Stage and light irradiation method

Abstract

To provide a stage and a light irradiation method capable of improving in-plane uniformity of light intensity distribution of light with which an object to be irradiated is irradiated.SOLUTION: The stage 18 includes a translucent portion 70 that constitutes a placement surface of an irradiation target and has light transmissivity, an illumination unit 50 that is disposed on a side of the translucent portion 70 opposite to the irradiation target and emits light toward the translucent portion 70, and a light diffusion portion 80 that is disposed between the translucent portion 70 and the illumination unit 50 and at a position separated from the translucent portion 70 toward the illumination unit 50 and transmits light from the illumination unit 50 while diffusing the light.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an inspection apparatus and an inspection method for inspecting electrical characteristics of a back-illuminated imaging device. [Background technology]

[0002] Patent Document 1 discloses an inspection device that inspects the electrical characteristics of a backside illuminated imaging device formed on a semiconductor wafer.

[0003] The inspection device disclosed in Patent Document 1 includes a stage serving as a mounting table on which a semiconductor wafer is placed. The semiconductor wafer is placed on this stage so that the back surface (the surface opposite to the side on which the wiring layer is provided) of a back-illuminated imaging device faces the stage. The stage includes a flat plate member made of a light-transmitting material, and has a transmission section on which the semiconductor wafer is placed, and a light-emitting section that is disposed opposite the semiconductor wafer across the transmission section and emits light toward the transmission section. With this configuration, light from the light-emitting section disposed opposite the semiconductor wafer on the stage is irradiated onto the semiconductor wafer (the back surface of the back-illuminated imaging device), making it possible to inspect the electrical characteristics of the back-illuminated imaging device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-68329 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the inspection device disclosed in Patent Document 1, the transmission section has a flat plate member made of transparent glass, and the light exit surface (the surface facing the semiconductor wafer) or the light entrance surface (the surface opposite the semiconductor wafer) of the flat plate member is configured as a sand-rubbed surface. In such a configuration where the transmission section has a diffusion function (a sand-rubbed surface), it is difficult to ensure a sufficient distance between the diffusion function of the transmission section and the semiconductor wafer. Therefore, if this distance is too short, a sufficient diffusion effect may not be obtained for the light from the light exit section, and achieving a uniform light intensity distribution of the light emitted from the transmission section has become an issue. In particular, with the recent trend toward higher density and smaller imaging devices, improving the in-plane uniformity of the light intensity distribution has become even more necessary.

[0006] The present invention has been made in consideration of such problems, and aims to provide an inspection apparatus and an inspection method that can improve the in-plane uniformity of the light intensity distribution of light irradiated onto a back-illuminated imaging device. [Means for solving the problem]

[0007] In order to achieve the above object, the inspection apparatus of the present invention is an inspection apparatus for inspecting a back-illuminated imaging device formed on a semiconductor wafer, and includes a stage on which the semiconductor wafer is placed with the back surface of the imaging device facing the stage, and the stage includes a flat light-transmitting member and has a light-transmitting section on which the semiconductor wafer is placed, an illumination section that is arranged in a position facing the semiconductor wafer with the light-transmitting section in between and emits light toward the light-transmitting section, and a light diffusion section that is arranged between the light-transmitting section and the illumination section and is spaced from the light-transmitting section toward the illumination section, and through which light from the illumination section passes while diffusing.

[0008] In one aspect of the present invention, it is preferable that the light transmitting portion includes a heater that heats the light transmitting member.

[0009] In one aspect of the present invention, the heater has a transparent conductive film and a pair of electrodes for supplying power to the transparent conductive film, and it is preferable that the transparent conductive film and the pair of electrodes are formed on the surface of the light-transmitting member facing the light diffusion portion.

[0010] In one embodiment of the present invention, it is preferable that the light-transmitting member is formed in a rectangular shape in a planar view, the pair of electrodes are arranged parallel to and opposite each other along two opposing edges of the transparent glass, and the transparent conductive film is formed in a rectangular shape in a planar view between the pair of electrodes.

[0011] In one aspect of the present invention, the light transmitting portion preferably has a light reflection preventing portion that suppresses reflection of light irradiated from the illumination portion toward the semiconductor wafer.

[0012] In one aspect of the present invention, the light-antireflection portion is preferably a light-antireflection film formed in a film-like shape on the surface of the light-transmitting member on the side of the light-diffusing portion.

[0013] In order to achieve the above-mentioned object, the inspection method of the present invention is an inspection method for inspecting a back-illuminated imaging device formed on a semiconductor wafer, and includes a wafer placing step of placing the semiconductor wafer on a stage with the back surface of the imaging device facing the stage, a contact step of bringing probe needles of a probe card into contact with electrodes on the front surface of the imaging device, an illumination step of irradiating light onto the back surface of the imaging device, and an inspection step of inspecting the imaging device with the contact step and the illumination step having been performed, wherein the stage is positioned between the light-transmitting section and the illumination section, spaced from the light-transmitting section toward the illumination section, and has a light diffusion section through which light from the illumination section passes while being diffused, and the illumination step emits light from the illumination section, diffuses the emitted light by the light diffusion section, and irradiates the diffused light onto the back surface of the imaging device via the light-transmitting section. [Effects of the Invention]

[0014] According to the present invention, it is possible to improve the in-plane uniformity of the light intensity distribution of light irradiated onto a back-illuminated imaging device. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a plan view of a wafer on which an imaging device is formed. [Figure 2] FIG. 2 is a cross-sectional view showing a schematic configuration of the imaging device. [Figure 3] FIG. 3 is a front view showing a schematic configuration of the inspection device according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a schematic configuration of the stage. [Figure 5] FIG. 5 is a plan view showing a schematic configuration of the heater. [Figure 6] FIG. 6 is a flowchart showing an example of an inspection method using the inspection device of the embodiment. [Figure 7] FIG. 7 is an explanatory diagram for explaining the difference in effect between a circular heater and a rectangular heater. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an inspection device and an inspection method according to the present invention will be described in detail below with reference to the accompanying drawings.

[0017] First, before describing the inspection device (prober) 10 (see FIG. 3) according to the embodiment, we will describe a back-illuminated imaging device (hereinafter sometimes abbreviated as "imaging device") 100 (see FIGS. 1 and 2) whose electrical characteristics are inspected by the inspection device 10 according to the embodiment.

[0018] Fig. 1 is a plan view of a semiconductor wafer (hereinafter abbreviated as "wafer") W on which an imaging device 100 is formed, and Fig. 2 is a cross-sectional view showing a schematic configuration of the imaging device 100. A plurality of imaging devices 100 shown in Fig. 2 are formed on the surface of a disk-shaped wafer W as shown in Fig. 1.

[0019] The imaging device 100 is a type of solid-state imaging element, and as shown in Fig. 2, includes a photodiode 102, which is a light receiving element, and a wiring layer 106 having a plurality of wirings 104. When the wiring layer 106 side is the front side of the wafer W, the imaging device 100 also includes a lens 108 for causing the photodiode 102 to receive light L irradiated onto the back side of the wafer W. A filter 110 is provided between the lens 108 and the photodiode 102, and the filter 110 includes a red color filter 112, a blue color filter 114, and a green color filter 116.

[0020] A plurality of electrode pads 118 are formed on the surface of the imaging device 100 (the same as the surface of the wafer W), and these electrode pads 118 are electrically connected to the wiring 104 of the wiring layer 106. The wiring 104 has a function of inputting an electrical signal to a circuit element inside the imaging device 100, as well as a function of outputting an electrical signal from the circuit element to the outside of the imaging device 100. As shown in FIG. 1, a non-device formation region 120 where no imaging device 100 exists is formed on the outer periphery of the wafer W. This non-device formation region 120 functions as a region used when the wafer W is transported (loaded and unloaded), when the wafer W is fixed, etc.

[0021] Next, the inspection device 10 of the embodiment will be described. Fig. 3 is a front view showing a schematic configuration of the inspection device 10 of the embodiment, and shows the internal structure of the inspection device 10.

[0022] The inspection apparatus 10 inspects the electrical characteristics of a plurality of imaging devices 100 (see FIG. 1) formed on a wafer W. As shown in FIG. 3, the inspection apparatus 10 includes a prober chamber 12, a loader chamber 14 disposed adjacent to the prober chamber 12, and a tester 16 disposed so as to cover the prober chamber 12 from above.

[0023] The prober chamber 12 is equipped with a stage 18, on which a wafer W is placed. The stage 18 is an example of a stage of the present invention. The stage 18 also has a fixing means (not shown) for fixing, for example, a non-device formation region 120 (see FIG. 1 ) of the wafer W to the stage 18 in order to fix the position of the wafer W relative to the stage 18. Furthermore, the stage 18 is equipped with a movement and rotation mechanism that moves in three axial directions (X, Y, and Z) and rotates around the Z axis in order to bring probe needles 22 of a probe card 20 (described later) into contact with electrode pads 118 on the surface of the wafer W.

[0024] The probe card 20 is disposed above the stage 18 in the prober chamber 12 so as to face the stage 18. The probe card 20 has a plurality of probe needles 22 formed to correspond to a plurality of electrode pads 118 on the wafer W.

[0025] The probe card 20 is connected to the tester 16 via an interface 24. When each probe needle 22 is brought into contact with an electrode pad 118 of the imaging device 100, each probe needle 22 has the function of supplying power and signals sent from the tester 16 via the interface 24 to the imaging device 100, and the function of transmitting signals from the imaging device 100 to the tester 16 via the interface 24.

[0026] The relative positions of the probe card 20 and the imaging device 100 are adjusted by the above-mentioned movement and rotation mechanism provided on the stage 18, and this movement and rotation mechanism also brings the electrode pads 118 into contact with the probe needles 22. More specifically, the movement and rotation mechanism moves the stage 18 in the horizontal direction and rotates it as necessary to position the electrode pads 118 below the probe needles 22. Thereafter, the movement and rotation mechanism moves the stage 18 upward. This operation brings the electrode pads 118 into contact with the probe needles 22.

[0027] The loader chamber 14 has a container (not shown) for storing wafers W, and a transport unit (not shown) for removing the wafers W stored in the container and transporting them to the stage 18 of the prober chamber 12. The transport unit also has the function of removing the wafers W from the stage 18 after the inspection of the electrical characteristics of the imaging device 100 has been completed, and returning and storing them in the container.

[0028] The inspection device 10 has a controller 26. The controller 26 is connected to the stage 18 via wiring 28, and also connected to a computer 32 via wiring 30. The controller 26 controls the irradiation of light by an illumination unit 50 (see FIG. 4) described later on the stage 18 based on an input signal from the computer 32. Furthermore, a controller 27 serving as a prober CPU controls a heater 60 (see FIG. 4) described later on the stage 18 based on an input signal from a temperature measurement unit (not shown) that measures the temperature of the stage 18.

[0029] The computer 32 includes a CPU (Central Processing Unit: not shown) and memories such as a ROM (Read Only Memory: not shown) and a RAM (Random Access Memory: not shown).

[0030] The CPU is an example of a processor, and functions as a control unit of the inspection device 10 by executing programs stored in the memory. The ROM stores programs executed by the CPU and various data required for control, etc. The RAM is used as a working area when the CPU performs various processes.

[0031] The computer 32 is also connected to a display unit 34. As the display unit 34, for example, an LCD (Liquid Crystal Display), an organic EL display (Organic Light Emitting Diode), or a touch panel display equipped with a touch panel can be adopted.

[0032] On the other hand, the tester 16 is connected to a computer 32 via a wire 38. The computer 32 judges whether the imaging device 100 is good or bad based on the signal sent from the imaging device 100 via the tester 16.

[0033] The inspection device 10 also includes an operation unit 40. The operation unit 40 is used by an operator to input instructions and to display information to the operator, and employs, for example, a display panel 42 having a touch panel or a keyboard.

[0034] According to the inspection apparatus 10 configured as described above, when inspecting the electrical characteristics of the imaging device 100, the computer 32 transmits data to the tester 16 connected to the imaging device 100 (see FIG. 1) via the probe needles 22. The computer 32 then determines, based on the electrical signal from the tester 16, whether the transmitted data has been correctly processed by the tester 16.

[0035] Next, we will explain the configuration of the stage 18. Figure 4 is a cross-sectional view showing a schematic configuration of the stage 18. In Figure 4, in order to explain the contents of the present invention in an easy-to-understand manner, the sizes of some components are exaggerated rather than shown to their actual dimensions.

[0036] The wafer W is placed on the stage 18 with the back surface (the surface on the lens 108 side) of the imaging device 100 (see FIG. 2) facing the stage 18. As shown in FIG. 4, the stage 18 has a light-transmitting section 70, an illumination section 50, and a light diffusion section 80. The light-transmitting section 70 is an example of the light-transmitting section of the present invention, the illumination section 50 is an example of the illumination section of the present invention, and the light diffusion section 80 is an example of the light diffusion section of the present invention.

[0037] The light-transmitting section 70 includes transparent glass 72, which is an example of a flat, light-transmitting member, and the wafer W is placed with the back surface of the wafer W abutting against an upper surface 72A of the transparent glass 72. That is, the upper surface 72A of the transparent glass 72 is configured as a surface on which the wafer W is placed on the stage 18. Note that the transparent glass 72 in this example does not have holes for lift pins for loading and unloading the wafer W, and the wafer W is loaded and unloaded by an upper surface transfer mechanism that supports and transfers the non-device formation region 120 of the wafer W.

[0038] The transparent glass 72 is configured to have a size and shape such that when a wafer W is placed on an upper surface 72A of the transparent glass 72, the outer periphery WA of the wafer W does not extend beyond an edge 72B of the transparent glass 72. Specifically, the transparent glass 72 of the embodiment is preferably configured to have a rectangular shape such as a square or a rectangle in plan view in order to improve (uniformize) the temperature distribution of the transparent glass 72 by the heater 60, which will be described later.

[0039] The rectangular transparent glass 72 has at least one side (one side if the transparent glass 72 is square, or the shorter side if the transparent glass 72 is rectangular) longer than the diameter of the wafer W (the diameter if the wafer W is circular, or the longer diameter if the wafer W is elliptical). This allows the wafer W to be placed on the upper surface 72A of the transparent glass 72 so that its outer periphery WA does not extend beyond the edge 72B of the transparent glass 72. For example, if the diameter of the semiconductor wafer W is 300 mm, it is preferable that one side of the transparent glass 72 is approximately 350 mm. Note that as long as the transparent glass 72 that forms the mounting surface for the wafer W is rectangular, the planar shape of the entire stage 18 is not limited to a rectangular shape and may be a circular shape or a polygonal shape. In addition, a vacuum groove (not shown) that holds the outer periphery of the wafer W is arranged in an arc shape on the upper surface 72A of the transparent glass 72. Since the upper surface 72A of the transparent glass 72 may be damaged by contact with the wafer W, the light-transmitting portion 70 is made replaceable.

[0040] The transparent glass 72 does not have a light diffusion treatment such as sand grinding on the upper surface 72A or the lower surface 72C. In other words, the upper surface 72A and the lower surface 72C of the transparent glass 72 are formed as smooth surfaces, and the transparent glass 72 itself does not have a light diffusion function. In addition, the transparent glass 72 may be made of inorganic glass such as quartz glass, soda lime glass, aluminosilicate glass, or borosilicate glass. The transparent glass 72 is colorless and transparent.

[0041] 4, the illumination unit 50 is disposed at a position facing the wafer W with the light-transmitting unit 70 sandwiched therebetween. The illumination unit 50 also has a light source that emits light toward the light-transmitting unit 70, i.e., toward the wafer W. The illumination unit 50 in this example has, as the light source, a plurality of LEDs (Light Emitting Diodes) 52, for example, which are disposed on an LED substrate 54. A wiring pattern (not shown) for controlling the LEDs 52 is formed on the LED substrate 54.

[0042] Each of the LEDs 52 emits light that has directivity in a direction toward the wafer W and that includes light with a wavelength within the inspection range of the image capture device 100. The light with a wavelength within the inspection range is, for example, light with a wavelength within the visible light range, but depending on the type of image capture device 100, the light may also include light with a wavelength outside the visible light range, such as infrared light.

[0043] On the LED substrate 54, the LED arrangement region where the LEDs 52 are arranged is set to an area that overlaps with the wafer W fixed to the stage 18 when the stage 18 is viewed from above. Furthermore, from the viewpoint of effectively illuminating the entire wafer W, it is preferable that the size of the LED arrangement region is approximately equal to or slightly larger than the wafer W. Furthermore, from the viewpoint of illuminating the entire wafer W with approximately uniform brightness, it is preferable that the LEDs 52 are provided at equal intervals within the LED arrangement region. The turning on and off of all the LEDs 52 is performed by the controller 26 (see FIG. 3), and the controller 26, for example, collectively controls all the LEDs 52 as a single unit.

[0044] The illumination unit 50 also has a heat sink 56. The heat sink 56 is provided on the lower surface of the LED substrate 54, opposite to the upper surface where the LEDs are arranged. The heat sink 56 has the function of radiating heat of the LEDs 52, which is transferred from the LEDs 52 to the LED substrate 54, to the outside of the stage 18, and is made of a metal material such as aluminum, which has high thermal conductivity. The heat sink 56 may be provided with a cooling mechanism for cooling the LEDs 52.

[0045] The above is the configuration of the illumination unit 50, but instead of the LED 52, a high-intensity discharge lamp such as a xenon lamp or a halogen lamp may be used as the illumination unit 50.

[0046] 4, the light diffusion section 80 is disposed between the illumination section 50 and the light-transmitting section 70. Specifically, the light diffusion section 80 is disposed at a distance from the light-transmitting section 70 toward the illumination section 50. The light diffusion section 80 is also disposed at a distance from the illumination section 50 toward the light-transmitting section 70. That is, the light diffusion section 80 in this example is provided independently for the illumination section 50 and the light-transmitting section 70.

[0047] The light diffusion unit 80 has a function of transmitting light from the illumination unit 50 while diffusing it. As the light diffusion unit 80, for example, one having a transparent sheet 82 and having a function of diffusing light by providing depressions on the surface thereof is adopted. The sheet 82 may be made of glass or may be made of a resin such as polycarbonate or polystyrene. In the case of a resin, it is possible to form a large number of small depressions with diameters of several microns to several hundred microns on the surface of the sheet 82, which has the advantage of being able to more effectively diffuse light from the LEDs 52, which are point light sources, compared to, for example, a glass sheet.

[0048] The light diffusion unit 80 configured as described above diffuses and transmits light emitted from the illumination unit 50 toward the wafer W. At this time, the light emitted from the light diffusion unit 80 has a substantially uniform light intensity distribution in a plane parallel to the wafer W. The light enters the transparent glass 72 from the lower surface 72C of the transparent glass 72, exits from the upper surface 72A, and illuminates the back surface of the wafer W. This makes it possible to illuminate the entire back surface of the wafer W fixed to the stage 18 with substantially uniform brightness.

[0049] The light-transmitting section 70 also has a heater 60. The heater 60 is disposed between the transparent glass 72 and the light diffusion section 80. The heater 60 heats the transparent glass 72, thereby adjusting the temperature of the imaging device 100 placed on the transparent glass 72 to a desired inspection temperature.

[0050] Fig. 5 is a plan view showing a schematic configuration of the heater 60 of this example. The heater 60 is made of a light-transmitting material so that light from the illumination unit 50 (see Fig. 4) can pass through. Specifically, the heater 60 has a transparent conductive film 62 made of, for example, an ITO (Indium Tin Oxide) film, and a pair of bus bars 64, 64 that supply power to the transparent conductive film 62. The transparent conductive film 62 is an example of the transparent conductive film of the present invention, and the bus bars 64 are an example of the electrodes of the present invention.

[0051] The transparent conductive film 62 is formed in a film shape on the lower surface 72C (the surface on the light diffusion section 80 side) of the transparent glass 72 by a film formation process such as vacuum deposition. The pair of bus bars 64 are formed in a strip or line shape by applying, for example, a conductive paste to the lower surface 72C of the transparent glass 72. When the heater 60 is controlled by the controller 27 (see FIG. 3 ) and power is supplied to the transparent conductive film 62 via the bus bars 64, the transparent conductive film 62 generates heat. This heats the transparent glass 72. The power supplied to the heater 60 is adjusted by the controller 27 to adjust the heat temperature of the transparent conductive film 62, thereby adjusting the temperature of the transparent glass 72, in other words, the temperature of the imaging device 100. The above-mentioned power adjustment by the controller 27 is performed based on an input signal from a temperature measurement unit (not shown) that measures the temperature of the stage 18.

[0052] While the inspection device 10 of the embodiment illustrates the heater 60 having the transparent conductive film 62 formed on the entire lower surface 72C of the transparent glass 72, the heater 60 is not limited to this. For example, a sheet-like or film-like heater may be used in which the transparent conductive film 62 and a pair of bus bars 64, 64 are formed on a substrate such as polyethylene terephthalate (PET), and this substrate is laminated with a transparent laminating material. Furthermore, in addition to the heater 60 that heats the imaging device 100, a cooling unit that cools the imaging device 100 may be provided. The cooling unit may be configured, for example, by forming a refrigerant flow path inside the transparent glass 72, or by having a refrigerant pipe in contact with the transparent glass 72.

[0053] As shown in Fig. 4, the light-transmitting section 70 has a light-antireflection section 90. The light-antireflection section 90 is disposed between the transparent glass 72 and the light-diffusing section 80. The light-antireflection section 90 is an example of a light-antireflection section of the present invention, and has the function of suppressing reflection of light irradiated from the illumination section 50 toward the wafer W by the light-transmitting section 70. This improves the light transmittance of the light-transmitting section 70.

[0054] The antireflection section 90 in this embodiment is, for example, an antireflection film 92 formed in a film-like shape on the lower surface 72C of the transparent glass 72 (the surface on the light diffusing section 80 side). The antireflection film 92 is an example of the antireflection film of the present invention and is formed by laminating it on the transparent conductive film 62 of the heater 60 using an AR (Anti-Reflection) coating. However, this lamination configuration is not limited to this, and the lamination configuration of the antireflection film 92 and the transparent conductive film 62 may be reversed. That is, the antireflection film 92 may be coated on the lower surface 72C of the transparent glass 72, and the transparent conductive film 62 may be coated on the antireflection film 92. Furthermore, the antireflection section 90 is not limited to the antireflection film 92. For example, the antireflection section 90 may be formed by disposing a sheet-like or film-like antireflection material having a moth-eye surface on the lower surface 72C of the transparent glass 72.

[0055] The light-transmitting section 70 configured as described above is supported on the LED substrate 54 of the illumination section 50 via a support member 94 provided on the edge portion 72B of the transparent glass 72, for example.

[0056] Next, an example of an inspection method for an imaging device 100 using the inspection apparatus 10 of the embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of an inspection method for an imaging device 100 using the inspection apparatus 10 of the embodiment. Note that the inspection method using the inspection apparatus 10 may inspect one imaging device 100 in a single inspection, or may inspect multiple imaging devices 100 in a single inspection.

[0057] First, a wafer placing step (S1) is executed. In the wafer placing step (S1), the wafer W is first removed from a container in the loader chamber 14 by a transfer unit and transferred to the prober chamber 12. Then, the wafer W is placed on the stage 18 so that the back surface of the imaging device 100 formed on the wafer W abuts against the upper surface 72A of the transparent glass 72. The wafer placing step (S1) corresponds to the wafer placing step of the present invention. Thereafter, the wafer W is fixed to the stage 18 by a fixing unit (not shown).

[0058] Next, the contacting step (S2) is performed. In the contacting step (S2), first, the stage 18 is moved horizontally, and also in the θ direction as necessary, until the electrode pads 118 of the imaging device 100 to be inspected are positioned below the probe needles 22. Then, the stage 18 is moved upward to bring the electrode pads 118 into contact with the probe needles 22. The contacting step (S2) corresponds to the contacting step of the present invention.

[0059] Next, the illumination step (S3) is performed. In the illumination step (S3), all LEDs 52 of the illumination unit 50 are turned on, and light is emitted from the illumination unit 50 toward the back surface of the imaging device 100. Here, the light from the LEDs 52 does not have a uniform light intensity distribution in a plane parallel to the wafer W immediately after emission from the LEDs 52. However, the light is diffused by passing through the light diffusion unit 80 and is emitted toward the wafer W. The light is then irradiated onto the back surface of the imaging device 100 via the light transmission unit 70 (arranged away from the illumination unit 50 toward the light transmission unit 70). As a result, the light from the LEDs 52 has a uniform light intensity distribution in a plane parallel to the wafer W when it is incident on the back surface of the imaging device 100. Therefore, according to the inspection apparatus 10 of the embodiment, by including the light diffusion unit 80 of this example, it is possible to irradiate the wafer W with light having a uniform light intensity distribution in the plane. The illumination step (S3) corresponds to the illumination step of the present invention.

[0060] Next, the inspection step (S4) is performed. In the inspection step (S4), the probe needles 22 are brought into contact with the electrode pads 118 of the imaging device 100 to be inspected, and the back surface of the imaging device 100 is irradiated with light (i.e., the contact step (S2) and the illumination step (S3) have been performed), and the electrical characteristics of the imaging device 100 are inspected. During this inspection, a temperature measurement unit (not shown) measures the temperature of the wafer W (actually, the temperature of the transparent glass 72), and based on the measurement result, the heater 60 is controlled to adjust the temperature of the wafer W to a desired value. In this way, the temperature of the imaging device 100 is adjusted to a temperature required for the inspection. Thereafter, the processes from the contact step (S2) onwards are repeated until inspection of all imaging devices 100 is completed.

[0061] The effects of the embodiment will be described below.

[0062] According to the inspection apparatus 10 of the embodiment, the stage 18 is composed of, in order from the side on which the wafer W is placed, a light-transmitting section 70, a light diffusion section 80, and an illumination section 50. In particular, the light diffusion section 80 in the embodiment is configured to be spaced apart from the light-transmitting section 70 toward the illumination section 50. That is, the light diffusion function is separated and independent from the light-transmitting section 70 (the light diffusion section 80 is independently disposed). Therefore, compared to a configuration in which the light-transmitting section 70 has a light diffusion function, it is possible to ensure a sufficient distance between the wafer W (i.e., the backside of the imaging device 100) and the light diffusion section 80. This increases the degree of freedom (design freedom) in the placement of the light diffusion section 80. This allows the distance from the illumination section 50 (LEDs 52) to be reduced or the distance from the wafer W to be increased, thereby improving the in-plane uniformity of the light intensity distribution of light irradiated onto the wafer W (imaging device 100). As a result, it is possible to improve the inspection accuracy of the back-illuminated imaging device 100.

[0063] Furthermore, according to the inspection device 10 of the embodiment, as described above, a configuration is adopted in which the light diffusion function is separated and independent from the light-transmitting section 70 (a configuration in which the light diffusion section 80 is independently disposed), and therefore the light diffusion section 80 can be separated from the heater 60 disposed in the light-transmitting section 70. This makes it possible to suppress deformation of the light diffusion section 80 due to the heat of the heater 60. Therefore, it is possible to prevent changes in the refractive index of light passing through the light diffusion section 80, and it is possible to stabilize the diffusion direction of the light diffusion section 80 without being affected by the heat of the heater 60. As a result, even in a configuration in which the heater 60 is provided in the light-transmitting section 70, it is possible to ensure in-plane uniformity of the light intensity distribution of light irradiated onto the wafer W.

[0064] Furthermore, according to the inspection device 10 of the embodiment, the above configuration allows the light diffusion section 80 to be disposed at a position where it is not affected by the heat from the heater 60, and therefore the light diffusion section 80 can be protected from the heat of the heater 60. Similarly, the light diffusion section 80 can be disposed at a position where it is not affected by the heat from the illumination section 50, and therefore the light diffusion section 80 can be protected from the heat of the illumination section 50.

[0065] Furthermore, according to the inspection device 10 of the embodiment, the heater 60 has a transparent conductive film 62 and a pair of bus bars 64, 64 for supplying power to the transparent conductive film 62, and a configuration is adopted in which the transparent conductive film 62 and the pair of bus bars 64, 64 are formed on the lower surface 72C of the transparent glass 72. This allows the heater 60 to be disposed in the light-transmitting section 70 without increasing the thickness of the light-transmitting section 70. This allows the light-transmitting section 70 to be made smaller.

[0066] 5, the transparent glass 72 is formed in a rectangular shape in a plan view, and a pair of bus bars 64, 64 are arranged parallel to and facing each other along two opposing edge portions 72B, 72B of the transparent glass 72, and the transparent conductive film 62 is formed in a rectangular shape in a plan view between the pair of bus bars 64, 64. That is, in the embodiment, a rectangular heater configured as described above is employed, so that heat generated within the surface of the transparent conductive film 62 is uniform, and the entire surface of the wafer W placed on the transparent glass 72 can be heated at a uniform temperature. As a result, the inspection device 10 of the embodiment can suppress variations in inspection results that occur for each imaging device 100 due to temperature differences, further improving the inspection accuracy of the imaging device 100.

[0067] Here, to explain the effect of the rectangular heater in this embodiment, the difference from a circular heater as a comparative example will be described in detail with reference to Fig. 7. Fig. 7 is a diagram for explaining the difference in effect between a circular heater and a rectangular heater. In Fig. 7, 7A is a plan view showing the schematic configuration of a circular heater 200, and 7B is a plan view showing the schematic configuration of a rectangular heater 60.

[0068] As shown in FIG. 7A , the circular heater 200 includes a pair of bus bars 202 arranged in a semicircular arc and a circular transparent conductive film 204 arranged between the pair of bus bars 202. The circular heater 200 is considered to be primarily made of a circular transparent glass plate. However, in the circular heater 200, the distance a between the pair of bus bars 202 (the distance in the opposing direction of the pair of bus bars 202) is not constant. In other words, the distance a varies depending on the position in the direction perpendicular to the opposing direction of the pair of bus bars 202, resulting in non-uniform temperature generation across the surface of the transparent conductive film 204. As a result, it is difficult to maintain a uniform temperature across the entire surface of the wafer W using the circular heater 200.

[0069] 7B, the distance b between the pair of bus bars 64, 64 (the distance in the opposing direction of the pair of bus bars 64, 64) is constant at any position, and therefore the temperature generated within the surface of the rectangular transparent conductive film 62 is uniform. As a result, the rectangular heater 60 makes it possible to adjust the entire surface of the wafer W to a uniform temperature.

[0070] Therefore, by being equipped with the rectangular heater 60 configured as described above, the inspection device 10 of the embodiment can stabilize the temperature distribution within the surface of the wafer W compared to the circular heater 200, thereby making it possible to further improve the inspection accuracy of the imaging device 100.

[0071] Furthermore, according to the inspection device 10 of the embodiment, a configuration is adopted in which the light-transmitting section 70 has an anti-reflection section 90 disposed between the transparent glass 72 and the light diffusing section 80. In particular, in the embodiment, as one preferred aspect, the anti-reflection section 90 is configured by an anti-reflection film 92 formed in a film form on the lower surface 72C of the transparent glass 72. This makes it possible to improve the light transmittance of light passing through the light-transmitting section 70 and to reduce the thickness and size of the light-transmitting section 70 of the stage 18. Furthermore, the number of LEDs 52 can be reduced, thereby saving space for installing the LEDs 52 and improving energy consumption.

[0072] Furthermore, the inspection apparatus 10 of the embodiment loads and unloads the wafer W using an upper surface transport mechanism that supports and transports the non-device formation region 120 of the wafer W. This eliminates the need to open holes in the transparent glass 72 for lift pins used to load and unload the wafer W, making the light transmittance of the transparent glass 72 constant, and as a result, the inspection accuracy of the wafer W is further improved.

[0073] Although the embodiments of the present invention have been described above, the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the spirit of the present invention. Some modifications are shown below.

[0074] [Variation 1] In the above embodiment, the transparent glass 72 on which the wafer W is placed is exemplified as being rectangular in plan view, but the shape of the transparent glass 72 is not limited to this and may be circular in plan view.

[0075] [Variation 2] In the above embodiment, transparent glass 72 was used as an example of a flat light-transmitting member that constitutes the light-transmitting section 70, but this is not limiting, and a transparent plastic plate such as acrylic or vinyl chloride may be used instead of the transparent glass 72. [Explanation of symbols]

[0076] W...wafer, 10...inspection equipment, 12...prober room, 14...loader room, 16...tester, 18...stage, 20...probe card, 22...probe needle, 24...interface, 26...controller, 27...controller (prober CPU), 28...wiring, 30...wiring, 32...computer, 34...display unit, 38...wiring, 40...operation unit, 42...display panel, 50...lighting unit, 52...LED, 54...LED board, 56...heat sink, 60...heater , 62...transparent conductive film, 64...bus bar (electrode), 70...light-transmitting portion, 72...transparent glass, 80...light diffusing portion, 82...sheet, 90...light-antireflection portion, 92...light-antireflection film, 100...imaging device, 102...photodiode, 104...wiring, 106...wiring layer, 108...lens, 110...filter, 112...red color filter, 114...blue color filter, 116...green color filter, 118...electrode pad, 120...non-device-forming area

Claims

1. A stage on which an irradiation object is placed, a light-transmitting portion that constitutes a mounting surface of the irradiation object and has light transmittance; an illumination unit disposed on the opposite side of the light-transmitting unit from the side of the object to be illuminated, and emitting light toward the light-transmitting unit; a light diffusion section that is disposed between the light transmitting section and the illumination section and spaced apart from the light transmitting section toward the illumination section, and that diffuses and transmits light from the illumination section; A stage equipped with:

2. the light-transmitting portion includes a heater; The stage of claim 1 .

3. The heater includes a transparent conductive film, a pair of electrodes for supplying power to the transparent conductive film, and and the transparent conductive film and the pair of electrodes are formed on a surface of the light-transmitting section facing the light diffusion section; The stage of claim 2 .

4. The light-transmitting portion is formed in a rectangular shape in a plan view, the pair of electrodes are arranged parallel to and facing each other along two opposing edges of the light-transmitting portion, the transparent conductive film is formed between the pair of electrodes in a rectangular shape in a plan view; The stage of claim 3 .

5. the light-transmitting section has a light reflection preventing section that suppresses reflection of light irradiated from the illumination section toward the illumination target; A stage according to any one of claims 1 to 4.

6. the light-antireflection portion is a light-antireflection film formed in a film-like shape on a surface of the light-transmitting portion on the side of the light-diffusing portion, 6. The stage of claim 5.

7. A light irradiation method performed on a stage on which an irradiation object is placed, a light emitting step of emitting light from an illumination unit; a light diffusing step of diffusing the light emitted from the illumination unit through a light diffusing unit while transmitting the light; an irradiation step of irradiating the light diffused by the light diffusion unit onto the irradiation target via a light transmitting unit provided at a position away from the light diffusion unit; A light irradiation method comprising:

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