5 (the same process is repeated), and when the process ends (step S8: Yes), the process ends.

  Thus, the value D representing the contrast for each divided area A on the surface image is calculated, and the value D representing the contrast of each divided area A is displayed on the display in the display unit 2 (for example, the position (for each divided area A ( For example, a list of values D representing contrast in association with the center position) is presented to the examiner.

  Thereby, the inspector can confirm the exposure unevenness for each exposure unit numerically, the setting of the inspection standard becomes clear, the comparison of the exposure unevenness between different divided areas A, and the exposure unevenness between different wafers W. Comparison can be easily performed. Further, the inspector can easily determine whether or not each divided area A is defective. Therefore, the inspector can easily adjust the exposure apparatus according to the inspection result.

  Note that a surface image in which the divided area A is shown on the wafer W as shown in FIG. 6C is displayed on the display in the display unit 2, and a value D representing the contrast of the area A is displayed on each divided area A. Alternatively, if it is defective, the fact may be displayed in association (superimposed display). If comprised in this way, it can be grasped | ascertained very easily which position on the wafer W has strong exposure unevenness, and which position is defective.

  Next, the determination process for the entire wafer W shown in FIG. 4 will be described.

  Note that the processing in steps S11 to S15 in FIG. 4 is the same as the processing in steps S1 to S5 in the processing in FIG.

  When the value D representing the contrast of the divided area A is calculated in the process of step S15 in FIG. 4, in step S16, the image processing unit 12 sets the value D representing the contrast for all the divided areas A on the surface image. It is determined whether or not the calculation is completed (step S16). If the calculation is not completed (step S16: No), the process returns to step S15. If the calculation is completed (step S16: Yes), the process proceeds to step S17. .

  In step S17, the average value of the values D representing the contrast of the entire divided area A is calculated by averaging the values D representing the contrast for each divided area A calculated in step S15, and the calculated average value is stored in the RAM. To remember.

  Next, the image processing unit 12 displays (presents) the average value of the values D representing the calculated contrast on the display in the display unit 2 (step S18).

  Next, the image processing unit 12 determines whether or not the average value of the values D representing the contrast exceeds a preset threshold value, and if it exceeds, the entire wafer W (the entire workpiece) is defective. It judges, displays that it is unsatisfactory (it may be made to present with an audio | voice) (step S19), and complete | finishes the said process.

  Thereby, the inspector can confirm the exposure unevenness of the entire wafer W by a numerical value, the setting of the inspection standard becomes clear, and the exposure unevenness between different wafers W can be easily compared. Further, the inspector can easily determine whether or not each wafer W is defective. Therefore, the inspector can easily adjust the exposure apparatus according to the inspection result.

(2. Coating unevenness determination processing)
Next, the coating unevenness determination process will be described with reference to FIGS.

  FIG. 7 is a flowchart showing application unevenness determination processing in the image processing unit 12. FIG. 8 is a conceptual diagram of polar coordinate conversion, and FIG. 9A is a conceptual diagram showing a result of polar coordinate conversion of a surface image of a wafer W having concentric unevenness on the surface, and FIG. FIG. 9 is a conceptual diagram showing a polar coordinate transformation of a surface image of a wafer W having radial unevenness on the surface, and FIG. 9C shows an abnormal center film thickness (hereinafter also referred to as “central unevenness”) on the surface. It is a conceptual diagram which shows what carried out polar coordinate conversion of the surface image of the wafer W which has. FIG. 10 is a diagram for explaining details of concentric unevenness extraction processing and radial unevenness extraction processing, and FIG. 11 is a diagram for explaining details of central portion unevenness extraction processing.

  For example, a wafer W coated with a resist is placed on the stage 9 and conveyed, and when it comes to a predetermined position, as described above, the surface is photographed by the line sensor camera 7 and the data of the surface image is controlled. The image data is input to the image processing unit 12 in the apparatus 1 (step S31) and developed on the RAM.

  Here, as an example of the types of coating unevenness to be determined in the coating unevenness determination process, as shown in FIGS. 9A to 9C, concentric circular unevenness, radial unevenness, and central film thickness abnormality (center) These unevennesses are, for example, film thickness unevenness (non-uniform film thickness) applied by a known spin coating method. In the known spin coating method, for example, a wafer is rotated while being held horizontally by a rotating means, an appropriate amount of resist is dropped on a substantially central portion of the wafer by a nozzle, and the resist flows toward the outer peripheral edge of the wafer by centrifugal force. However, since the thin film is formed, such unevenness is generated.

  Next, the image processing unit 12 performs polar coordinate conversion (converted from XY coordinates to polar coordinates) on the input surface image (step S32).

  FIG. 8 shows a conceptual diagram of polar coordinate conversion based on the following formulas (2) and (3) (general formula).

x = rcosθ (2)
y = rsinθ (3)
In actual image processing, the input surface image is subjected to polar coordinate conversion by the following equations (4) and (5).

x = y'cos (2πx '/ W) + Cx (4)
y = y'sin (2πx '/ W) + Cy (5)
Here, x and y are the coordinates of the original (before conversion) image, x ′ and y ′ are the coordinates of the image after conversion, W is the width of the image after conversion, and Cx and Cy are the coordinates on the original image. The coordinates that are the center of the polar coordinate system are shown.

  That is, from the above equations (4) and (5), the pixel value of the coordinate (x ′, y ′) on the image after conversion corresponds to the coordinate (x, y) of the original image as shown in FIG. The pixel value to be

  Thus, when the coating unevenness is, for example, concentric unevenness, the polar coordinates are converted as shown in FIG. 9A, and the linear stripe 51 appears in the horizontal direction. Further, when the coating unevenness is, for example, radial unevenness, polar coordinates are converted as shown in FIG. 9B, and a linear streak 52 appears in the vertical direction. In addition, when the coating unevenness is, for example, central portion unevenness, polar coordinate conversion is performed as shown in FIG. 9C, and a strip-shaped region 53 appears in the lower horizontal direction.

  Next, the image processing unit 12 sets a dead zone (inspection exclusion region) for the surface image subjected to polar coordinate conversion (that is, distinguishes between the inspection region and the inspection exclusion region) (step S33). For example, a reference numeral 54 (black portion) in FIGS. 9A to 9C is a dead zone, and corresponds to the outside of the work edge (that is, the edge of the wafer W).

  Next, concentric unevenness extraction processing, radial unevenness extraction processing, or central portion unevenness extraction processing is performed. Among these, which process is performed can be selected and set by the inspector from the operation unit, for example, and any process is selected and executed according to the setting.

  For example, in the case of concentric unevenness extraction processing, the image processing unit 12 performs vertical differentiation (subjects to a high-pass filter in the vertical direction) on the inspection area of the surface image subjected to the polar coordinate conversion (step S34). By such differentiation processing, for example, the luminance of the streak 51 shown in FIG. 9A is enhanced.

  Next, the image processing unit 12 divides the surface image in the inspection region (inspection range) obtained by longitudinal differentiation into a plurality of rectangular regions CX as shown in FIG. 10A, and calculates the average luminance value of each rectangular region CX. Calculate (by the same calculation as the luminance average value of the chip C in step S2 described above) (step S35) and store.

  Next, the image processing unit 12 sets a divided area AX (an example of a large area) including a plurality of (for example, nine) rectangular areas CX (step S36).

  Next, the image processing unit 12 obtains the maximum luminance value Max and the minimum luminance value Min from the average luminance value of each rectangular area CX included in the set divided area AX, and the maximum luminance value Max and the minimum luminance value. A value D representing the contrast in the divided area AX is calculated from the value Min by, for example, the above equation (1) (step S37), and the calculated value D representing the contrast is stored in the RAM.

  Next, the image processing unit 12 determines whether or not the calculation of the value D representing the contrast has been completed for the entire inspection region (step S38), and if not completed (step S38: No), the process proceeds to step S36. Returning to FIG. 10B, a new divided area AX is set so that a part of the set divided area AX overlaps (overlaps) the original divided area AX, and the process of step S37 is performed. I do. Thus, such processing is repeatedly performed while the divided area AX is gradually shifted until the calculation of the value D representing the contrast is completed for the entire inspection area.

  Next, when the calculation of the value D representing the contrast is completed for the entire inspection region (Step S38: Yes), the image processing unit 12 converts the center coordinates of each divided region AX from polar coordinates to XY coordinates. Then, the calculated value D representing the contrast for each divided area AX is displayed (presented) on the display in the display unit 2 (step S46). For example, a list of values D representing contrast is displayed in association with the position of each divided area AX (center position converted into XY coordinates). Thus, a value D representing contrast is presented to the examiner.

  Next, the image processing unit 12 determines whether or not the value D representing the contrast exceeds a preset threshold value. If it exceeds, the image processing unit 12 determines that the value is defective and displays that it is defective (note that And may be presented by voice) (step S47), and the process ends. Such determination processing is performed for each of the set divided areas AX.

  Thereby, the inspector can confirm the concentric unevenness for each divided area AX numerically, the setting of the inspection standard becomes clear, the comparison of the concentric unevenness between different divided areas AX, and the different wafers W Comparison of concentric unevenness between each other can be easily performed. Further, the inspector can easily determine whether or not each divided area AX is defective. Therefore, the inspector can easily adjust the coating apparatus according to the inspection result.

  Note that only one of step S46 and step S47 may be performed.

  Further, a surface image as shown in the upper part of FIG. 9A is displayed on the display in the display unit 2, and the contrast of each divided area AX is displayed on the center position converted into the XY coordinates of each divided area AX. It may be configured such that the value D to be expressed or, if it is defective, is displayed in a correlated manner (superimposed display). With this configuration, it is very easy to grasp which position on the wafer W is strong in concentric circles and which position is defective.

  In addition, the image processing unit 12 calculates an average value of the values D representing the contrast for each of the calculated divided areas AX, and presents (for example, displays) the values, and further averages the values D representing the contrasts. It is determined whether or not the value exceeds a preset threshold value. If the value exceeds the threshold, it is determined that the entire wafer W (the entire workpiece) is defective, and the fact that it is defective is displayed (for example, displayed). It may be configured. Concentric unevenness of the entire wafer W can be confirmed numerically, and comparison of concentric unevenness between different wafers W can be easily performed. Further, the inspector can easily determine whether or not each wafer W is defective.

  On the other hand, for example, in the case of radial unevenness extraction processing, the image processing unit 12 performs lateral differentiation (applies to a horizontal high-pass filter) on the inspection region of the surface image that has been subjected to polar coordinate conversion (step S39). By such differentiation processing, for example, the luminance of the streak 52 shown in FIG. 9B is enhanced.

  In the case of radial unevenness extraction processing, the processing of steps S40 to S43, S46, and S47 is the same as the processing of steps S35 to S38, S46, and S47 in the above concentric unevenness extraction processing. The same effect as the extraction process is achieved.

  On the other hand, for example, in the case of the center unevenness extraction process, the image processing unit 12 integrates and projects the luminance value in the horizontal direction as shown in FIG. 11A, for example, as shown in FIG. Data is calculated (step S44).

  Next, the image processing unit 12 refers to the calculated projection data of the inspection region, obtains the maximum luminance value Max and the minimum luminance value Min in the inspection region, for example, as illustrated in FIG. A value D representing the contrast in the inspection region is calculated from the value Max and the minimum luminance value Min by, for example, the above equation (1) (step S45), and the calculated value D representing the contrast is stored in the RAM.

  Next, the image processing unit 12 displays (presents) the value D representing the calculated contrast in the inspection region on the display in the display unit 2 (step S46).

  Next, the image processing unit 12 determines whether or not the calculated value D representing the contrast in the inspection region exceeds a preset threshold value. If it exceeds, the image processing unit 12 determines that the value is defective. A message to this effect is displayed (it may be presented by voice) (step S47), and the process is terminated.

  Thereby, the inspector can confirm the central portion unevenness of the entire wafer W by a numerical value, the setting of the inspection standard becomes clear, and the central unevenness of different wafers W can be easily compared. Further, the inspector can easily determine whether or not each wafer W is defective. Therefore, the inspector can easily adjust the coating apparatus according to the inspection result.

  Note that only one of step S46 and step S47 may be performed.

  In addition, as the types of application unevenness to be determined in the application unevenness determination process, concentric unevenness, radial unevenness, and center unevenness are given as examples, but the present invention is not limited to this, and other forms of unevenness In contrast, the coating unevenness determination process can be applied. However, in the case of film thickness unevenness applied by a known die coating method, linear streaky unevenness in the vertical direction or the horizontal direction is mainly used, and the polar coordinate conversion shown in step S32 is unnecessary (the process is passed). )

  As described above, according to the above embodiment, data of a surface image obtained by photographing the surface of the wafer W is acquired, luminance values in a plurality of regions on the surface image are calculated, and, for example, calculation is performed based on the luminance value. Among the plurality of luminance values, the value representing the contrast in the region is calculated from the maximum luminance value and the minimum luminance value, and the value representing the contrast is presented. In addition, the intensity (degree) of exposure unevenness can be confirmed numerically, and therefore, such unevenness can be quantitatively evaluated. If the numerical values are obtained by imaging under the same conditions and calculated, it is possible to compare the intensity of the unevenness between different works.

  In the above embodiment, the case where a wafer on which an on-chip color filter is formed is applied as an example of the object to be inspected. However, the present invention is not limited to this, and unevenness such as exposure unevenness and coating unevenness is determined. For example, the present invention may be applied to a wafer on which an integrated circuit chip is formed.

It is a figure showing an example of appearance of an inspection system concerning this embodiment. It is a figure which shows the example of a functional block of the principal part in the control apparatus 1 contained in a test | inspection system. It is a flowchart which shows the exposure nonuniformity determination process for every exposure unit in the image process part. 4 is a flowchart showing exposure unevenness determination processing for the entire wafer W in the image processing unit 12. 2 is a diagram showing a plurality of chips formed on a wafer W. FIG. It is a figure for demonstrating the detail of the process in each step. 5 is a flowchart showing application unevenness determination processing in the image processing unit 12; It is a conceptual diagram of polar coordinate transformation. (A) is a conceptual diagram showing a polar coordinate conversion of the surface image of the wafer W having concentric unevenness on the surface, and (B) is a polar coordinate conversion of the surface image of the wafer W having radial unevenness on the surface. (C) is a conceptual diagram showing a polar coordinate transformation of a surface image of a wafer W having a central portion unevenness on the surface. It is a figure for demonstrating the detail of a concentric nonuniformity extraction process and a radial nonuniformity extraction process. It is a figure for demonstrating the detail of center part nonuniformity extraction processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Display part 3 Light source 4 Optical fiber 5 Illumination part 6 Photosensitive wavelength cut filter 7 Line sensor camera 8 Band pass filter 9 Stage 11 Control part 12 Image processing part 15 Filter switching part S Inspection system

Claims (7)

An inspection device for inspecting uneven coating on the surface of a wafer ,
Image acquisition means for acquiring data of a surface image obtained by imaging the surface of the wafer ;
Polar coordinate conversion means for converting the acquired surface image data into polar coordinates;
A luminance average value calculation means for calculating an average value of the luminance of each pixel in a plurality of areas on the polar coordinate conversion surface image,
Area dividing means for dividing the polar coordinate-transformed surface image into large areas including the plurality of areas;
A luminance maximum value and a luminance minimum value are obtained for each of the divided large areas from the average luminance values of the respective areas included in the divided large area, and the luminance maximum value and the luminance minimum value are used to calculate the luminance maximum value and the luminance minimum value. a contrast calculating section that to calculate the value indicating the contrast for each large region,
Presenting means for presenting a value representing the contrast;
An inspection apparatus comprising: The inspection apparatus according to claim 1 ,
For the polar coordinate-converted surface image, further comprising inspection exclusion region setting means for distinguishing and setting a strip-shaped inspection exclusion region and an inspection region in the polar coordinate system,
The inspection apparatus according to claim 1, wherein the luminance average value calculation means calculates the average value of the luminance in a plurality of regions on the surface image subjected to the polar coordinate conversion, excluding the excluded inspection region . An inspection device for inspecting exposure unevenness on the surface of a wafer on which a chip is formed,
Image acquisition means for acquiring data of a surface image obtained by imaging the surface of the wafer;
Luminance average value calculating means for calculating an average value of the luminance of each pixel in a plurality of chips on the surface image;
An area dividing means for dividing the surface image into a large area including the plurality of chips and a large area for each exposure unit;
The maximum luminance value and the minimum luminance value are obtained for each of the divided large areas from the average value of the luminance of each chip included in the divided large area, and the maximum luminance value and the minimum luminance value are used to calculate the luminance value. Contrast calculation means for calculating a value representing the contrast of each large area;
Presenting means for presenting a value representing the contrast;
Inspection device, characterized in that it comprises a. The inspection apparatus according to any one of claims 1 to 3,
The inspection apparatus further comprising a contrast average value calculating means for calculating an average value of the values representing the contrast for each large area . The inspection apparatus according to any one of claims 1 to 4,
A failure determination means for determining whether the value representing the contrast or the average value thereof exceeds a threshold;
The presenting means presents that it is defective when the threshold value is exceeded . An inspection processing program for causing a computer to function as the inspection apparatus according to any one of claims 1 to 5 . An inspection method for inspecting uneven coating on the surface of a wafer,
An image acquisition step of acquiring data of a surface image obtained by imaging the surface of the wafer;
Polar coordinate conversion step of converting the acquired surface image data into polar coordinates;
A luminance average value calculating step of calculating an average value of the luminance of each pixel in a plurality of regions on the polar coordinate-converted surface image;
A region dividing step of dividing the polar-coordinated surface image into large regions including the plurality of regions;
A luminance maximum value and a luminance minimum value are obtained for each of the divided large areas from the average luminance values of the respective areas included in the divided large area, and the luminance maximum value and the luminance minimum value are used to calculate the luminance maximum value and the luminance minimum value. A contrast calculation step for calculating a value representing the contrast for each large area;
A presentation step of presenting a value representing the contrast;
The inspection method characterized by including .

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