Wafer sensor and imaging method

Abstract

A wafer sensor according to an exemplary embodiment of the present invention is provided with a substrate, an imaging device, and a light source. The substrate contains a light-transmitting portion having a recess. The imaging device is disposed on the substrate. The light source is disposed in the recess of the substrate so that light is incident on the light-transmitting portion from the side surface of the recess and an object is irradiated with the light guided through the light-transmitting portion.

Description

Wafer-Type Sensor and Imaging Method 【0001】 Exemplary embodiments of the present disclosure relate to a wafer-type sensor and an imaging method. 【0002】 Patent Document 1 discloses a substrate-type sensor used in a semiconductor processing system. This substrate-type sensor includes a substrate-shaped base portion, a camera disposed near the edge of the base portion, and a light source disposed near the camera. 【0003】 Japanese Patent Translation of PCT No. 2021-521651 【0004】 The present disclosure provides a technology that can facilitate the assembly of a wafer-type sensor. 【0005】 In one exemplary embodiment, a wafer-type sensor is provided. The wafer-type sensor includes a substrate, an imaging device, and a light source. The substrate includes a light-transmissive portion. The light-transmissive portion has a recess including a bottom surface and a side surface intersecting the bottom surface. The imaging device is disposed on the substrate to image an object. The light source is disposed in the recess such that light is incident from the side surface of the recess into the light-transmissive portion, and the light guided through the inside of the light-transmissive portion irradiates the object. 【0006】 According to one exemplary embodiment, the wafer-type sensor can be easily assembled. 【0007】 It is a diagram showing an example of a processing system. It is a perspective view showing an example of an aligner. It is a diagram showing an example of a plasma processing apparatus. It is a plan view showing an example of a wafer-type sensor as viewed from the upper surface side. It is a partially enlarged view of FIG. 4. It is a cross-sectional view taken along line VI-VI of FIG. 5. It is an enlarged view of a main part in another example of a wafer-type sensor. It is a cross-sectional view taken along line VIII-VIII of FIG. 7. It is an enlarged view of a main part in yet another example of a wafer-type sensor. It is an enlarged view of a main part in yet another example of a wafer-type sensor. It is a cross-sectional view taken along line XI-XI of FIG. 10. 【0008】 Hereinafter, various exemplary embodiments will be described. 【0009】In one exemplary embodiment, the wafer sensor comprises a substrate, an imaging device, and a light source. The substrate includes a light-transmitting portion. The light-transmitting portion has a recess including a bottom surface and a side surface intersecting the bottom surface. The imaging device is positioned on the substrate to image an object. The light source is positioned in the recess such that light is incident on the light-transmitting portion from the side surface of the recess, and the light guided through the interior of the light-transmitting portion illuminates the object. 【0010】 In the wafer-type sensor described above, the object is illuminated by light from a light source, and then imaged by an imaging device. In this wafer-type sensor, light from a light source incident on the light-transmitting portion is guided through the inside of the light-transmitting portion and illuminates the object. In this case, the object can be properly illuminated by the light diffused inside the light-transmitting portion, thus reducing the number of light sources. Furthermore, since the substrate includes the light-transmitting portion, there is no need to fix separate light-transmitting components to the substrate. In this way, the number of parts and assembly man-hours can be reduced, making it easy to assemble the wafer-type sensor. 【0011】 In one exemplary embodiment, the light-transmitting portion may have an uneven surface that reflects light from a light source toward an object. In this configuration, light incident from the side of the light-transmitting portion can be emitted in a desired direction. 【0012】 In one exemplary embodiment, the imaging device may be positioned on a substrate to image an object below the substrate through a light-transmitting portion. The uneven surface may be formed on the upper surface of the light-transmitting portion. In this configuration, the area below can be efficiently illuminated by light guiding through the light-transmitting portion. 【0013】 In one exemplary embodiment, the imaging device may be positioned on the substrate to image an object above the substrate. The uneven surface may be formed on the underside of the light-transmitting portion. In this configuration, the area above can be efficiently illuminated by light guiding the light-transmitting portion. 【0014】In one exemplary embodiment, the imaging device may be positioned on the substrate to image an object located to the side of the substrate. The light-transmitting portion may have an outer surface facing the side of the substrate. Light from a light source may be guided through the interior of the light-transmitting portion and irradiated from the outer surface of the light-transmitting portion. In this configuration, the side can be efficiently irradiated by the light guided through the light-transmitting portion. 【0015】 In one exemplary embodiment, the outer surface of the light-transmitting portion may have a light-diffusing portion. In this configuration, the object can be illuminated uniformly. 【0016】 In one exemplary embodiment, the light-diffusing portion may be composed of a rough surface formed by blasting. In this configuration, the light-diffusing portion can be formed by fine irregularities, and light can be diffused efficiently. 【0017】 In one exemplary embodiment, the wafer sensor may further include a circuit board that controls the operation of the imaging device and the light source. In this configuration, the wafer sensor can be operated without relying on an external control device. 【0018】 In one exemplary embodiment, the wafer sensor may further include a battery to supply power to the imaging device and light source. In this configuration, the wafer sensor can be operated without relying on an external power source. 【0019】 In one exemplary embodiment, an imaging method using a wafer-type sensor is provided. The imaging method comprises the steps of: directing light from a light source into a light-transmitting portion from the side and illuminating an object with the light guided through the inside of the light-transmitting portion; and imaging the object illuminated with light using an imaging device. 【0020】 Various embodiments will be described in detail below with reference to the drawings. In each drawing, the same or corresponding parts will be denoted by the same reference numerals. 【0021】A wafer-type sensor 100 according to one exemplary embodiment is used in a processing system 1 that functions as a transport system S1. First, a processing system having a processing apparatus for processing a workpiece and a transport apparatus for transporting the workpiece to the processing apparatus will be described. Figure 1 is a diagram illustrating an example of a processing system. The processing system 1 includes tables 2a to 2d, containers 4a to 4d, a loader module LM, an aligner AN, load lock modules LL1 and LL2, process modules PM1 to PM6, a transfer module TF, and a control unit MC. The number of tables 2a to 2d, the number of containers 4a to 4d, the number of load lock modules LL1 and LL2, and the number of process modules PM1 to PM6 are not limited and may be one or more arbitrary numbers. 【0022】 The bases 2a to 2d are arranged along one edge of the loader module LM. The containers 4a to 4d are each mounted on the bases 2a to 2d. Each of the containers 4a to 4d is, for example, a container called a FOUP (Front Opening Unified Pod). Each of the containers 4a to 4d may be configured to contain a workpiece W. The workpiece W has a substantially disc shape, such as a wafer. 【0023】 The loader module LM has a chamber wall that defines a transport space under atmospheric pressure within it. A transport device TU1 is provided within this transport space. The transport device TU1 is, for example, an articulated robot and is controlled by the control unit MC. The transport device TU1 is configured to transport the workpiece W between containers 4a to 4d and the aligner AN, between the aligner AN and the load lock modules LL1 to LL2, and between the load lock modules LL1 to LL2 and the containers 4a to 4d. 【0024】The aligner AN is connected to the loader module LM. The aligner AN is configured to adjust (calibrate) the position of the workpiece W. Figure 2 is a perspective view illustrating the aligner. The aligner AN has a support base 6T, a drive unit 6D, and a sensor 6S. The support base 6T is a rotatable base about an axis extending in the vertical direction. The support base 6T is configured to support the workpiece W on it. The support base 6T is rotated by the drive unit 6D. The drive unit 6D is controlled by the control unit MC. When the support base 6T rotates due to the power from the drive unit 6D, the workpiece W placed on the support base 6T also rotates. 【0025】 Sensor 6S is an optical sensor. Sensor 6S detects the edges of the workpiece W while the workpiece W is rotating. From the edge detection results, Sensor 6S detects the amount of deviation of the angular position of the notch WN (or another marker) on the workpiece W relative to the reference angular position, and the amount of deviation of the center position of the workpiece W relative to the reference position. Sensor 6S outputs the amount of deviation of the angular position of the notch WN and the amount of deviation of the center position of the workpiece W to the control unit MC. Based on the amount of deviation of the angular position of the notch WN, the control unit MC calculates the amount of rotation of the support base 6T to correct the angular position of the notch WN to the reference angular position. The control unit MC controls the drive unit 6D to rotate the support base 6T by this amount of rotation. This corrects the angular position of the notch WN to the reference angular position. Furthermore, the control unit MC controls the position of the end effector of the transport device TU1 when receiving the workpiece W from the aligner AN, based on the amount of displacement of the center position of the workpiece W. As a result, the center position of the workpiece W coincides with a predetermined position on the end effector of the transport device TU1. 【0026】 Returning to Figure 1, load lock module LL1 and load lock module LL2 are each located between loader module LM and transfer module TF. Load lock module LL1 and load lock module LL2 each provide a pre-pressure chamber. 【0027】The transfer module TF is hermetically connected to the load lock modules LL1 and LL2 via gate valves. The transfer module TF provides a depressurized chamber. A conveying device TU2 is provided in this depressurized chamber. The conveying device TU2 is, for example, an articulated robot having a conveying arm TUa. The conveying device TU2 is controlled by the control unit MC. The conveying device TU2 is configured to convey the workpiece W between the load lock modules LL1 to LL2 and the process modules PM1 to PM6, and between any two process modules among the process modules PM1 to PM6. 【0028】 Process modules PM1 to PM6 are hermetically connected to the transfer module TF via gate valves. Each of the process modules PM1 to PM6 is a processing unit configured to perform a specific treatment, such as plasma treatment, on the workpiece W. 【0029】 The following is an example of the sequence of operations when processing the workpiece W in this processing system 1. The transport device TU1 of the loader module LM takes the workpiece W from one of the containers 4a to 4d and transports the workpiece W to the aligner AN. Next, the transport device TU1 takes the workpiece W, whose position has been adjusted, from the aligner AN and transports the workpiece W to one of the load lock modules LL1 and LL2. Next, the load lock module reduces the pressure in the pre-pressure chamber to a predetermined pressure. Next, the transport device TU2 of the transfer module TF takes the workpiece W from the load lock module and transports the workpiece W to one of the process modules PM1 to PM6. Then, one or more of the process modules PM1 to PM6 process the workpiece W. Then, the conveying device TU2 conveys the processed workpiece W from the process module to one of the load lock modules LL1 and LL2. Next, the conveying device TU1 conveys the workpiece W from one of the load lock modules to one of the containers 4a to 4d. 【0030】 As described above, this processing system 1 includes a control unit MC. The control unit MC may be a computer equipped with a processor, memory and other storage devices, a display device, input / output devices, communication devices, etc. The series of operations of the processing system 1 described above are realized by the control unit MC controlling each part of the processing system 1 according to a program stored in the storage device. 【0031】 Figure 3 shows an example of a plasma processing apparatus that can be adopted as one of the process modules PM1 to PM6. The plasma processing apparatus 10 shown in Figure 3 is a capacitively coupled plasma etching apparatus. The plasma processing apparatus 10 comprises a substantially cylindrical chamber body 12. The chamber body 12 is formed from, for example, aluminum, and its inner wall surface may be subjected to anodizing treatment. This chamber body 12 is grounded for safety. 【0032】 A substantially cylindrical support portion 14 is provided on the bottom of the chamber body 12. The support portion 14 is made of, for example, an insulating material. The support portion 14 is located inside the chamber body 12. The support portion 14 extends upward from the bottom of the chamber body 12. A stage ST is provided inside the chamber S provided by the chamber body 12. The stage ST is supported by the support portion 14. 【0033】 The stage ST has a lower electrode LE and an electrostatic chuck ESC. The lower electrode LE includes a first plate 18a and a second plate 18b. The first plate 18a and the second plate 18b are made of a metal such as aluminum and are substantially disc-shaped. The second plate 18b is provided on the first plate 18a and is electrically connected to the first plate 18a. 【0034】An electrostatic chuck ESC is provided on the second plate 18b. The electrostatic chuck ESC has a structure in which electrodes, which are conductive films, are arranged between a pair of insulating layers or insulating sheets, and has a substantially disc shape. A DC power supply 22 is electrically connected to the electrodes of the electrostatic chuck ESC via a switch 23. This electrostatic chuck ESC attracts the workpiece W by electrostatic force such as Coulomb force generated by the DC voltage from the DC power supply 22. In this way, the electrostatic chuck ESC can hold the workpiece W. 【0035】 An edge ring ER is provided on the periphery of the second plate 18b. This edge ring ER is provided so as to surround the edge of the workpiece W and the electrostatic chuck ESC. The edge ring ER has an annular plate shape. The workpiece W is conveyed onto the electrostatic chuck ESC by the conveying devices TU1 and TU2 so that the center position of the workpiece W coincides with the center position of the edge ring ER. This edge ring ER can be formed from any of various materials such as silicon, silicon carbide, or silicon oxide. 【0036】 A refrigerant flow path 24 is provided inside the second plate 18b. The refrigerant flow path 24 constitutes a temperature control mechanism. Refrigerant is supplied to the refrigerant flow path 24 from a chiller unit located outside the chamber body 12 via piping 26a. The refrigerant supplied to the refrigerant flow path 24 is returned to the chiller unit via piping 26b. In this way, refrigerant circulates between the refrigerant flow path 24 and the chiller unit. By controlling the temperature of this refrigerant, the temperature of the workpiece W supported by the electrostatic chuck ESC is controlled. 【0037】The stage ST has multiple (for example, three) through holes 25 that penetrate the stage ST. The multiple through holes 25 are formed on the inside of the electrostatic chuck ESC in a plan view. A lift pin 25a is inserted into each of these through holes 25. In Figure 3, one through hole 25 with one lift pin 25a inserted is depicted. The lift pin 25a is provided to be vertically movable within the through hole 25. The workpiece W supported on the electrostatic chuck ESC is raised by the rise of the lift pin 25a. For example, the lift pin 25a can receive the workpiece W transported by the transport device TU2 based on transport position data and place the workpiece W on the electrostatic chuck ESC. The lift pin 25a can also transfer the workpiece W placed on the electrostatic chuck ESC to the transport device TU2. 【0038】 The stage ST has multiple (for example, three) through-holes 27 that penetrate the stage ST (lower electrode LE) at a position outside the electrostatic chuck ESC in a plan view. A lift pin 27a is inserted into each of these through-holes 27. In Figure 3, one through-hole 27 with one lift pin 27a inserted is depicted. The lift pin 27a is provided to be vertically movable within the through-hole 27. The rise of the lift pin 27a causes the edge ring ER supported on the second plate 18b to rise. For example, the lift pin 27a can transfer a worn edge ring ER to the transport device TU2. The lift pin 27a can also receive a replacement edge ring ER transported by the transport device TU2 based on transport position data and place the edge ring ER in the designated position. The replacement edge ring ER may be an unused edge ring or a used edge ring with minimal wear. 【0039】 Furthermore, the plasma processing apparatus 10 is provided with a gas supply line 28. The gas supply line 28 supplies heat transfer gas, such as He gas, from the heat transfer gas supply mechanism between the upper surface of the electrostatic chuck ESC and the back surface of the workpiece W. 【0040】The plasma processing apparatus 10 also includes an upper electrode 30. The upper electrode 30 is positioned above the stage ST and opposite to the stage ST. The upper electrode 30 is supported on the upper part of the chamber body 12 via an insulating shielding member 32. The upper electrode 30 may include a top plate 34 and a support 36. The top plate 34 faces the chamber S. The top plate 34 is provided with a plurality of gas discharge holes 34a. The top plate 34 may be formed from silicon or quartz. Alternatively, the top plate 34 may be constructed by forming a plasma-resistant film, such as yttrium oxide, on the surface of an aluminum base material. 【0041】 The support 36 detachably supports the top plate 34. The support 36 may be made of a conductive material such as aluminum. The support 36 may have a water-cooling structure. A gas diffusion chamber 36a is provided inside the support 36. Multiple gas passage holes 36b that communicate with the gas discharge hole 34a extend downward from this gas diffusion chamber 36a. The support 36 also has a gas inlet 36c that guides the processed gas into the gas diffusion chamber 36a. A gas supply pipe 38 is connected to this gas inlet 36c. 【0042】 A gas source group 40 is connected to the gas supply pipe 38 via a valve group 42 and a flow controller group 44. The gas source group 40 includes multiple gas sources for multiple types of gas. The valve group 42 includes multiple valves, and the flow controller group 44 includes multiple flow controllers such as mass flow controllers. Each of the multiple gas sources in the gas source group 40 is connected to the gas supply pipe 38 via a corresponding valve in the valve group 42 and a corresponding flow controller in the flow controller group 44. 【0043】 Furthermore, in the plasma processing apparatus 10, a deposit shield 46 is detachably provided along the inner wall of the chamber body 12. The deposit shield 46 is also provided on the outer circumference of the support portion 14. The deposit shield 46 prevents etching by-products (deposits) from adhering to the chamber body 12. The deposit shield 46 can be constructed by coating an aluminum material with ceramics such as yttrium oxide. 【0044】On the bottom side of the chamber body 12 and between the support portion 14 and the side wall of the chamber body 12, an exhaust plate 48 is provided. The exhaust plate 48 can be formed, for example, by coating a ceramic such as yttrium oxide on an aluminum material. A plurality of holes penetrating in the plate thickness direction are formed in the exhaust plate 48. Below the exhaust plate 48 and in the chamber body 12, an exhaust port 12e is provided. An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52. The exhaust device 50 has a vacuum pump such as a pressure regulating valve and a turbo molecular pump. The exhaust device 50 can reduce the pressure in the space within the chamber body 12 to a desired degree of vacuum. Further, a carry-in / carry-out port 12g for the workpiece W is provided in the side wall of the chamber body 12. The carry-in / carry-out port 12g can be opened and closed by a gate valve 54. 【0045】 Further, the plasma processing apparatus 10 further includes a first high-frequency power source 62 and a second high-frequency power source 64. The first high-frequency power source 62 is a power source that generates a first high-frequency for plasma generation. The first high-frequency power source 62 generates a high-frequency having a frequency, for example, in the range of 27 to 100 MHz. The first high-frequency power source 62 is connected to the upper electrode 30 via a matching unit 66. The matching unit 66 has a circuit for matching the output impedance of the first high-frequency power source 62 and the input impedance on the load side (upper electrode 30 side). Incidentally, the first high-frequency power source 62 may be connected to the lower electrode LE via the matching unit 66. 【0046】 The second high-frequency power source 64 is a power source that generates a second high-frequency for attracting ions to the workpiece W. The second high-frequency power source 64 generates a high-frequency having a frequency, for example, within the range of 400 kHz to 13.56 MHz. The second high-frequency power source 64 is connected to the lower electrode LE via a matching unit 68. The matching unit 68 has a circuit for matching the output impedance of the second high-frequency power source 64 and the input impedance on the load side (lower electrode LE side). 【0047】In the plasma processing apparatus 10, gas from one or more selected gas sources among a plurality of gas sources is supplied to the chamber S. Further, the pressure in the chamber S is set to a predetermined pressure by the exhaust device 50. Furthermore, the gas in the chamber S is excited by the first high-frequency power from the first high-frequency power source 62. Thereby, plasma is generated. Then, the workpiece W is processed by the generated active species. Note that, if necessary, ions may be drawn into the workpiece W by the bias based on the second high-frequency power of the second high-frequency power source 64. 【0048】 Hereinafter, the wafer type sensor will be described. FIG. 4 is a plan view showing the wafer type sensor as viewed from the upper surface side. The wafer type sensor 100 shown in FIG. 4 includes a base substrate 102 (substrate), an imaging device 110, and a light source 120. The base substrate 102 has, for example, the same shape as the shape of the workpiece W, that is, a substantially disk shape. The diameter of the base substrate 102 is the same as the diameter of the workpiece W, and is, for example, 300 mm. Further, a notch 102N (or another marker) is formed at the edge of the base substrate 102. The base substrate 102 includes a light transmissive portion. An example of the base substrate 102 is formed of a light transmissive member. For example, the material constituting the base substrate 102 may be sapphire from the viewpoints of solvent resistance and hardness. Further, the base substrate 102 may be formed of quartz glass or the like. Note that the light transmissive member may be a hard transparent material through which light can be guided inside. 【0049】 A housing 104 is provided on the upper surface of the base substrate 102. The housing 104 cooperates with the base substrate 102 to define an internal space. For example, the housing 104 is fixed to the upper surface of the base substrate 102 and cooperates with the upper surface of the base substrate 102 to define an internal space. An example of the housing 104 has a disk-shaped upper wall portion 104a that is slightly smaller than the base substrate 102 and a peripheral wall portion 104b formed at the periphery of the upper wall portion 104a. The internal space defined by the housing 104 houses the imaging device 110, the light source 120, and the like. 【0050】Figure 5 is an enlarged view of part V of Figure 4. Figure 6 is a cross-sectional view along the line VI-VI in Figure 5. The housing is not shown in Figures 5 and 6. The imaging device 110 is positioned on the base substrate 102 to image a predetermined imaging area. In one exemplary embodiment, the imaging device 110 is positioned on the base substrate 102 to image an imaging area below the base substrate 102 via the base substrate 102. In this case, the imaging area is a part of an object 109A positioned below the base substrate 102. As shown in Figure 4, the wafer-type sensor 100 according to one exemplary embodiment includes a plurality (four in the illustrated example) of imaging devices 110 near the edge of the base substrate 102 along the circumferential direction of the base substrate 102. The plurality of imaging devices 110 are evenly distributed in the circumferential direction. 【0051】 The imaging device 110 is configured to include an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device). As shown in Figure 5, a rectangular pixel area, which is a light-receiving unit 111, is formed in the center of the imaging device 110. In one exemplary embodiment, since the device is configured to image downwards as described above, the light-receiving unit 111 faces downwards. That is, the light-receiving unit 111 faces the upper surface of the base substrate 102. 【0052】The light source 120 illuminates the imaging area of ​​the imaging device 110 with light. The light source 120 is controlled to light up, for example, when imaging is performed by the imaging device 110. One example of the light source 120 may be an LED (Light Emitting Diode). In one exemplary embodiment, the light source 120 has light incident on a base substrate 102, which is a light-transmitting member, from the side. In the illustrated example, a recess 105 is formed to house the light source 120 at a position radially inward from the imaging device 110. The recess 105 has a substantially rectangular shape in plan view, for example, and has a bottom surface 105a and four side surfaces 105b that intersect the bottom surface 105a. For example, the bottom surface 105a may be horizontal, and the side surfaces 105b may be perpendicular to the bottom surface 105a. One of the four side surfaces 105b (side surface 105ba) faces the imaging device 110 side. The light source 120 is housed in the recess 105 such that its light-emitting surface 120a faces the side surface 105ba. The light-emitting surface 120a of the light source 120 may be in contact with the side surface 105ba. That is, the light source 120 emits light toward the side surface 105ba. 【0053】 In one exemplary embodiment, a reflective portion 103 is formed on the base substrate 102 so that light L emitted from the light source 120 is guided through the interior of the base substrate 102 to illuminate the imaging area. The reflective portion 103 reflects light from the light source 120 toward the imaging area. In the illustrated example, since it is necessary to illuminate the imaging area below the base substrate, the reflective portion 103 is formed on the upper surface of the base substrate 102. In one example, the area in which the reflective portion 103 is formed surrounds the pixel area of ​​the imaging device 110 and has a rectangular frame shape. 【0054】For example, the reflective portion 103 is composed of an uneven surface formed on the surface of the base substrate 102. As shown in Figure 6, one example of a reflective portion 103 is formed by the aggregation of a plurality of inverted pyramidal recesses. That is, the reflective portion 103 may be formed by a plurality of inclined surfaces formed on the surface of the base substrate 102. Such a reflective portion 103 may be formed by, for example, cutting or embossing. Note that although four recesses are shown in the cross-sectional view in Figure 6, this is because the recesses are depicted in an exaggerated manner, and in reality, there may be many more fine recesses formed. 【0055】 The imaging device 110 and the light source 120 may be controlled by the circuit board 106. In one exemplary embodiment, the wafer sensor 100 includes a circuit board 106 and a battery 107 on a base substrate 102. 【0056】 The circuit board 106 is provided on the upper surface of the base board 102. The circuit board 106 may be, for example, a so-called printed circuit board. A group of wires for electrically connecting the circuit board 106 to the multiple imaging devices 110 and the multiple light sources 120 is provided between the circuit board 106 and the multiple imaging devices 110 and the multiple light sources 120. The circuit board 106 has a processor, a memory device, a communication device, etc., and controls the operation of the imaging devices 110 and the light sources 120, as well as managing the imaging data from the imaging devices 110. 【0057】 The battery 107 is positioned on the base board 102 adjacent to the circuit board 106. The battery 107 is connected to the circuit board 106 and supplies power to the circuit board 106, as well as to the imaging device 110 and the light source 120 via the circuit board 106. 【0058】The wafer-type sensor 100 described above is used for imaging within the chamber S. In one exemplary embodiment, the wafer-type sensor 100 is transported into the chamber S from one of the containers 4a to 4d by transport devices TU1 and TU2. At this time, the circumferential position of the wafer-type sensor 100 is adjusted by the aligner AN. Inside the chamber S, the imaging device 110 of the wafer-type sensor 100 images the lower imaging area while the wafer-type sensor 100 is supported by the raised lift pin 25a. That is, under the control of the circuit board 106, light L from the light source 120 is incident from the side surface 105ba of the base substrate 102, guided through the interior of the base substrate 102, and the light L emitted from the lower surface of the base substrate 102 irradiates the imaging area. The imaging area irradiated with light is then imaged by the imaging device 110. 【0059】 In one example, the offset between the center positions of the electrostatic chuck ESC and the edge ring ER may be derived by imaging both the outer edge of the electrostatic chuck ESC and the inner edge of the edge ring ER within the same field of view. Alternatively, the circuit board 106 may be imaged after determining that the wafer sensor 100 is supported by the lift pin 25a by counting the transport time by the transport devices TU1 and TU2. 【0060】 As described above, in one exemplary embodiment, a wafer-type sensor 100 is provided. The wafer-type sensor 100 comprises a base substrate 102, an imaging device 110, and a light source 120. The base substrate 102 includes a light-transmitting portion that transmits light. In the above exemplary embodiment, the entire base substrate 102 is formed of a light-transmitting member. The imaging device 110 is positioned on the base substrate 102 to image an object 109A. The light source 120 is positioned on the base substrate 102 such that light is incident on the base substrate 102, which is a light-transmitting member, from the side, and the light guided through the interior of the base substrate 102 irradiates the object 109A. 【0061】In the wafer-type sensor 100 described above, the imaging area is illuminated by light from the light source 120, and the imaging device 110 then images the imaging area. In this wafer-type sensor 100, light from the light source 120 incident on the base substrate 102 is guided through the interior of the base substrate 102 and illuminates the imaging area. In this case, the imaging area can be properly illuminated by the light diffused (scattered) inside the base substrate 102, thus reducing the number of light sources 120. Furthermore, since at least a part of the base substrate 102 is a light-transmitting material, there is no need to fix a separate light-transmitting material to the base substrate 102. In this way, the number of parts and assembly man-hours can be reduced, making it easy to assemble the wafer-type sensor. 【0062】 In one exemplary embodiment, the base substrate 102 may have a reflective portion 103 (uneven surface) formed thereon that reflects light from the light source 120 toward the imaging area. In this configuration, light incident from the side of the base substrate 102 can be emitted in a desired direction. 【0063】 In one exemplary embodiment, the imaging device 110 is positioned on the base substrate 102 to image an imaging area below the base substrate 102 via the base substrate 102. The reflective portion 103 may be formed on the upper surface of the base substrate 102. In this configuration, the area below can be efficiently illuminated by light guiding the base substrate 102. 【0064】 In one exemplary embodiment, the reflective portion 103 may be formed by irregularities formed on the surface of the base substrate 102. In this configuration, there is no need to separately prepare the components that make up the reflective portion 103, thus preventing the assembly of the wafer-type sensor from becoming complicated. 【0065】 In one exemplary embodiment, the wafer-type sensor 100 may include a circuit board 106 that controls the operation of the imaging device 110 and the light source 120. In this configuration, the wafer-type sensor 100 can be operated without relying on an external control device. 【0066】In one exemplary embodiment, the wafer sensor 100 may include a battery 107 that supplies power to the imaging device 110 and the light source 120. In this configuration, the wafer sensor 100 can be operated without relying on an external power source. 【0067】 Figure 7 is an enlarged view of the main part of a wafer-type sensor in another exemplary embodiment. Figure 8 is a cross-sectional view along the line VIII-VIII in Figure 7. The wafer-type sensor 200 shown in Figures 7 and 8 comprises a base substrate 202, an imaging device 210, and a light source 220. The base substrate 202 differs from the base substrate 102 only in that it does not have a reflective portion 103. The imaging device 210 is positioned on the base substrate 202 to image an imaging area on the side of the base substrate 202. In this case, the imaging area is a part of an object 109B positioned on the side of the base substrate 202. The imaging device 210 is positioned such that the light-receiving portion 211 faces radially outward. The light source 220 may have the same configuration as the light source 120 and is housed in a recess 105 formed in the base substrate 202. The optical axis of the light source 220 and the optical axis of the imaging device 210 coincide in a plan view and are aligned with the radial direction of the base substrate 202. Light from the light source 220 is guided through the interior of the base substrate 202 and irradiates from the outer surface 202a of the base substrate 202. The outer surface 202a faces outward from the base substrate 202. 【0068】 In the above exemplary embodiment, the wafer-type sensor 200 is transported from one of the containers 4a to 4d into the chamber S by transport devices TU1 and TU2. Inside the chamber S, the imaging device 210 of the wafer-type sensor 200, while placed on the electrostatic chuck ESC, images the inner wall (depot shield 46) of the chamber body 12 on the side. Specifically, under the control of the circuit board 106, light from the light source 220 is incident from the side surface 105ba of the base substrate 202, guided through the interior of the base substrate 202, and the light emitted from the outer surface 202a of the base substrate 202 irradiates the imaging area. The imaging area irradiated with light is then imaged by the imaging device 210. 【0069】As described above, in other exemplary embodiments, the imaging device 210 is positioned on the base substrate 202 to image an imaging area on the side of the base substrate 202. Light from the light source 220 can be guided through the interior of the base substrate 202 (light-transmitting member) and emitted from the outer surface 202a. In this configuration, the sides can be efficiently illuminated by the light guiding through the base substrate 202. 【0070】 Figure 9 is a magnified view of a key part of yet another example of a wafer-type sensor. The wafer-type sensor 300 shown in Figure 9 comprises a base substrate 302, an imaging device 210, and a light source 220. The base substrate 302 differs from the base substrate 202 only in that it has a light diffusion portion 303. The light diffusion portion 303 is formed on the outer surface 302a of the base substrate 302, on the light emission surface from the light source 220. The light diffusion portion 303 is composed of a rough surface with fine irregularities that diffuse the emitted light. In one example, the light diffusion portion 303 may be formed by blasting the outer surface 302a. 【0071】 As described above, the outer surface 302a of the base substrate 302 (light-transmitting member) has a light-diffusing portion 303 that diffuses light. With this configuration, it is easy to evenly illuminate the imaging area, which is part of the object 109C located to the side of the base substrate 302. 【0072】 Furthermore, the light diffusion section 303 is blast-treated. In this configuration, the light diffusion section 303 can be formed by fine irregularities, allowing for efficient light diffusion. 【0073】 Figure 10 is an enlarged view of a key part of yet another example of a wafer-type sensor. Figure 11 is a cross-sectional view along the line XI-XI in Figure 10. The wafer-type sensor 400 shown in Figures 10 and 11 comprises a base substrate 402, an imaging device 410, and a light source 420. The base substrate 402 differs from the base substrate 102 only in that it has a reflective portion 403 instead of the reflective portion 103. 【0074】In the illustrated example, since it is necessary to illuminate the imaging area above the base substrate 402 with light, the reflective portion 403 is formed on the lower surface of the base substrate 402. In one example, the reflective portion 403 is formed to surround the imaging device 410 in a plan view and has a rectangular frame shape. In the illustrated example, the inner edge of the reflective portion 403 is located inside the periphery of the imaging device 410. The inner edge of the reflective portion 403 may, for example, coincide with the periphery of the imaging device 410. The shape of the reflective portion 403 is the same as that of the reflective portion 103 and is composed of an uneven surface formed on the surface of the base substrate 402. 【0075】 The imaging device 410 is positioned on the base substrate 402 to image an imaging area above the base substrate 402. In this case, the imaging area is a part of the object 109D positioned above the base substrate 402. The imaging device 410 is positioned so that the light receiving unit 411 faces upward. The light source 420 may have the same configuration as the light source 120 and is housed in a recess 105 formed in the base substrate 402. Light from the light source 420 is guided through the interior of the base substrate 402 and irradiated from the upper surface of the base substrate 402. Although the housing 104 is not shown in Figures 10 and 11, the wafer-type sensor 400 may have a housing 104 made of a transparent material. In this case, light from the light source 420 passes through the housing 104 and irradiates the object 109D. The housing 104 may also have an opening in the area above the imaging device 410. In this case, light from the light source 420 is irradiated onto the object 109D through the aperture, and the imaging device 410 images the object 109D through the aperture. 【0076】In the above exemplary embodiment, the wafer-type sensor 400 is transported from one of the containers 4a to 4d into the chamber S by transport devices TU1 and TU2. Inside the chamber S, the imaging device 410 of the wafer-type sensor 400, while placed on the electrostatic chuck ESC, images the upper wall (top plate 34) of the upper chamber body 12. Specifically, under the control of the circuit board 106, light from the light source 420 is incident from the side surface 105ba of the base substrate 402, guided through the interior of the base substrate 402, and the light emitted from the upper surface of the base substrate 402 irradiates the imaging area. The imaging area irradiated by the light is then imaged by the imaging device 410. 【0077】 As described above, in yet another exemplary embodiment, the imaging device 410 is positioned on the base substrate 402 to image an imaging area above the base substrate 402. The reflective portion 403 is formed on the lower surface of the base substrate 402. In this configuration, the area above can be efficiently illuminated by light guiding the base substrate 402 (light-transmitting member). 【0078】 Although various exemplary embodiments have been described above, the invention is not limited to the exemplary embodiments described above, and various omissions, substitutions, and modifications may be made. Furthermore, it is possible to combine elements from different embodiments to form other embodiments. 【0079】 For example, the number and position of imaging devices and light sources are not limited to the above configuration. As an example, an example in which four imaging devices are provided in the circumferential direction is shown, but there may be three or fewer imaging devices provided in the circumferential direction, or five or more. 【0080】 Furthermore, although a wafer-type sensor 100 for imaging downwards, wafer-type sensors 200 and 300 for imaging to the sides, and a wafer-type sensor 400 for imaging upwards have been shown, these may be combined with each other. For example, an imaging device for imaging downwards, an imaging device for imaging to the sides, and an imaging device for imaging upwards may be mounted on a single base substrate. 【0081】Furthermore, although an example was shown in which the entire base substrate is formed from a light-transmitting material, only a portion of the base substrate may be formed from the light-transmitting material. In addition, the imaging device, light source, and light-transmitting material may be chipped and placed on the base substrate. 【0082】 From the above description, it will be understood that the various embodiments of this disclosure are described herein for illustrative purposes and can be modified in various ways without departing from the scope and spirit of this disclosure. Accordingly, the various embodiments disclosed herein are not intended to limit the scope and spirit, and the true scope and spirit are shown by the appended claims. 【0083】Various exemplary embodiments included in this disclosure are described below: [1] A wafer-type sensor comprising: a substrate including a light-transmitting portion having a recess including a bottom surface and a side surface intersecting the bottom surface; an imaging device disposed on the substrate to image an object; and a light source disposed in the recess such that light is incident on the light-transmitting portion from the side surface of the recess and the light guided through the interior of the light-transmitting portion illuminates the object. [2] The wafer-type sensor according to [1], wherein the light-transmitting portion has an uneven surface that reflects light from the light source toward the object. [3] The wafer-type sensor according to [2], wherein the imaging device is disposed on the substrate to image an object below the substrate via the light-transmitting portion, and the uneven surface is formed on the upper surface of the light-transmitting portion. [4] The wafer-type sensor according to [2], wherein the imaging device is disposed on the substrate to image an object above the substrate, and the uneven surface is formed on the lower surface of the light-transmitting portion. [5] The wafer-type sensor according to [1], wherein the imaging device is positioned on the substrate to image the object located to the side of the substrate, the light-transmitting portion has an outer surface facing the side of the substrate, and light from the light source is guided through the inside of the light-transmitting portion and irradiated from the outer surface of the light-transmitting portion. [6] The wafer-type sensor according to [5], wherein the outer surface has a light-diffusing portion. [7] The wafer-type sensor according to [6], wherein the light-diffusing portion is a rough surface formed by blasting. [8] The wafer-type sensor according to any one of [1] to [7], further comprising a circuit board for controlling the operation of the imaging device and the light source. [9] The wafer-type sensor according to any one of [1] to [8], further comprising a battery for supplying power to the imaging device and the light source.

[10] An imaging method using a wafer-type sensor, the wafer-type sensor comprising: a substrate including a light-transmitting portion having a recess including a bottom surface and a side surface intersecting the bottom surface; an imaging device disposed on the substrate; and a light source disposed in the recess, the imaging method comprising: a step of illuminating an object with light from the light source incident on the light-transmitting portion from the side surface and guided through the inside of the light-transmitting portion; and an imaging method of imaging the object illuminated with the light using the imaging device. 【0084】 100...wafer-type sensor, 102...base substrate (substrate), 103...reflective section (uneven surface), 110...imaging device, 120...light source.

Claims

1. A wafer-type sensor comprising: a substrate including a light-transmitting portion having a recess including a bottom surface and a side surface intersecting the bottom surface; an imaging device disposed on the substrate to image an object; and a light source disposed in the recess such that light is incident on the light-transmitting portion from the side surface of the recess and guided through the interior of the light-transmitting portion to illuminate the object.

2. The wafer-type sensor according to claim 1, wherein the light-transmitting portion has an uneven surface that reflects light from the light source toward the object.

3. The wafer-type sensor according to claim 2, wherein the imaging device is arranged on the substrate to image the object below the substrate through the light-transmitting portion, and the uneven surface is formed on the upper surface of the light-transmitting portion.

4. The wafer-type sensor according to claim 2, wherein the imaging device is arranged on the substrate to image the object above the substrate, and the uneven surface is formed on the lower surface of the light-transmitting portion.

5. The wafer-type sensor according to claim 1, wherein the imaging device is arranged on the substrate to image the object located to the side of the substrate, the light-transmitting portion has an outer surface facing the side of the substrate, and light from the light source is guided through the inside of the light-transmitting portion and irradiated from the outer surface of the light-transmitting portion.

6. The wafer-type sensor according to claim 5, wherein the outer surface has a light-diffusing portion.

7. The wafer-type sensor according to claim 6, wherein the light-diffusing portion is composed of a rough surface formed by blasting.

8. The wafer-type sensor according to claim 1, further comprising a circuit board for controlling the operation of the imaging device and the light source.

9. The wafer-type sensor according to claim 1, further comprising a battery for supplying power to the imaging device and the light source.

10. An imaging method using a wafer-type sensor, wherein the wafer-type sensor comprises a substrate including a light-transmitting portion having a recess including a bottom surface and a side surface intersecting the bottom surface, an imaging device disposed on the substrate, and a light source disposed in the recess, and the imaging method comprises the steps of: sending light from the light source into the light-transmitting portion from the side surface and irradiating an object with the light guided through the inside of the light-transmitting portion; and imaging the object irradiated with the light using the imaging device.

Images