JP5075458B2 - Surface inspection device - Google Patents

Description

  The present invention relates to a surface inspection apparatus that is used in an inspection process in semiconductor manufacturing and inspects for the presence or absence of foreign matter such as particles adhering to a wafer surface.

  A semiconductor device such as a CPU is manufactured by forming a fine pattern on the surface of a substrate such as a silicon wafer by performing surface treatment such as generation of a thin film and etching. Processing in the manufacturing process of a semiconductor device is very fine, and if particles adhere to the substrate surface, there is a problem such as circuit cutting, resulting in a decrease in quality and a decrease in yield.

  Therefore, as one of the semiconductor manufacturing processes, surface inspection for inspecting the number of particles attached to the substrate surface or the state of attachment is incorporated.

  As a method for detecting fine particles and scratches on the substrate surface, the substrate surface is irradiated with light such as a laser beam, scattered light from the particles and scratches is received, and the number of particles, scratches, etc. It is detected from the light receiving state. Further, in performing the surface inspection, in order to increase the reliability of the surface inspection accuracy, the particle detection result is calibrated for each surface inspection of the substrate or for every predetermined number of substrate inspections.

  The calibration of the detection result is performed by performing a surface inspection using a calibration wafer in which the particle size, number, and particle distribution state of the adhered particles are known, and the surface detection result of the calibration wafer performed by the surface inspection apparatus and calibration. And the known particle information of the wafer for inspection, and the inspection accuracy and inspection state of the surface inspection apparatus are calibrated so that the detection result of the surface inspection matches the information of the particle of the calibration wafer.

  In general, each time a surface inspection is performed, a calibration wafer is carried in from the outside of the surface inspection apparatus, set in the surface inspection apparatus, and unloaded from the surface inspection apparatus when the surface inspection is executed. Also, since the calibration wafer is a standard for surface inspection, the calibration wafer itself must be avoided from being contaminated by particles, etc., and must be stored in a clean atmosphere. The surface inspection by was inefficient and cumbersome storage management.

  Therefore, as shown in Patent Document 1, the present applicant stores a calibration wafer in the surface inspection apparatus, and carries the calibration wafer into and out of the surface inspection unit by a transfer robot of the surface inspection apparatus. Improved workability. In addition, by keeping the inside of the apparatus in a clean atmosphere, contamination of the calibration wafer is prevented.

  With the recent increase in the density of semiconductor devices, the presence of finer particles and the presence of scratches are factors that reduce product quality and yield. For this reason, even in the surface inspection apparatus, higher accuracy of inspection is required.

JP 2003-130809 A

  In view of such a situation, the present invention highly prevents contamination of the calibration wafer in the surface inspection apparatus, improves the calibration accuracy of the inspection result and the reliability of the calibration, and further improves the inspection accuracy of the surface inspection apparatus. It is intended to improve and improve reliability.

The present invention provides a surface inspection apparatus comprising: an inspection unit that inspects foreign matter and scratches on a substrate surface; and a conveyance unit that carries a substrate to be inspected and a calibration substrate into and out of the inspection unit. Comprises a calibration substrate storage unit for storing a plurality of calibration substrates, the calibration substrate storage unit being a container opened in the transport unit, and provided with a clean gas discharge nozzle so as to cross the upper part of the opening, Clean gas is discharged from the clean gas discharge nozzle, the clean gas flows toward the back of the storage unit along the stored substrate surface, flows back at the back wall surface, and a clean flow that flows out from the lower part of the opening is formed, the clean gas discharged from the clean gas discharge nozzle impinges on the surface of the calibration substrate of the upper, partly flow back relates to the construction surface inspection apparatus so as to flow out the apertures or al, the substrate An inspection section for inspecting foreign objects and scratches on the surface; In a surface inspection apparatus comprising an inspection unit having a substrate to be inspected and a conveyance unit for carrying in and out a calibration substrate, the conveyance unit includes a calibration substrate storage unit for storing a calibration substrate, and the calibration The substrate storage unit is a container having an opening in the transport unit, a lid that opens and closes the opening, and at least one substrate mounting plate, and a clean gas discharge nozzle is provided so as to cross the upper part of the opening. Clean gas is discharged from the clean gas discharge nozzle, the clean gas flows toward the back of the storage part along the surface of the stored substrate, and a clean flow that turns back on the back wall surface is formed, and the lid is in the closed state. A part of the opening relates to a surface inspection apparatus configured to maintain a clean flow inside the calibration substrate storage unit, and a part of the clean gas discharged from the clean gas discharge nozzle is Backflow and outflow from the opening In addition, a clean air flow is formed inside the transport unit, and the clean gas discharged from the clean gas discharge nozzle is supplied independently of the clean air flow. The calibration substrate storage unit includes a lid that opens and closes the opening, and the lid is related to a surface inspection apparatus configured to be closed when the cleanliness inside the transport unit is reduced. The lid relates to a surface inspection apparatus in which a part of the opening is opened so that a clean flow is maintained inside the calibration substrate storage portion in a closed state, and the calibration substrate storage portion is The substrate detector for detecting the presence or absence of a substrate, and in the state of detecting the substrate by the substrate detector, relates to a surface inspection apparatus that maintains the clean flow, and further, the calibration substrate storage unit, Teaching to set the board storage position The present invention relates to a surface inspection apparatus including a viewing window.

  According to the present invention, there is provided a surface inspection apparatus comprising an inspection unit for inspecting foreign matter and scratches on a substrate surface, and a transport unit for loading and unloading a substrate to be inspected and a calibration substrate in the inspection unit. Since the transport unit includes a calibration substrate storage unit for storing the calibration substrate, and the calibration substrate storage unit is configured so that a clean flow is formed therein, the calibration substrate is contaminated with foreign substances such as particles. Therefore, the reliability and accuracy of the calibration accuracy of the surface inspection are improved, and the reliability and accuracy of the accuracy of the surface inspection are improved.

  According to the invention, the calibration substrate storage unit is a container opened in the transport unit, and a clean gas discharge nozzle is provided so as to cross the upper part of the opening, and clean gas is discharged from the clean gas discharge nozzle. The clean gas flows along the surface of the stored substrate toward the back of the storage portion and forms a clean flow that flows back on the back wall surface, so that the calibration substrate is contaminated with foreign substances such as particles. Therefore, the reliability and accuracy of the calibration accuracy of the surface inspection are improved, and the reliability and accuracy of the accuracy of the surface inspection are improved.

  Further, according to the present invention, a part of the clean gas discharged from the clean gas discharge nozzle flows backward and flows out from the opening, so that intrusion of air from the outside is prevented, and the calibration wafer storage unit A decrease in internal cleanliness is prevented.

  According to the present invention, a clean air flow is formed inside the transport unit, and the clean gas discharged from the clean gas discharge nozzle is supplied independently of the clean air flow. Even when the air flow is stopped or the cleanliness is lowered, the inside of the calibration wafer storage unit can be kept highly clean.

  According to the present invention, the calibration substrate storage unit includes a lid that opens and closes the opening, and the lid is configured to be closed when the cleanliness inside the transport unit is reduced. The atmosphere does not enter the calibration wafer storage section, and the calibration wafer storage section can be kept highly clean.

  According to the present invention, the opening is partially opened so that a clean flow is maintained inside the calibration substrate storage portion when the lid is closed. Can be maintained while maintaining the clean flow, and the cleanliness inside the calibration wafer storage can be maintained.

  Further, according to the present invention, the calibration substrate storage unit includes a substrate detector that detects the presence or absence of a substrate, and maintains the clean flow in a state where the substrate is detected by the substrate detector. Even when there is an abnormality in the surface inspection apparatus, the cleanliness in the calibration wafer storage unit can be maintained, and contamination of the calibration wafer from foreign matter can be prevented.

  Furthermore, according to the present invention, since the calibration substrate storage section includes a teaching viewing window for setting the substrate storage position, excellent effects such as facilitating teaching work related to the loading and unloading of the calibration substrate are facilitated. Demonstrate.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  First, an outline of a surface inspection apparatus in which the present invention is implemented will be described with reference to FIGS.

  The surface inspection apparatus includes a transfer unit 1 including a wafer transfer robot and an inspection unit 2 connected to the transfer unit 1 and including a surface inspection unit.

  The transport unit 1 is provided with a cassette transfer stage 3 on the front surface, a cassette loading / unloading port 4 is provided at a position adjacent to the cassette transfer stage 3, and the cassette loading / unloading port 4 is opened and closed by an opening / closing door. . A calibration wafer storage unit 5 is provided on the upper rear surface of the transfer unit 1. The inspection unit 2 has an operation unit 6 on the front surface, and a display unit 7 on the upper front surface. A clean unit 9 is provided above the transport unit 1 and the inspection unit 2.

  The surface inspection unit 8 provided in the inspection unit 2 will be described with reference to FIG.

  The inside of the inspection unit 2 is divided into upper and lower parts, and the upper part is maintained in a clean atmosphere by clean air discharged from the clean unit 9, and the surface inspection part 8 is housed in a lower part located downstream of the clean air. Contains a control unit, a power supply unit, and the like.

  The surface inspection unit 8 includes an inspection table 12 on which a wafer 11 is placed, a motor 13 that rotates the inspection table 12 at a high speed, a laser light source 14 that emits an inspection laser beam, and a projection that irradiates the surface of the wafer 11 with a laser beam. Optical part 15, light receiving part 17 which receives the reflected light of the laser beam directly reflected on the surface of the wafer 11, converts the light receiving state into an electrical signal and inputs it to the computer 16, particles on the surface of the wafer 11, scratches, etc. A light receiving sensor 18 for detecting the reflected scattered light, a signal processing unit 19 for amplifying a light receiving signal from the light receiving sensor 18, performing necessary signal processing such as A / D conversion, and outputting the signal to the computer 16; The computer 16 controls the light emission state of the laser light source 14 based on the signal from the light receiving unit 17, and based on the signal from the signal processing unit 19. Calculates the Suto of particles adhering to the serial wafer 11.

  The calculation result in the computer 16, that is, the surface inspection result is output to the printer 21 and the display unit 7. Further, an inspection start command or inspection conditions are input from the operation unit 6.

  The computer 16 has a built-in surface inspection program and a program such as a sequence program for driving and controlling a transfer robot (described later) of the transfer unit 1, and carries the wafer 11 into and out of the transfer unit 1. Control signal is issued. In addition, the surface inspection program compares the inspection result of the target wafer with the inspection result of the product wafer and the inspection result of the calibration wafer, and calibrates the inspection result of the product wafer. A calibration program is included.

  The calibration program automatically operates according to a predetermined condition. For example, the operating condition includes a change in the type of the wafer 11 to be inspected, an elapsed time when the surface inspection is executed, and the number of surface inspections. The usage time of the laser light source 14 and the change in the contamination level in the apparatus can be mentioned. Further, it can be arbitrarily operated according to the will of the operator.

  The conveyance unit 1 will be described with reference to FIG.

  A cassette (not shown) loaded with the wafer 11 is transported and placed on the cassette transfer stage 3 (see FIG. 1).

  The transport unit 1 includes a frame 23 and a sealed or substantially sealed casing 24 configured by a panel (not shown) provided on the frame 23, and a clean unit 25 is disposed above the casing 24. A transfer space 26 is provided inside the housing 24 and below the clean unit 25, and a transfer robot 27 is accommodated in the transfer space 26.

  Below the transfer space 26 is a storage unit 28, which includes a drive unit 29, a control unit 31 for a transfer unit composed of a CPU and the like, an accessory device 32 including a power source, an electromagnetic valve, and the like. It is stored.

  The clean unit 25 sends purified air downward, and a clean air flow 30 is formed in the transfer space 26 from above to below.

  The transfer robot 27 has an elevating part 33 and two sets of arms 34 and 35 provided at the upper end of the elevating part 33. The arms 34 and 35 can be bent and extended independently. Wafer receiving plates 36 and 36 are provided at the tips of the arms 34 and 35, respectively.

  The arms 34 and 35 have a multi-node arm structure, and the wafer receiving plates 36 and 36 are independently advanced and retracted by bending and stretching of the arms 34 and 35, and the arms 34 and 35 are independent. The arms 34 and 35 are driven by the drive unit 29 and controlled by the control unit 31.

  The calibration wafer storage unit 5 is attached to the frame 23 so as to be positioned above the transfer space 26. The calibration wafer storage unit 5 has a hollow structure and opens at the top of the transfer space 26, and the opening is located within the operation range of the transfer robot 27. Further, the calibration wafer storage unit 5 protrudes horizontally so as not to obstruct the flow of clean air.

  Although the transfer robot 27 generates dust by a transfer operation, the calibration wafer storage unit 5 is located upstream of the transfer robot 27 by disposing the calibration wafer storage unit 5 above the transfer robot 27. Particles generated by the transfer robot 27 do not reach the calibration wafer storage unit 5.

  The calibration wafer storage unit 5 has at least one stage, and two upper and lower stages in the drawing, and a calibration wafer 37 is placed on the wafer placement board 38.

  The calibration wafer storage 5 is provided with a clean flow forming means 39, and the clean flow forming means 39 forms a clean flow 41 (described later) that flows in one direction along the surface of the calibration wafer 37. It has become. The clean flow forming means 39 forms a clean flow 41 inside the calibration wafer storage unit 5 so that the clean air flow 30 flows down without entering the calibration wafer storage unit 5, and A higher clean atmosphere is formed in the wafer storage unit 5 than in the transfer space 26.

  Particles with a known particle diameter and a known distribution density are attached to the calibration wafer 37, and the surface inspection result can be calibrated based on the signal surface-inspected by the calibration wafer 37. Yes. Further, when a plurality of calibration wafers 37 are stored in the calibration wafer storage unit 5, the particle diameter and distribution of the particles are different for each calibration wafer 37, so that various calibration conditions can be obtained. It has become.

  As described above, since a flow of clean air that does not stay is formed in the calibration wafer storage unit 5, that is, around the calibration wafer 37 that is stored, there are few particles in the clean air. Even if it is included, the particles do not adhere to the calibration wafer 37, and the surface of the calibration wafer 37 is always kept clean.

  Next, the calibration wafer storage unit 5 will be described with reference to FIGS.

  A wafer storage box 42 is attached to the housing 24 via a bracket 43. The wafer storage box 42 is a flat box-shaped container, one end of which protrudes into the transfer space 26, and the input end has an opening 44 that opens toward the transfer space 26. A door shaft 46 is rotatably provided above the entry end via a bearing 45, and a lid 47 is attached to the door shaft 46, and the lid 47 can close the opening 44.

  An actuator for rotating the lid 47 via the door shaft 46, for example, a rotary solenoid 48, is attached to one end of the door shaft 46, and the lid 47 is opened or closed, that is, the door shaft 46 is rotated at the other end. A lid opening / closing detector 49 for detecting a corner is attached.

  The lid 47 is rotated through the door shaft 46 by the operation of the rotary solenoid 48, the opening 44 is opened and closed by the lid 47, and the open / closed state is detected by the lid open / close detector 49. Further, it is preferable that the rotary solenoid 48 can be driven in a two-stage operation that can be in a half-open state or a fully-closed state. The open state of the lid 47 detected by the lid open / close detector 49 is sent to the control unit 31.

  A wafer pedestal 51 is installed inside the wafer storage box 42. In the wafer mounting table 51, the wafer mounting plates 38, 38 are supported in four stages by four columns 52, so that the wafer mounting plate 38 does not interfere with the wafer transfer operation by the wafer receiving plate 36. It has a concave shape.

  On the upper surface of the wafer mounting plate 38, receiving pieces 53 are provided at four places, and the calibration wafer 37 is placed on the receiving piece 53 while being supported at four places. The wafer receiving surface 53a of the receiving piece 53 is one step lower, and an inclined surface 53b is formed from the upper surface to the wafer receiving surface 53a, and the wafer is placed on the receiving piece 53 by the inclined surface 53b. Has become easier. The receiving piece 53 is made of a material that does not contaminate the calibration wafer 37, for example, polyacetal resin, polyimide resin, ceramic, or the like. This is to prevent metal contamination on the front and back surfaces of the wafer.

  A wafer detector 54 is provided at a required position on the upper surface of the wafer mounting plate 38, for example, in the vicinity of the receiving piece 53. The wafer detector 54 is a non-contact detector such as an optical sensor or an ultrasonic sensor. It detects the presence or absence of a wafer. The wafer detection result is sent to the control unit 31.

  A clean gas discharge nozzle 55 is provided along the upper end of the opening 44 and the upper surface of the wafer storage box 42, and the clean gas discharge nozzle 55 is connected to a clean gas supply source (not shown) via a clean gas supply system 57. Yes. In the clean gas discharge nozzle 55, gas discharge holes 56 are formed at a required pitch in a hollow tube horizontally traversing the opening 44, and the gas discharge holes 56 can be seen in FIG. Further, it is drilled horizontally or substantially horizontally, and the clean gas is discharged horizontally toward the back of the wafer storage box 42. The number, pitch, and hole diameter of the gas discharge holes 56 are selected so that the clean gas to be discharged has a uniform velocity distribution or a substantially uniform velocity distribution.

  As an example of the clean gas supply source, it is composed of a pneumatic feeding means such as a pump, a flow rate controller, a multi-stage filter with a progressively smaller scale, etc., which can remove and supply particles sufficiently, or a gas Examples of the supply source include those capable of supplying an inert gas such as nitrogen gas.

  Thus, the clean gas forming nozzle 39, the clean gas supply system 57, the clean gas supply source, and the like constitute the clean flow forming means 39, and the clean flow forming means 39 supplies the clean gas to the wafer storage box 42. A clean flow is formed inside the wafer storage box 42. On / off of the clean gas supply from the clean flow forming means 39 and the clean gas supply amount are controlled by the control unit 31.

  A viewing window 58 for teaching is provided on the upper surface of the wafer storage box 42, and a viewing window 59 for teaching is provided on the rear wall surface 42 a protruding to the outside, and the wafer storage box 42 is passed through the viewing windows 58 and 59. The inside can be observed and the viewing windows 58 and 59 are sealed. The viewing windows 58 and 59 allow the calibration robot 37 to be placed on the receiving piece 53 when the calibration robot 37 is conveyed by the conveyance robot 27. This is used when setting the receiving position.

  Hereinafter, the operation of the surface inspection apparatus will be described.

  First, the conveyance process of the calibration wafer 37 will be described.

  A cassette (not shown) for storing the calibration wafer 37 is placed on the cassette transfer stage 3. One or a plurality of calibration wafers 37 are stored in the cassette. When a plurality of calibration wafers 37 are accommodated, the calibration wafers 37 having different particle diameters, number of particles, or distribution density are used.

  The lid 47 is rotated upward by the rotary solenoid 48 via the door shaft 46 and the opening 44 is opened.

  With the lid 47 completely released, the transfer robot 27 moves the arms 34, 35 up and down, rotates, and moves back and forth from the cassette on the cassette transfer stage 3 to the calibration wafer storage unit 5. The calibration wafer 37 is transferred to the wafer mounting plate 38 at each stage of the wafer mounting table 51 and mounted on the wafer mounting plate 38 via the receiving piece 53.

  As shown in FIG. 9A, clean gas is discharged from the gas discharge hole 56 of the clean gas discharge nozzle 55 in the horizontal direction. The clean gas flows horizontally, reverses at the back wall surface 42a, splits into two upper and lower stages, flows along the surface of the calibration wafer 37, and merges with the clean air flow 30 from the opening 44 and below. To flow down. Accordingly, a clean flow 41 flowing along the surface of the calibration wafer 37 that does not stay in the wafer storage box 42 is formed, and the surface of the calibration wafer 37 is maintained in a clean state.

  When the calibration wafer 37 is stored in the calibration wafer storage unit 5, the detection unit (the light receiving sensor 18 and the signal processing unit 19) is calibrated as a pre-process in which the surface inspection of the product wafer 11 is performed. Is called.

  The calibration wafer 37 used in the calibration process is suitable for the wafer 11 to be inspected, for example, the film quality is the same, the particle diameter to be inspected, the number of particles, or the distribution density. Those that match the conditions are selected.

  The calibration robot 37 in the calibration wafer storage unit 5 is transferred onto the inspection table 12 in the surface inspection unit 2 by the transfer robot 27.

  The inspection table 12 is rotated by the motor 13, and a laser beam is irradiated onto the calibration wafer 37 through the light projecting unit 15. The reflected light reflected by the calibration wafer 37 is received by the light receiving unit 17, and the light reception result is input to the computer 16. The computer 16 controls the laser light source 14 based on the light reception result so that the light projection state of the laser beam onto the calibration wafer 37 is constant.

  Further, based on the inspection result of the calibration wafer 37, the voltage applied to the light receiving sensor 18 is adjusted, and the sensitivity of the light receiving sensor 18 is adjusted. Alternatively, the amplification factor of the received light signal in the signal processing unit 19 is adjusted. Alternatively, calibration is performed by an appropriate method such as both.

  When the calibration is completed, the calibration wafer 37 on the inspection table 12 is returned to the calibration wafer storage unit 5 by the transfer robot 27.

  Next, the wafer 11 to be inspected is transferred from the cassette on the cassette transfer stage 3 to the inspection table 12, and the surface inspection of the wafers 11 is sequentially executed.

  While the surface inspection of the wafer 11 is being performed, the opening 44 is opened, and clean gas is discharged from the clean gas discharge nozzle 55. A clean flow 41 is formed in the calibration wafer storage unit 5 and the clean state of the calibration wafer 37 is maintained.

  Whether or not the calibration wafer 37 is stored in the calibration wafer storage unit 5 is detected by the wafer detector 54, and the calibration wafer 37 is stored in the calibration wafer storage unit 5. In this state, the clean gas is continuously discharged from the clean gas discharge nozzle 55 regardless of whether the surface inspection by the surface inspection unit 8 is being performed, and the clean flow 41 is formed.

  Note that in a situation where the cleanliness of the transfer space 26 is reduced, such as when the surface inspection unit 8 is stopped in an emergency or when the clean unit 25 is stopped, an abnormality is determined by the control unit 31, and the rotary unit The solenoid 48 is driven to close the lid 47. By closing the lid 47, the entrainment of particles due to the change of the air flow due to the stop of the clean air flow 30 is prevented.

  Further, when the calibration wafer storage unit 5 is completely sealed in the closed state, the air flow inside may stagnate and the stored calibration wafer 37 may be contaminated by particles. In the closed state, the opening 44 is not sealed, and the lower part is partially opened.

  As shown in FIG. 9 (B), the opening 44 is partially opened, and the clean gas is continuously discharged from the clean gas discharge nozzle 55, whereby the clean flow 41 is maintained, and the calibration wafer storage unit. 5 The inside is maintained in a clean atmosphere.

  Note that a notch may be formed in the lower portion of the lid 47 so that the flow path of the clean flow 41 is ensured even when the lid 47 is completely closed.

  Further, the flow rate discharged from the clean gas discharge nozzle 55 or the discharge direction of the gas discharge hole 56 is adjusted, and the discharged clean gas collides with the surface of the calibration wafer 37 in the upper stage, and a part thereof You may make it back flow toward the said opening 44. FIG. By partially flowing back toward the opening 44, a clean gas flows out from the entire surface of the opening 44 toward the transfer space 26, and the clean air flow 30 enters the calibration wafer storage unit 5. Intrusion is prevented, and the inside of the calibration wafer storage unit 5 can be maintained at a high cleanliness.

It is a perspective view from the front of the surface inspection apparatus concerning the present invention. It is a perspective view from the back of the surface inspection apparatus concerning the present invention. It is a schematic block diagram which shows an example of the surface inspection part which this surface inspection apparatus comprises. It is a side view which shows the inside of the conveyance part of this surface inspection apparatus. It is a sectional side view of the wafer storage part for a calibration which this conveyance part comprises. It is a top view of this calibration wafer storage part. It is a front view in the state where the lid of the calibration wafer storage part was opened. It is sectional drawing of the clean gas discharge nozzle used for this wafer housing part for calibration. (A) is explanatory drawing which shows the cleaning flow in the state which the lid | cover of the calibration wafer storage part opened, (B) is explanatory drawing which shows the cleaning flow in the state which the lid | cover of the calibration wafer storage part closed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transfer part 2 Inspection part 5 Calibration wafer storage part 8 Surface inspection part 26 Transfer space 27 Transfer robot 30 Clean air flow 31 Control part 37 Calibration wafer 38 Wafer mounting plate 39 Clean flow formation means 41 Clean flow 44 Opening 47 Lid 48 Rotary solenoid 51 Wafer mounting 53 Receiving piece 54 Wafer detector 55 Clean gas discharge nozzle 56 Gas discharge hole

Claims (8)

In a surface inspection apparatus comprising an inspection unit for inspecting foreign matter and scratches on a substrate surface, and a conveyance unit for carrying in and out a substrate for an inspection object and a calibration substrate in the inspection unit, the conveyance unit is a calibration substrate. A plurality of calibration substrate storage units,
The calibration substrate storage unit is a container opened in the transport unit, and a clean gas discharge nozzle is provided so as to cross the upper part of the opening, and the clean gas is discharged from the clean gas discharge nozzle, and the clean gas is stored. Flow toward the back of the storage unit along the surface of the substrate, flow back at the back wall, forming a clean flow that flows out from the bottom of the opening,
Wherein the clean gas discharged from the clean gas discharge nozzle impinges on the surface of the calibration substrate of the upper, partly flow back, surface inspection, characterized in that it is configured so as to flow out the apertures or al apparatus. In a surface inspection apparatus comprising an inspection unit for inspecting foreign matter and scratches on a substrate surface, and a conveyance unit for carrying in and out a substrate for an inspection object and a calibration substrate in the inspection unit, the conveyance unit is a calibration substrate. A calibration substrate storage section for storing
The calibration substrate storage unit is a container that has an opening in the transport unit, a lid that opens and closes the opening, and at least one substrate mounting plate.
A clean gas discharge nozzle is provided so as to cross the upper part of the opening, and the clean gas is discharged from the clean gas discharge nozzle, and the clean gas flows toward the back of the storage portion along the surface of the stored substrate. A clean flow that turns around is formed,
The surface inspection apparatus, wherein the lid is configured to open a part of the opening in a closed state so as to maintain a clean flow inside the calibration substrate storage unit.   The surface inspection apparatus according to claim 2, wherein a part of the clean gas discharged from the clean gas discharge nozzle flows backward and flows out from the opening.   The surface inspection apparatus according to claim 2, wherein a clean air flow is formed inside the transport unit, and the clean gas discharged from the clean gas discharge nozzle is supplied independently of the clean air flow.   The surface inspection apparatus according to claim 1, wherein the calibration substrate storage unit includes a lid that opens and closes the opening, and the lid is closed when the cleanliness inside the transport unit decreases.   The surface inspection apparatus according to claim 1, wherein a part of the opening is opened so that a clean flow is maintained inside the calibration substrate storage unit in the closed state.   3. The surface according to claim 1, wherein the calibration substrate storage unit includes a substrate detector that detects the presence or absence of a substrate, and maintains the clean flow when the substrate is detected by the substrate detector. Inspection device.   The surface inspection apparatus according to claim 1, wherein the calibration substrate storage unit includes a teaching viewing window for setting a substrate storage position.

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