JP2017034017A - Discharge inspection device, substrate processing apparatus and discharge inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately discriminate a propriety of a discharge operation.SOLUTION: In a discharge inspection part 5 of a substrate processing apparatus, a light emission part 51 emits light along a predetermined light presence surface, such that a plurality of flying substances that are liquids discharged from a plurality of discharge ports are irradiated with the light when the plurality of flying substances pass the light presence surface. An imaging part 52 images the plurality of flying substances passing the light presence surface, such that an inspection image including a plurality of bright points which appear on the plurality of flying substances is acquired. A function storage part stores a plurality of point spread functions corresponding to a plurality of divided regions that are set in the inspection image. An image correction part corrects one or more bright points included in each of the divided regions in the inspection image while using the point spread function corresponding to each of the divided regions, such that a corrected inspection image is acquired. A discrimination part uses the corrected inspection image to discriminate the propriety of discharge operations of liquids from the plurality of discharge ports. Thus, the propriety of the discharge operations in the plurality of discharge ports can be accurately discriminated.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a technique for inspecting a liquid discharge operation from a plurality of discharge ports.

  Conventionally, in a manufacturing process of a semiconductor substrate (hereinafter simply referred to as “substrate”), various processes are performed on a substrate having an insulating film such as an oxide film using a substrate processing apparatus. For example, a cleaning process is performed to remove particles and the like attached on the surface of the substrate by supplying a cleaning liquid to the surface of the substrate.

  In the substrate processing apparatus disclosed in Patent Document 1, cleaning liquid droplets are discharged onto a substrate from a plurality of discharge ports, and the substrate is cleaned. In the substrate processing apparatus, in order to determine the quality of the discharge operation at each of the plurality of discharge ports, the processing liquid discharged from the plurality of discharge ports is irradiated with surface light, and the processing liquid that passes through the surface light An inspection image including a plurality of bright spots is acquired. Then, a plurality of normal discharge determination frames are set on the inspection image, and the quality of the discharge operation at the discharge port corresponding to each normal discharge determination frame is determined based on the presence / absence information of the bright spot in each normal discharge determination frame. The Some of the bright spots in the inspection image are located outside the focus range of the imaging unit, and are blurred (so-called out of focus) on the inspection image compared to other bright spots. Spread greatly. In the substrate processing apparatus, in order to improve the accuracy of the determination of the quality of the discharge operation, as the difference between the inspection distance between the bright spot and the imaging unit and the focusing distance of the imaging unit increases, the normal discharge determination frame The size is reduced.

  On the other hand, Patent Document 2 discloses an image recovery technique for recovering a deteriorated image including image blur in a camera using a point spread function (PSF). Further, in Patent Document 3, when the optical axis of the lens and the central axis of the image sensor are generated and the focus varies in the plane of the image sensor, a point spread function corresponding to each in-plane region of the image sensor is obtained. A technique for performing restoration processing on a captured image by multiplying a portion corresponding to each in-plane region of the captured image is disclosed.

JP 2014-179450 A JP 2004-205802 A JP2013-207752A

  Incidentally, in the substrate processing apparatus of Patent Document 1, as described above, the normal discharge determination frame is reduced with respect to the bright spot located outside the focus range of the imaging unit. There is a limit to improving the accuracy of pass / fail judgment.

  The present invention has been made in view of the above problems, and an object thereof is to accurately determine the quality of a discharge operation.

  The invention according to claim 1 is a discharge inspection device for inspecting the discharge operation of liquid from a plurality of discharge ports, and emits light along a predetermined light existence surface, whereby the plurality of discharge ports A plurality of projectiles that are liquids ejected from the light exiting unit that emits light to the plurality of projectiles when passing through the light-existing surface; and imaging the plurality of projectiles that pass through the light-existing surface By doing so, an imaging unit for acquiring an inspection image including a plurality of bright spots appearing on the plurality of flying objects, and a plurality of point spread functions respectively corresponding to the plurality of divided regions set in the inspection image are stored. A function storage unit, and an image correction unit that obtains a corrected inspection image by correcting one or more bright points included in each divided region of the inspection image using a point spread function corresponding to each divided region; , Using the corrected inspection image And a judging section that judges acceptability of the discharge operation of the liquid from said plurality of outlets.

  A second aspect of the present invention is the ejection inspection apparatus according to the first aspect, wherein the plurality of divided regions have the same shape and size.

  A third aspect of the present invention is the ejection inspection apparatus according to the first aspect, wherein a divided region including a bright spot closest to a focusing position of the imaging unit is set as a reference divided region among the plurality of divided regions. Among the plurality of divided areas, the reference divided area is the largest, and the size of the other areas excluding the reference divided area becomes smaller as the distance from the reference divided area becomes larger.

  A fourth aspect of the present invention is the ejection inspection apparatus according to any one of the first to third aspects, wherein in the divided region including two or more bright spots among the plurality of divided regions, the imaging unit The distance between the two bright spots having the largest distance in the imaging direction is equal to or less than the depth of field of the imaging unit.

  A fifth aspect of the present invention is the ejection inspection apparatus according to any one of the first to third aspects, wherein each of the plurality of divided regions includes only one bright spot.

  A sixth aspect of the present invention is the discharge inspection apparatus according to any one of the first to fifth aspects, wherein the plurality of bright spots in a case where the liquid discharge operations from the plurality of discharge ports are all normal. Is prepared in advance, and each point spread function is an image of one bright spot included in a divided region corresponding to each point spread function when the plurality of divided regions are set in the reference image. .

  A seventh aspect of the invention is the ejection inspection apparatus according to the sixth aspect, wherein when the plurality of divided areas are set in the reference image, the point spread of the divided areas including two or more bright spots The function is an image of one bright spot closest to the center of the divided area among the two or more bright spots.

  The invention according to claim 8 is the discharge inspection apparatus according to any one of claims 1 to 5, wherein the plurality of point spread functions are arranged at positions corresponding to the plurality of divided regions. Is obtained by imaging.

  A ninth aspect of the present invention is the ejection inspection apparatus according to any one of the first to fifth aspects, wherein the plurality of point spread functions are virtually arranged at positions corresponding to the plurality of divided regions. It is obtained by performing a ray tracing calculation on the light emitted from the point light source.

  A tenth aspect of the present invention is a substrate processing apparatus, comprising: a substrate holding portion that holds a substrate; and a discharge head that discharges liquid toward the substrate from a plurality of discharge ports to perform a predetermined process on the substrate. And a discharge inspection apparatus according to claim 1, wherein the discharge operation of the liquid from the plurality of discharge ports of the discharge head is inspected.

  The invention according to claim 11 is a discharge inspection method for inspecting a liquid discharge operation from a plurality of discharge ports, and a) emitting a plurality of light by emitting light along a predetermined light existence surface. A step of irradiating the plurality of flying bodies with light when the plurality of flying bodies, which are liquids discharged from the discharge ports, pass through the light existence plane; and b) the plurality of flying bodies passing through the light existence plane. Capturing an inspection image including a plurality of bright spots appearing on the plurality of flying objects, and c) a plurality of point spread functions respectively corresponding to a plurality of divided regions set in the inspection image And d) obtaining a corrected inspection image by correcting one or more bright points included in each divided region of the inspection image using a point spread function corresponding to each of the divided regions. And e) the corrected inspection image There and a step of determining the quality of the discharge operation of liquid from the plurality of discharge ports.

  In the present invention, the quality of the discharge operation can be determined with high accuracy.

It is a front view of the substrate processing apparatus concerning one embodiment. It is a top view of a substrate processing apparatus. It is a side view of a discharge head and a standby pod. It is a bottom view which shows the lower surface of a discharge head. It is a block diagram which shows the function of a control unit. It is a perspective view which shows an ejection head, a light emission part, and an imaging part. It is a figure which shows the flow of a test | inspection of discharge operation. It is a figure which shows a test | inspection image. It is a figure which shows a test | inspection image. It is a figure which shows the luminescent spot before correction | amendment. It is a figure which shows the luminescent spot after correction | amendment. It is a figure which shows a test | inspection image. It is a figure which shows a test | inspection image.

  FIG. 1 is a front view of a substrate processing apparatus 1 according to an embodiment of the present invention. FIG. 2A is a plan view of the substrate processing apparatus 1. In FIG. 2A, the orientation of the substrate processing apparatus 1 is changed from FIG. The substrate processing apparatus 1 is a single-wafer type apparatus that processes semiconductor substrates 9 (hereinafter simply referred to as “substrates 9”) one by one. In the substrate processing apparatus 1, a liquid is discharged to the substrate 9 to perform a predetermined process. In the present embodiment, a cleaning process for removing particles and the like from the substrate 9 is performed by discharging droplets of the processing liquid onto the substrate 9. In the substrate processing apparatus 1, for example, droplets having a diameter of about 20 μm are ejected toward the substrate 9 in a spray form.

  As shown in FIGS. 1 and 2A, the substrate processing apparatus 1 includes a substrate holding unit 21, a cup unit 22, a substrate rotating mechanism 23, a processing liquid supply unit 3, a supply unit moving mechanism 35, and a protective liquid supply. A unit 36, a standby pod 4, a discharge inspection unit 5, a chamber 6, and a control unit are provided. The chamber 6 includes the substrate holding unit 21, the cup unit 22, the substrate rotating mechanism 23, the processing liquid supply unit 3, the supply unit moving mechanism 35, the protective liquid supply unit 36, the standby pod 4, and the discharge inspection unit 5. 60. The chamber 6 is a light shielding chamber that blocks light from entering the internal space 60 from the outside. 1 and 2A, the chamber 6 is indicated by a broken line, and the inside of the chamber 6 is illustrated.

  The substrate holding unit 21 holds the substrate 9 in a state where one main surface 91 (hereinafter referred to as “upper surface 91”) of the substrate 9 is directed upward in the chamber 6. A fine pattern such as a circuit pattern is formed on the upper surface 91 of the substrate 9. The cup portion 22 is a substantially cylindrical member surrounding the substrate 9 and the substrate holding portion 21. The substrate rotation mechanism 23 is disposed below the substrate holding unit 21. The substrate rotation mechanism 23 rotates the substrate 9 together with the substrate holder 21 in a horizontal plane around a rotation axis that passes through the center of the substrate 9 and is perpendicular to the upper surface 91 of the substrate 9.

  The processing liquid supply unit 3 includes a discharge head 31 that discharges the processing liquid downward, and a processing liquid pipe 32 that supplies the processing liquid to the discharge head 31. The discharge head 31 is disposed above the substrate holding part 21 inside the cup part 22. In other words, the lower surface of the ejection head 31 is located between the upper opening 220 of the cup portion 22 and the upper surface 91 of the substrate 9. The discharge head 31 is a device that continuously discharges minute droplets separated from each other from a plurality of discharge ports described later. The processing liquid is discharged toward the upper surface 91 of the substrate 9 by the discharge head 31, whereby the above-described predetermined processing is performed on the substrate 9.

  As the treatment liquid (that is, the cleaning liquid), liquids such as pure water (preferably deionized water (DIW)), carbonated water, a mixed solution of ammonia water and hydrogen peroxide water are used. The design discharge direction of the processing liquid from the discharge head 31 is approximately parallel to the vertical direction (that is, the direction of gravity).

  FIG. 3 is a bottom view showing the lower surface 311 of the ejection head 31. The lower surface 311 of the discharge head 31 is provided with a plurality of discharge ports including four discharge port arrays 313a to 313d. Each of the discharge port arrays 313a to 313d has a plurality of discharge ports 314a to 314d arranged linearly in the left-right direction in FIG. 3 at a predetermined arrangement pitch. The diameter of each discharge port 314a-314d is about 5 micrometers-10 micrometers. In FIG. 3, each of the discharge ports 314a to 314d is drawn larger than the actual size, and the number of the discharge ports 314a to 314d is drawn smaller than the actual size. In the ejection head 31, minute droplets of the processing liquid are ejected from each of the plurality of ejection ports 314a to 314d.

  In the following description, the horizontal direction in FIG. Further, the discharge port arrays 313a to 313d arranged from the upper side to the lower side in FIG. 3 are respectively referred to as “first discharge port array 313a”, “second discharge port array 313b”, and “third discharge port array 313c”. And “fourth outlet row 313d”. Furthermore, the plurality of discharge ports 314a of the first discharge port row 313a are referred to as “first discharge ports 314a”, and the plurality of discharge ports 314b of the second discharge port row 313b are referred to as “second discharge ports 314b”. The plurality of discharge ports 314c of the third discharge port row 313c are referred to as “third discharge ports 314c”, and the plurality of discharge ports 314d of the fourth discharge port row 313d are referred to as “fourth discharge ports 314d”.

  The first discharge port row 313a, the second discharge port row 313b, the third discharge port row 313c, and the fourth discharge port row 313d are linear shapes extending in the above-described arrangement direction, and are arranged in parallel to each other. In the direction perpendicular to the arrangement direction (that is, the vertical direction in FIG. 3), the distance between the first discharge port array 313a and the second discharge port array 313b is the third discharge port array 313c and the fourth discharge port array. It is equal to the distance between 313d and smaller than the distance between the 2nd discharge port row | line | column 313b and the 3rd discharge port row | line | column 313c. The second discharge port array 313b is arranged so as to be shifted from the first discharge port array 313a by a predetermined shift distance on the right side in FIG. 3, which is one side in the arrangement direction. The fourth discharge port array 313d is arranged to be shifted from the third discharge port array 313c by the shift distance on the right side in FIG. The shift distance is a distance smaller than the above-described arrangement pitch, for example, a distance that is half of the arrangement pitch.

  In the ejection head 31, when viewed from a direction perpendicular to the arrangement direction and parallel to the lower surface 311 of the ejection head 31, the plurality of first ejection ports 314a and the plurality of second ejection ports 314b are alternately arranged in the arrangement direction. The plurality of third discharge ports 314c and the plurality of fourth discharge ports 314d are alternately arranged in the arrangement direction. In addition, the plurality of first discharge ports 314a and the plurality of third discharge ports 314c overlap each other, and the plurality of second discharge ports 314b and the plurality of fourth discharge ports 314d overlap each other.

  As shown in FIGS. 1 and 2A, the supply unit moving mechanism 35 includes an arm 351, a rotation shaft 352, a head rotation mechanism 353, and a head lifting mechanism 354. The arm 351 extends in the horizontal direction from the rotation shaft 352. A discharge head 31 is attached to the tip of the arm 351. The head rotation mechanism 353 rotates the ejection head 31 in the horizontal direction around the rotation shaft 352 together with the arm 351. The head lifting mechanism 354 moves the ejection head 31 in the vertical direction together with the arm 351. The head rotation mechanism 353 includes, for example, an electric motor. The head lifting mechanism 354 includes, for example, a ball screw mechanism and an electric motor.

  The protective liquid supply unit 36 is directly or indirectly fixed to the discharge head 31 and discharges the protective liquid obliquely downward. As the protective liquid, liquids such as pure water (preferably deionized water), carbonated water, a mixed solution of ammonia water and hydrogen peroxide water are used as in the case of the above-described treatment liquid. The protective liquid may be the same type of liquid as the treatment liquid or may be a different type of liquid. In the substrate processing apparatus 1, the protective liquid discharged in the form of a liquid column from the protective liquid supply unit 36 toward the upper surface 91 of the substrate 9 spreads on the substrate 9 below the discharge head 31, thereby directly below the discharge head 31. A protective liquid film (hereinafter referred to as “protective liquid film”) having a predetermined thickness is formed. The protective liquid supply unit 36 moves together with the ejection head 31 by the head rotation mechanism 353 and the head lifting mechanism 354.

  FIG. 4 is a block diagram showing functions of the control unit 7. In FIG. 4, the configuration other than the control unit 7 is also drawn. The control unit 7 includes a process control unit 71, an inspection control unit 72, and an inspection calculation unit 73. The processing of the substrate 9 is performed by controlling the substrate rotation mechanism 23, the processing liquid supply unit 3, the supply unit moving mechanism 35, the protective liquid supply unit 36, and the like by the processing control unit 71. The inspection control unit 72 controls the processing liquid supply unit 3, the supply unit moving mechanism 35, the discharge inspection unit 5, and the like, thereby inspecting the discharge operation of the processing liquid from the plurality of discharge ports 314a to 314d of the discharge head 31. Is done.

  The inspection calculation unit 73 is a part of the ejection inspection unit 5 and includes a determination unit 75 and a bright spot correction unit 76. The bright spot correction unit 76 includes a divided region setting unit 761, a function storage unit 762, an image correction unit 763, and a function acquisition unit 769. The determination unit 75 and the bright spot correction unit 76 are used for the above-described ejection operation inspection.

  When processing the substrate 9 in the substrate processing apparatus 1 shown in FIGS. 1 and 2A, first, the substrate 9 is carried into the chamber 6 and held by the substrate holding unit 21. When the substrate 9 is carried in, the ejection head 31 stands by at a standby position on the standby pod 4 provided outside the cup portion 22 as indicated by a two-dot chain line in FIG. 2A. FIG. 2B is an enlarged side view showing the ejection head 31 located at the standby position together with the standby pod 4. The standby pod 4 is a substantially rectangular parallelepiped container, and has an opening at the top. At the standby position, a part of the ejection head 31 is inserted into the standby pod 4 through the opening. In FIG. 2B, illustration of the protective liquid supply unit 36 is omitted. In addition, a discharge head 31 located at an inspection position described later is indicated by a two-dot chain line. When the substrate 9 is held by the substrate holding unit 21, the substrate rotation mechanism 23 is driven by the process control unit 71 and rotation of the substrate 9 is started.

  Subsequently, the head rotation mechanism 353 and the head elevating mechanism 354 are driven by the processing control unit 71, and the ejection head 31 and the protective liquid supply unit 36 are lifted from the standby position, moved downward above the cup unit 22, and then lowered. . As a result, the ejection head 31 and the protective liquid supply unit 36 move to the inside of the cup unit 22 and above the substrate holding unit 21 via the upper opening 220 of the cup unit 22. Next, supply of the protective liquid from the protective liquid supply unit 36 onto the substrate 9 is started, and a protective liquid film covering a part of the upper surface 91 of the substrate 9 is formed. In addition, the processing liquid is started to be ejected (that is, the ejection of minute droplets) from the plurality of ejection ports 314a to 314d of the ejection head 31 toward the upper surface 91 of the substrate 9 on which the protective liquid film is formed. The protective liquid film covers in advance a plurality of designed landing points (that is, landing points of microdroplets) on the substrate 9 of the processing liquid from the plurality of discharge ports 314a to 314d.

  A number of micro droplets ejected from the ejection head 31 toward the protective liquid film collide with the protective liquid film on the upper surface 91 of the substrate 9 and indirectly collide with the upper surface 91 of the substrate 9 through the protective liquid film. To do. Then, foreign matters such as particles adhering to the upper surface 91 of the substrate 9 are removed from the substrate 9 by the impact caused by the collision of the minute droplets of the processing liquid. In other words, the cleaning process of the upper surface 91 of the substrate 9 is performed by the kinetic energy indirectly applied to the substrate 9 through the protective liquid film by the fine droplets of the processing liquid.

  In this way, the microdroplets of the processing liquid collide with the substrate 9 through the protective liquid film, so that the microdroplets are formed on the upper surface 91 of the substrate 9 as compared with the case where the microdroplets directly collide with the substrate. The substrate 9 can be cleaned while preventing or suppressing damage to the pattern or the like. In addition, since the portion of the substrate 9 on which the cleaning process is performed is covered with the protective liquid, it is possible to prevent or suppress particles and the like removed from the substrate 9 from reattaching to the upper surface 91 of the substrate 9. it can.

  In the substrate processing apparatus 1, the ejection head 31 and the protection liquid supply unit 36 are rotated by the head rotation mechanism 353 in parallel with the discharge of the protection liquid and the processing liquid. The ejection head 31 and the protective liquid supply unit 36 repeat horizontal reciprocation between the upper part of the rotating substrate 9 and the upper part of the outer edge of the substrate 9. Thereby, the cleaning process is performed on the entire upper surface 91 of the substrate 9. The protective liquid and the processing liquid supplied to the upper surface 91 of the substrate 9 are scattered from the edge of the substrate 9 to the outside by the rotation of the substrate 9. The protective liquid and the processing liquid splashed from the substrate 9 are received by the cup portion 22 and discarded or collected.

  When the predetermined process (that is, the cleaning process of the substrate 9) with the processing liquid from the discharge head 31 is completed, the discharge of the protective liquid and the processing liquid is stopped. The ejection head 31 and the protective liquid supply unit 36 are raised above the upper opening 220 of the cup unit 22 by the head lifting mechanism 354, and are moved to the inspection position (see FIG. 2B) above the standby pod 4 by the head rotation mechanism 353. Moving. The inspection position is a position above the standby position described above. At the inspection position of the ejection head 31, the ejection inspection unit 5 inspects the processing liquid ejection operation from the plurality of ejection ports 314 a to 314 d of the ejection head 31 periodically or as necessary.

  FIG. 5 is a perspective view showing the ejection head 31 at the inspection position and the ejection inspection unit 5 arranged around the ejection head 31. The ejection inspection unit 5 is an ejection inspection apparatus that inspects the liquid ejection operation from the plurality of ejection ports 314 a to 314 d (see FIG. 3) of the ejection head 31. The discharge inspection unit 5 includes a light emitting unit 51 and an imaging unit 52. The light emitting unit 51 and the imaging unit 52 are disposed obliquely below the ejection head 31, avoiding directly below the ejection head 31. The light emission part 51 and the imaging part 52 are controlled by the inspection control part 72 of the control unit 7, as shown in FIG.

  The light emitting unit 51 illustrated in FIG. 5 includes a light source and an optical system that converts light from the light source into linear light extending in a substantially horizontal direction. As the light source, for example, a laser diode or an LED (light emitting diode) element is used. The light emitting unit 51 emits light toward the lower side of the ejection head 31 along a light existence surface that is a predetermined virtual surface. In FIG. 5, the optical axis J <b> 1 of the light emitting part 51 is drawn with a one-dot chain line, and the outline of the planar light emitted from the light emitting part 51 is indicated with a two-dot chain line denoted by reference numeral 510.

  The planar light 510 from the light emitting portion 51 passes directly under the ejection head 31 in the vicinity of the lower surface 311 of the ejection head 31. In the substrate processing apparatus 1, a predetermined drive signal is sent from the inspection control unit 72 to the processing liquid supply unit 3, and the processing liquid is discharged from the plurality of discharge ports 314 a to 314 d of the discharge head 31 toward the inside of the standby pod 4. The Then, when a plurality of flying bodies that are processing liquids discharged from the plurality of discharge ports 314 a to 314 d of the discharge head 31 pass through the above-described light existence surface (that is, pass through the planar light 510), Light is emitted from the emitting unit 51 to the plurality of flying objects. The planar light 510 is approximately perpendicular to the designed ejection direction of the processing liquid from the ejection head 31 (that is, a predetermined ejection direction determined in advance for a plurality of flying objects). Strictly speaking, the planar light 510 (that is, the light existing surface) is inclined by a slight angle (for example, 5 ° to 10 °) with respect to a plane perpendicular to the predetermined ejection direction of the plurality of flying objects. Preferably it is.

  The imaging unit 52 is disposed below the light existence surface with the imaging axis J2 facing the planar light 510 positioned below the ejection head 31. The imaging direction (that is, the direction in which the imaging axis J2 faces) in the imaging unit 52 is inclined with respect to a plane perpendicular to the predetermined ejection direction of the plurality of flying objects. As the imaging unit 52, for example, a charge-coupled device (CCD) camera is used. The imaging unit 52 acquires an inspection image including a plurality of bright spots appearing on the plurality of flying bodies by imaging the processing liquid (that is, a plurality of flying bodies) that passes through the planar light 510. In the ejection inspection unit 5, one frame of a still image is extracted as an inspection image from the imaging result obtained by the imaging unit 52. The imaging unit 52 is arranged at a position where the first discharge port array 313a is visible on the front side among the four discharge port arrays 313a to 313d in FIG.

  FIG. 6 is a diagram showing a flow of inspection of the discharge operation by the discharge inspection unit 5. In the discharge inspection unit 5, first, the planar light 510 is emitted from the above-described light emitting unit 51, and light is irradiated to a plurality of flying objects that are treatment liquids discharged from the plurality of discharge ports 314a to 314d (step). S11). Subsequently, the above-described inspection image is acquired by the imaging unit 52 (step S12).

  FIG. 7 is a diagram showing the inspection image 8. In the inspection image 8, a plurality of bright spots 81 respectively corresponding to the plurality of ejection ports 314a to 314d of the ejection head 31 are arranged in a direction corresponding to the arrangement direction of the ejection ports 314a to 314d. In the ejection inspection unit 5, since the planar light 510 has a slight thickness, each bright spot 81 has a substantially elliptical shape that is long in the direction corresponding to the vertical direction in the inspection image 8. Some of the plurality of bright spots 81 are located outside the in-focus range of the imaging unit 52, and other bright spots 81 are blurred (so-called out of focus) on the inspection image 8. Compared to, it spreads greatly or becomes a shape different from the actual shape.

  The output from the imaging unit 52 is sent to the inspection calculation unit 73 (see FIG. 4) of the control unit 7. In the inspection calculation unit 73, a binarization process is performed on the inspection image 8, and a plurality of bright spots 81 are extracted and background noise and the like are removed.

  Subsequently, as shown in FIG. 8, a plurality of divided regions 82 are set on the inspection image 8 by the divided region setting unit 761 (see FIG. 4) of the bright spot correcting unit 76 (step S13). The plurality of divided regions 82 are set to regions where a plurality of bright spots 81 exist in the inspection image 8. The plurality of divided regions 82 are arranged in a direction corresponding to the above-described arrangement direction on the inspection image 8. In the example shown in FIG. 8, twelve divided regions 82 are set on the inspection image 8. Specifically, the six divided regions 82 are arranged in the region where the bright spots 81 corresponding to the first discharge port row 313a and the second discharge port row 313b exist, and the other six divided regions 82 are the first They are arranged in a region where the bright spots 81 corresponding to the third discharge port array 313c and the fourth discharge port array 313d exist.

  Each divided region 82 has a substantially rectangular shape with a predetermined size. The shape and size of the plurality of divided regions 82 on the inspection image 8 are the same. In the example illustrated in FIG. 8, each divided region 82 is substantially square, and its four sides are parallel to the vertical direction or the horizontal direction of the inspection image 8. The plurality of divided regions 82 are arranged on the inspection image 8 without overlapping each other. Moreover, the outlines parallel to the vertical direction of the adjacent divided regions 82 overlap each other. Each divided region 82 of the inspection image 8 includes one or more bright spots 81. Further, each bright spot 81 on the inspection image 8 is included in one of the divided regions 82. Note that the shape and size of the plurality of divided regions 82 may be variously changed. For example, each divided area 82 may be rectangular.

  In the divided area 82 including two or more bright spots 81 among the plurality of divided areas 82, the distance between the two bright spots 81 having the largest distance in the imaging direction of the imaging unit 52 (that is, the direction in which the imaging axis J2 faces). Is less than or equal to the depth of field of the imaging unit 52. In other words, the size of the divided area 82 is such that the number of bright spots 81 included in the divided area 82 is one, or in the imaging direction between the plurality of bright spots 81 included in the divided area 82. The maximum distance is set to be equal to or smaller than the depth of field of the imaging unit 52.

  Next, a plurality of point spread functions (PSF) corresponding to the plurality of divided regions 82 are prepared by the function storage unit 762 (see FIG. 4) (step S14). The point spread function is a function corresponding to the defocus amount of each divided region 82 at the time of imaging. The point spread function corresponding to each divided region 82 is acquired, for example, prior to acquisition of the inspection image 8 and stored in the function storage unit 762 in advance. In the bright spot correction unit 76, the function storage unit 762 calls the point spread function corresponding to each divided region 82 and prepares it by sending it to the image correction unit 763 (see FIG. 4).

  Acquisition of the point spread function corresponding to each divided region 82 is performed using, for example, a reference image acquired by the imaging unit 52. The reference image is an image including a plurality of bright spots 81 when the treatment liquid discharge operations from the plurality of discharge ports 314a to 314d are all normal. In this case, a reference image is prepared in advance, and the divided region setting unit 761 sets the plurality of divided regions 82 in the reference image. Then, the function acquisition unit 769 acquires an image of one bright spot 81 included in each divided region 82 as a point spread function corresponding to each divided region 82. In other words, each point spread function is one bright spot 81 included in the divided region 82 corresponding to each point spread function when a plurality of divided regions 82 are set in the reference image.

  When the number of bright spots 81 included in the divided area 82 on the reference image is 1, the image of the one bright spot 81 becomes a point spread function of the divided area 82. When two or more bright spots 81 are included in the divided area 82 on the reference image, the point spread function of the divided area 82 including the two or more bright spots 81 is, for example, the two or more bright spots 81. Among these, the image of one bright spot 81 closest to the center of the divided area 82 is shown.

  Acquisition of the point spread function corresponding to each divided region 82 may be performed by other methods. For example, a plurality of point spread functions corresponding to the plurality of divided regions 82 may be acquired by imaging point light sources arranged at positions corresponding to the plurality of divided regions 82. Specifically, first, the bright spot reference position of the bright spot 81 included in each divided region 82 is obtained. The bright spot reference position is a point at which the discharge center line extending from each discharge port in the design discharge direction of the processing liquid intersects with the planar light 510 (that is, the above-described light existence surface). In other words, the bright spot reference position is the position of the bright spot 81 when the processing liquid is normally ejected from the ejection port.

  Subsequently, an inspection distance that is a distance between the starting point of the imaging axis J2 of the imaging unit 52 and the bright spot reference position is obtained. When the number of bright spots 81 included in the divided area 82 is one, the inspection distance of the one bright spot 81 is determined as a divided area distance that is a distance between the imaging unit 52 and the divided area 82. . When two or more bright spots 81 are included in the divided area 82, for example, the inspection distance of one bright spot 81 closest to the center of the divided area 82 is determined as the divided area distance. Alternatively, the inspection distances of two or more bright spots 81 included in the divided area 82 are obtained, and the average of these inspection distances is determined as the divided area distance.

  Then, a point light source (for example, a pinhole mirror or a very small LED is used) is disposed at a position separated from the imaging unit 52 by the divided region distance, and the point light source is imaged by the imaging unit 52. An image of the point light source imaged by the imaging unit 52 is acquired as a point spread function of the divided region 82.

  In acquiring the point spread function of the divided region 82 using the above-described point light source, the point light source does not necessarily have to be imaged by the imaging unit 52. For example, a point light source arranged at a position separated by a divided region distance is imaged by another imaging unit equivalent to the imaging unit 52 provided outside the substrate processing apparatus 1, and the image of the point light source is converted into a divided region. It may be acquired as a point spread function of the divided region 82 corresponding to the distance.

  Acquisition of the point spread function of the divided region 82 may be performed without performing imaging by the imaging unit. For example, the plurality of point spread functions corresponding to the plurality of divided regions 82 performs a ray tracing calculation on the light emitted from the point light source virtually arranged at the position corresponding to the plurality of divided regions 82. Is obtained by In other words, an image obtained when it is assumed that a point light source arranged at a position separated by the above-described divided region distance corresponding to each divided region 82 is imaged by the imaging unit 52 is obtained by simulation to obtain a point spread. Obtained as a function. The simulation is performed using, for example, optical design software ZEMAX (ZEMAX, Washington, USA) or codeV (synopsys, California, USA). The point spread function may be obtained by other simulation methods. Further, the point spread function may be acquired in another format such as a mathematical formula instead of an image.

  When the point spread function of each divided region 82 is prepared in step S14, the image correction unit 763 causes one or more bright spots 81 included in each divided region 82 of the inspection image 8 to correspond to each divided region 82. A corrected inspection image is acquired by performing correction using the point spread function (step S15). Specifically, the image correction unit 763 extracts one divided region 82 from the plurality of divided regions 82, and the point spread corresponding to the divided region 82 with respect to all the bright spots 81 included in the divided region 82. A deconvolution operation with the function is performed. Thereby, correction (so-called blur correction) of each bright spot 81 in the divided area 82 is performed, and a focused image of each bright spot 81 is estimated. The above deconvolution operation is performed using, for example, a Wiener filter. FIG. 9A is a diagram showing a bright spot 81 before correction in one divided region 82. FIG. 9B is a diagram showing the corrected bright spot 81 in the divided area 82. The above-described blur correction of each bright spot 81 may be performed by another known method using a point spread function.

  In the image correction unit 763, the same blur correction processing is performed for each of the plurality of divided regions 82. Thereby, in-focus images of all the bright spots 81 included in the inspection image 8 are estimated. In other words, the image correcting unit 763 performs image restoration processing for restoring a corrected inspection image that is a true image (that is, a focused image) from the inspection image 8 that is a partial blurred image including a non-focused region. Done. The corrected inspection image is a focused image in which all the bright spots 81 included in the inspection image 8 are approximately focused (that is, all the bright spots 81 are approximately in focus). Acquisition of the corrected inspection image is performed by, for example, GPU general-purpose computing (GPGPU).

  When the corrected inspection image is acquired, the determination unit 75 (see FIG. 4) determines the quality of the processing liquid discharge operation from the plurality of discharge ports 314a to 314d using the corrected inspection image (step S16). The quality determination of the discharge operation may be performed by various methods. For example, the pass / fail determination method described in JP 2014-179450 A may be applied to the corrected inspection image acquired in step S15. Specifically, a plurality of normal ejection determination frames respectively corresponding to the plurality of ejection ports 314a to 314d are set on the corrected inspection image. When the bright spot 81 is present in each normal discharge determination frame, it is determined that the discharge operation at the discharge port corresponding to each normal discharge determination frame is normal. When the bright spot 81 does not exist in each normal discharge determination frame, it is determined that the discharge operation at the discharge port corresponding to each normal discharge determination frame is abnormal. The occurrence of the discharge abnormality is notified from the determination unit 75 to the operator or the like through a notification unit 79 (see FIG. 4) such as a monitor of the discharge inspection unit 5. Then, maintenance of the ejection head 31 such as cleaning of the ejection ports 314a to 314d is performed before the processing for the substrate 9 scheduled thereafter is performed.

  The quality determination of the ejection operation in step S16 may be performed based on, for example, the intervals in the arrangement direction of the plurality of bright spots 81 on the corrected inspection image. Specifically, if the interval between the plurality of bright spots 81 is approximately equal to the predetermined interval, it is determined that the discharge operation at each of the discharge ports 314a to 314d is normal. On the other hand, when the interval between two adjacent bright spots 81 is twice or more the predetermined interval, it is determined that a non-ejection outlet exists between the two outlets corresponding to the two bright spots 81. . In addition, when there are two adjacent bright spots 81 whose distance is larger or smaller than a predetermined distance (or smaller), either one or both of the two discharge ports corresponding to the two bright spots 81 are slanted. It is determined that a discharge abnormality has occurred.

  The quality determination of the ejection operation in step S16 may be performed using, for example, the above-described reference image. Specifically, first, a plurality of divided regions 82 are set in the above-described reference image, and one or more bright spots 81 included in each divided region 82 are used using a point spread function corresponding to each divided region 82. As a result of the correction, a correction reference image is acquired. Then, the correction inspection image acquired in step S15 is compared with the correction reference image, and when the bright spot 81 corresponding to the bright spot 81 on the correction reference image does not exist on the correction inspection image, or correspondingly. When the position of the bright spot 81 is greatly shifted, it is determined that an abnormality has occurred in the discharge of the processing liquid from the discharge port corresponding to the bright spot 81 on the corrected inspection image.

  As described above, the ejection inspection unit 5 of the substrate processing apparatus 1 includes the light emitting unit 51, the imaging unit 52, the function storage unit 762, the image correction unit 763, and the determination unit 75. When the light emitting unit 51 emits light along a predetermined light existence surface, a plurality of flying bodies, which are liquids ejected from the plurality of ejection ports 314a to 314d, pass through the light existence surface. A plurality of flying objects are irradiated with light. The imaging unit 52 acquires a test image 8 including a plurality of bright spots 81 appearing on the plurality of flying bodies by imaging a plurality of flying bodies passing through the light existence plane. The function storage unit 762 stores a plurality of point spread functions respectively corresponding to the plurality of divided regions 82 set in the inspection image 8. The image correction unit 763 acquires a corrected inspection image by correcting one or more bright spots 81 included in each divided region 82 of the inspection image 8 using a point spread function corresponding to each divided region 82. The determination unit 75 determines the quality of the liquid discharge operation from the plurality of discharge ports 314a to 314d using the corrected inspection image.

  In the discharge inspection unit 5, the above-described steps S <b> 11 to S <b> 16 are performed, and all the bright spots 81 are corrected by correcting the blur of the bright spots 81 located outside the focusing range of the imaging unit 52 on the inspection image 8. A corrected inspection image that is an in-focus image that is approximately focused (that is, all the bright spots 81 are approximately in focus) is obtained. In the corrected inspection image, the actual shape of the bright spot 81 (that is, the shape of the flying object) is displayed with high accuracy. By performing the discharge inspection using the corrected inspection image, a plurality of discharge ports 314a to 314d. The quality of the discharge operation can be accurately determined.

  As described above, the shapes and sizes of the plurality of divided regions 82 are the same. Therefore, a plurality of divided regions 82 can be easily set on the inspection image 8. In addition, in the divided region 82 including two or more bright spots 81 among the plurality of divided areas 82, the distance between the two bright spots 81 having the largest distance in the imaging direction of the imaging unit 52 is the coverage of the imaging unit 52. Below the depth of field. Therefore, two or more bright spots 81 included in one divided region 82 have similar degrees of blur due to deviation from the in-focus range. For this reason, even when the same point spread function is applied to two or more bright spots 81 included in one divided region 82 when acquiring the corrected inspection image in step S15, the two or more bright spots are applied. 81 can be corrected appropriately (that is, with high accuracy).

  As shown in FIG. 8, since the plurality of divided regions 82 include divided regions 82 including two or more bright spots 81, the number of the plurality of divided areas 82 is the number of the plurality of bright spots 81. Less than. In this way, by reducing the number of the plurality of divided regions 82, setting of the divided regions 82 on the inspection image 8, acquisition of the point spread function of each divided region 82, and bright points 81 in each divided region 82 are obtained. Correction can be simplified. As a result, the inspection of the discharge operation of the discharge ports 314a to 314d by the discharge inspection unit 5 can be simplified. Further, the time required for the inspection of the ejection operation can be shortened.

  In the inspection image 8, the shape and size of the plurality of divided regions 82 are not necessarily the same. For example, as shown in FIG. 10, among the plurality of divided regions 82, the divided region 82 including the bright spot 81 closest to the in-focus position of the imaging unit 52 is set as the reference divided region 82 a, and the reference among the plurality of divided regions 82. The divided area 82a may be set to be the largest. In the example shown in FIG. 10, the size of the other regions excluding the reference divided region 82a among the plurality of divided regions 82 decreases as the distance from the reference divided region 82a increases. The number of bright spots 81 included in the divided areas 82 other than the reference divided area 82a is equal to or less than the number of bright spots 81 included in the reference divided area 82a.

  In the inspection image 8, the degree of blur of the bright spot 81 increases as the distance from the in-focus position of the imaging unit 52 increases. Therefore, when blur correction of a large number of bright spots 81 away from the in-focus position is performed with one point spread function, there is a possibility that bright spots 81 with reduced blur correction accuracy appear. Therefore, as described above, by reducing the size of the divided region 82 as the distance from the reference divided region 82a increases, blur correction of the bright spot 81 away from the in-focus position can be performed with high accuracy. .

  In the example illustrated in FIG. 10, in the same manner as described above, in the divided region 82 including two or more bright spots 81 among the plurality of divided areas 82, the distance between the two bright spots 81 having the largest distance in the imaging direction of the imaging unit 52. Is less than or equal to the depth of field of the imaging unit 52. For this reason, even when the same point spread function is applied to two or more bright spots 81 included in one divided region 82 when acquiring the corrected inspection image in step S15, the two or more bright spots are applied. 81 can be corrected appropriately (that is, with high accuracy). In the example illustrated in FIG. 10, in the plurality of divided regions 82, the reference divided region 82 a is approximately square, and the other divided regions 82 are approximately square or approximately rectangular. The shapes and sizes of the reference divided region 82a and the divided region 82 may be changed as appropriate.

  FIG. 11 is a diagram illustrating another example of the plurality of divided regions 82 set in the inspection image 8. In the example shown in FIG. 11, each of the plurality of divided regions 82 set on the inspection image 8 includes only one bright spot 81. That is, the number of the plurality of divided regions 82 is equal to the number of bright spots 81 on the inspection image 8. Thus, when acquiring the corrected inspection image in step S15, the blur correction of each bright spot 81 can be performed by applying the point spread function most suitable for each bright spot 81 on the inspection image 8. As a result, each bright spot 81 can be corrected appropriately (that is, with high accuracy).

  In the example shown in FIG. 11, each of the plurality of divided regions 82 is substantially square. The shapes and sizes of the plurality of divided regions 82 are the same, but may be changed as appropriate. For example, as in the example shown in FIG. 10, among the plurality of divided regions 82, the reference divided region 82 a including the bright spot 81 closest to the in-focus position of the imaging unit 52 is the largest, and other than the reference divided region 82 a. The size of the area may be reduced as the distance from the reference divided area 82a increases.

  As described above, in the ejection inspection unit 5, the acquisition of a plurality of point spread functions respectively corresponding to the plurality of divided regions 82 is performed using, for example, a reference image. Specifically, a reference image including a plurality of bright spots 81 in the case where the treatment liquid discharge operations from the plurality of discharge ports 314a to 314d are all normal is prepared in advance, and a plurality of point spread functions are included in the reference image. This is an image of one bright spot 81 included in the divided area 82 corresponding to each point spread function when the divided area 82 is set. Thereby, the point spread function corresponding to each divided region 82 can be easily obtained.

  Further, when a plurality of divided areas 82 are set in the reference image, the point spread function of the divided area 82 including two or more bright spots 81 is the center of the divided area 82 among the two or more bright spots 81. It is an image of one bright spot 81 closest to. In other words, in the divided region 82 including two or more bright spots 81, the distance in the imaging direction between the two or more bright spots 81 and the imaging unit 52 seems to be the most average ( That is, the image of the bright spot 81 (which is most likely to be the median of the distance) is used as the point spread function of the divided area 82. Thus, even when the same point spread function is applied to two or more bright spots 81 included in the divided region 82 when acquiring the corrected inspection image in step S15, the two or more bright spots 81 are applied. Can be appropriately corrected (that is, with high accuracy).

  The plurality of point spread functions may be acquired by, for example, imaging a point light source arranged at a position corresponding to the plurality of divided regions 82. Also in this case, the point spread function corresponding to each divided region 82 can be easily obtained. When the imaging of the point light source is performed by the imaging unit 52 of the ejection inspection unit 5, it is possible to acquire a point spread function that takes into account the influence of mechanical characteristics and the like unique to the imaging unit 52. As a result, the bright spot 81 can be corrected with higher accuracy when the corrected inspection image is acquired in step S15. On the other hand, when imaging of the point light source is performed by another imaging unit equivalent to the imaging unit 52 provided outside the substrate processing apparatus 1, the imaging unit of the discharge inspection unit 5 is used when installing the point light source. Since there is no arrangement restriction by a configuration other than 52 (for example, the light emitting unit 51), the point spread function corresponding to each divided region 82 can be obtained more easily.

  The plurality of point spread functions may be acquired, for example, by performing a ray tracing calculation on light emitted from a point light source virtually arranged at a position corresponding to the plurality of divided regions 82. Also in this case, the point spread function corresponding to each divided region 82 can be easily obtained.

  Various changes can be made in the substrate processing apparatus 1.

  For example, in the divided region 82 including two or more bright spots 81, the distance between the two bright spots 81 having the largest distance in the imaging direction of the imaging unit 52 is necessarily not more than the depth of field of the imaging unit 52. However, it may be larger than the depth of field.

  Two adjacent divided regions 82 may be separated from each other. Alternatively, two adjacent divided regions 82 may partially overlap. When the bright spot 81 is located in the overlapping region of the plurality of divided regions 82, for example, when acquiring the corrected inspection image in step S15, a plurality of point spread functions corresponding to the plurality of divided regions 82 including the overlapping region. And the bright spot 81 of the inspection image 8 may be corrected using the average of the point spread function.

  In the above description, non-ejection and oblique ejection are determined as ejection abnormalities at the ejection ports 314a to 314d, but other ejection operations may also be determined as ejection abnormalities. For example, the droplets ejected from the ejection head 31 may break up during flight and become a plurality of extremely small droplets. Such a very small droplet cannot give sufficient kinetic energy to the upper surface 91 of the substrate 9, and the substrate 9 may not be cleaned properly. Therefore, the discharge of such a small droplet may also be determined as a discharge abnormality of the discharge port.

  In the light emission part 51, it is not always necessary to emit light in a planar shape. Light extending linearly forward from the light emission part 51 is emitted along the light existence surface, and the light is emitted along the light existence surface. You may scan by optical scanning means, such as a polygon mirror. Accordingly, when the plurality of flying bodies that are the processing liquids discharged from the plurality of discharge ports 314a to 314d pass through the light existence surface, the plurality of flying bodies are irradiated with light. The light existence surface may be perpendicular to the designed ejection direction of the processing liquid from the ejection head 31, and the imaging direction in the imaging unit 52 is parallel to a plane perpendicular to the designed ejection direction. May be.

  The light emitting unit 51 and the imaging unit 52 may be disposed at a position other than the diagonally lower side of the ejection head 31, for example, the diagonally upper side of the ejection head 31. The discharge inspection unit 5 may be disposed at a position other than the vicinity of the standby position of the discharge head 31 (that is, the vicinity of the standby pod 4). For example, the light emitting unit 51 and the imaging unit 52 may be disposed obliquely above the ejection head 31 located on the substrate 9.

  The treatment liquid ejected from the ejection head 31 is not necessarily limited to a droplet shape, and a treatment liquid continuous in a liquid column shape may be ejected from the ejection head 31.

  The substrate processing apparatus 1 may be used for various processes other than the cleaning of the substrate 9. Moreover, in the substrate processing apparatus 1, you may utilize for the process of the glass substrate used for display apparatuses other than a semiconductor substrate, such as a liquid crystal display device, a plasma display, and FED (field emission display). Alternatively, the substrate processing apparatus 1 may be used for processing of an optical disk substrate, a magnetic disk substrate, a magneto-optical disk substrate, a photomask substrate, a ceramic substrate, a solar cell substrate, and the like.

  The apparatus including the light emitting unit 51, the imaging unit 52, the function storage unit 762, the image correction unit 763, and the determination unit 75 may be used as a discharge inspection apparatus that is independent from other configurations of the substrate processing apparatus 1. For example, in the apparatus for discharging liquid from a plurality of discharge ports to the above-described various substrates, the discharge inspection apparatus is used for inspecting a liquid discharge operation from the plurality of discharge ports.

  The configurations in the above-described embodiments and modifications may be combined as appropriate as long as they do not contradict each other.

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 5 Discharge inspection part 8 Inspection image 9 Substrate 21 Substrate holding part 31 Discharge head 51 Light emission part 52 Imaging part 75 Judgment part 81 Bright spot 82 Divided area 82a Reference divided area 314a-314d Discharge port 510 Planar light 762 Function storage unit 763 Image correction unit S11 to S16 Steps

Claims (11)

A discharge inspection device for inspecting the discharge operation of liquid from a plurality of discharge ports,
By emitting light along a predetermined light existence plane, when the plurality of flying bodies, which are liquids ejected from the plurality of ejection openings, pass through the light existence plane, light is emitted to the plurality of flying bodies. A light emitting portion to irradiate;
An imaging unit for acquiring an inspection image including a plurality of bright spots appearing on the plurality of flying objects by imaging the plurality of flying objects passing through the light existence surface;
A function storage unit that stores a plurality of point spread functions respectively corresponding to a plurality of divided regions set in the inspection image;
An image correction unit that obtains a corrected inspection image by correcting one or more bright points included in each divided region of the inspection image using a point spread function corresponding to each of the divided regions;
A determination unit that determines the quality of the liquid ejection operation from the plurality of ejection ports using the corrected inspection image;
A discharge inspection apparatus comprising: The discharge inspection apparatus according to claim 1,
A discharge inspection apparatus, wherein the plurality of divided regions have the same shape and size. The discharge inspection apparatus according to claim 1,
Of the plurality of divided areas, a divided area including the bright spot closest to the in-focus position of the imaging unit is set as a reference divided area, and the reference divided area is the largest of the plurality of divided areas and excludes the reference divided area. The discharge inspection apparatus according to claim 1, wherein the size of the other region decreases as the distance from the reference division region increases. The discharge inspection apparatus according to any one of claims 1 to 3,
In a divided region including two or more bright spots among the plurality of divided regions, a distance between two bright spots having the largest distance in the imaging direction of the imaging unit is equal to or smaller than a depth of field of the imaging unit. A discharge inspection apparatus characterized by that. The discharge inspection apparatus according to any one of claims 1 to 3,
The discharge inspection apparatus, wherein each of the plurality of divided regions includes only one bright spot. A discharge inspection apparatus according to any one of claims 1 to 5,
A reference image including the plurality of bright spots in a case where the liquid ejection operations from the plurality of ejection ports are all normal is prepared in advance,
An ejection inspection apparatus, wherein each point spread function is an image of one bright spot included in a divided region corresponding to each point spread function when the plurality of divided regions are set in the reference image. The discharge inspection apparatus according to claim 6,
When the plurality of divided areas are set in the reference image, the point spread function of the divided area including two or more bright spots is one of the two or more bright spots closest to the center of the divided area. An ejection inspection apparatus characterized by being an image of a bright spot. A discharge inspection apparatus according to any one of claims 1 to 5,
The discharge inspection apparatus, wherein the plurality of point spread functions are acquired by imaging a point light source disposed at a position corresponding to the plurality of divided regions. A discharge inspection apparatus according to any one of claims 1 to 5,
The plurality of point spread functions are obtained by performing a ray tracing operation on light emitted from a point light source virtually arranged at a position corresponding to the plurality of divided regions. Inspection device. A substrate processing apparatus,
A substrate holder for holding the substrate;
A discharge head that discharges liquid from a plurality of discharge ports toward the substrate and performs a predetermined process on the substrate;
The ejection inspection apparatus according to claim 1, wherein the ejection operation of the liquid from the plurality of ejection ports of the ejection head is inspected.
A substrate processing apparatus comprising: A discharge inspection method for inspecting a liquid discharge operation from a plurality of discharge ports,
a) By emitting light along a predetermined light existence plane, a plurality of flying bodies, which are liquids discharged from a plurality of ejection openings, pass through the plurality of flying bodies when passing through the light existence plane. Irradiating with light;
b) obtaining an inspection image including a plurality of bright spots appearing on the plurality of flying bodies by imaging the plurality of flying bodies passing through the light existence surface;
c) preparing a plurality of point spread functions respectively corresponding to a plurality of divided regions set in the inspection image;
d) obtaining a corrected inspection image by correcting one or more bright points included in each divided region of the inspection image using a point spread function corresponding to each of the divided regions;
e) determining the quality of the liquid ejection operation from the plurality of ejection ports using the corrected inspection image;
A discharge inspection method comprising: