Defect evaluation device

Abstract

The present invention provides a defect removal evaluation device, which reduces the influence of a chuck table for sucking and holding a wafer on the evaluation of defect removal. The defect removal evaluation device includes: a defect removal judgment unit, which has a laser beam irradiation unit for irradiating a laser beam to the wafer and a transmission and reception unit for irradiating microwaves to the wafer and receiving reflected waves of the microwaves reflected by the wafer, the defect removal judgment unit judges whether a defect removal layer including grinding strain generated by grinding the wafer has defect removal properties; and a chuck table for holding the wafer with a holding surface. The chuck table has: a conductive non-metallic porous component, which constitutes a holding surface and has the property of reflecting or absorbing microwaves; and a base component, which has a negative pressure transmission path for transmitting negative pressure to the non-metallic porous component.

Description

Technical Field

[0001] The present invention relates to a gettering performance evaluation device. Background Art

[0002] In recent years, in order to miniaturize and lighten device chips, the wafers after device formation have been processed to be thinner. However, for example, when the wafer is polished and thinned to less than 100 μm, the gettering property that suppresses the activity of metal elements that are harmful to the device may be reduced, resulting in malfunction of the device. In order to solve this problem, the following method has been proposed: a gettering layer that captures metal elements is formed in the wafer, the wafer is irradiated with excitation light and microwaves to generate excess carriers, and the gettering performance (hereinafter referred to as gettering property) of the gettering layer is evaluated based on the decay time of the reflected microwaves (see Patent Documents 1 and 2).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-012594

[0004] Patent Document 2: Japanese Patent Application Publication No. 2016-012595

[0005] When evaluating the defect removal performance of a wafer by the above-mentioned conventional method, a chuck table is formed by joining a component formed by a porous material such as alumina ceramics to a metal base formed by a metal such as stainless steel and engraved with a groove that serves as an exhaust flow path, and the wafer to be evaluated for defect removal performance is adsorbed and held by the holding surface of the chuck table. Here, alumina ceramics have the property of transmitting microwaves, and on the other hand, metals have the property of reflecting microwaves. Therefore, when the wafer is adsorbed and held by the above-mentioned chuck table and irradiated with microwaves, the microwaves pass through the wafer and the porous material and are reflected by the metal base. Grooves that serve as exhaust flow paths are engraved on the metal base. In addition, according to the Friis transmission formula, when the transmission distance becomes larger, the transmission intensity of the microwaves attenuates inversely proportional to the square of the transmission distance. Therefore, the intensity of the microwaves reaching the receiver changes according to the unevenness of the grooves of the exhaust flow path of the metal base.

[0006] There is no problem when the defect removeability of the chip is evaluated at the same coordinate (i.e., the same point) each time. However, when the defect removeability of the chip is evaluated on the entire surface of the chip or at multiple locations, there is a problem that the evaluation results of the defect removeability depend on the shape of the metal base at each point and cannot be compared and evaluated. Summary of the invention

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a gettering performance evaluation device that reduces the influence of a chuck stage that suction-holds a wafer on the gettering performance evaluation.

[0008] According to one aspect of the present invention, there is provided a defect removal evaluation device, which comprises: a defect removal judgment unit, which comprises a laser beam irradiation unit for irradiating a laser beam to a wafer and a transmitting and receiving unit for irradiating microwaves to the wafer and receiving microwaves reflected by the wafer, the defect removal judgment unit judging whether a defect removal layer including grinding strain generated by grinding the wafer has defect removal properties; and a chuck table for holding the wafer by a holding surface, the chuck table comprising: a conductive non-metallic porous component constituting the holding surface and having a property of reflecting or absorbing the microwaves; and a base component exposing the holding surface and surrounding the non-metallic porous component, and having a negative pressure transmission path for transmitting negative pressure to the non-metallic porous component.

[0009] Preferably, the non-metallic porous component is made of a material having a sum of a reflectivity of the microwave and absorptivity of the microwave of 80% or more.

[0010] In addition, it is preferred that the non-metallic porous member contains porous SiC or porous carbon.

[0011] According to another aspect of the present invention, there is provided a defect removal property evaluation device, which includes: a defect removal determination unit, which includes a laser beam irradiation unit for irradiating a laser beam to a wafer and a transmission and reception unit for irradiating a microwave to the wafer and receiving the microwave reflected by the wafer, the defect removal determination unit determines whether a defect removal layer including a grinding strain generated by grinding the wafer has defect removal property; and a chuck worktable, which holds the wafer by a holding surface, the chuck worktable comprising: a porous member constituting the holding surface and being permeable to the microwave; a base member having a negative pressure transmission path for transmitting negative pressure to the porous member; a supporting member, which is made of a material permeable to the microwave, is arranged at a position lower than the porous member, supports the porous member, and has a transmission path for transmitting the negative pressure from the negative pressure transmission path to the porous member; and a reflecting plate, which is arranged at a position lower than the supporting member, is made of a conductive material that reflects the microwave, and has a flat surface.

[0012] Preferably, the reflective plate comprises any material selected from the group consisting of stainless steel, iron, an alloy containing iron, aluminum, an alloy containing aluminum, copper, an alloy containing copper, titanium, and carbon fiber reinforced plastic.

[0013] According to another aspect of the present invention, there is provided a defect removal property evaluation device, which comprises: a defect removal determination unit, which comprises a laser beam irradiation unit for irradiating a laser beam to a wafer and a transmitting and receiving unit for irradiating a microwave to the wafer and receiving the microwave reflected by the wafer, the defect removal determination unit determining whether a defect removal layer including a grinding strain generated by grinding the wafer has defect removal property; and a chuck table for holding the wafer by a holding surface, the chuck table comprising: a porous member constituting the holding surface and being permeable to the microwave; a base member having a negative pressure transmission path for transmitting negative pressure to the porous member; a supporting member, which is made of a material permeable to the microwave, is arranged at a position lower than the porous member, supports the porous member, and has a transmission path for transmitting the negative pressure from the negative pressure transmission path to the porous member; and a radio wave absorber, which is arranged at a position lower than the supporting member and is made of a material that absorbs the microwave.

[0014] Preferably, the radio wave absorber includes any of a magnetic radio wave absorber, a dielectric radio wave absorber, a conductive radio wave absorber, and a λ / 4 type radio wave absorber.

[0015] The present invention can reduce the influence of a chuck table for sucking and holding a wafer on the evaluation of gettering performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a perspective view showing a wafer to be evaluated by the gettering property evaluation apparatus according to the first embodiment.

[0017] Figure 2 It is a perspective view of a configuration example of the gettering property evaluation device according to the first embodiment.

[0018] Figure 3 yes Figure 2 Cross-sectional view along line III-III.

[0019] Figure 4 yes Figure 2 A three-dimensional view of a base component of a gettering evaluation device.

[0020] Figure 5 It is a cross-sectional view of a gettering property evaluation device according to a modification example (first modification example) of the first embodiment.

[0021] Figure 6 It is a cross-sectional view of a configuration example of a gettering performance evaluation device according to a second embodiment.

[0022] Figure 7 yes Figure 6 A three-dimensional view of a supporting component of a gettering performance evaluation device.

[0023] Figure 8 yes Figure 6A three-dimensional view of a base component of a gettering evaluation device.

[0024] Fig. 9 It is a cross-sectional view of a gettering property evaluation device according to a modification example (second modification example) of the second embodiment.

[0025] Fig.10 It is a cross-sectional view of a configuration example of a gettering property evaluation device according to a third embodiment.

[0026] Fig.11 It is a perspective view of a configuration example of a grinding and polishing device according to a fourth embodiment.

[0027] Fig.12 It is a graph showing the intensity distribution of reflected waves of microwaves received by the gettering property evaluation apparatuses of the example and the comparative example.

[0028] Description of symbols

[0029] 1, 1-2, 1-3, 1-4, 1-5: defect removal evaluation device (device for measuring material properties); 10: defect removal judgment unit; 11: laser beam irradiation unit; 12: sending and receiving unit; 20, 20-2, 50, 50-2, 50-3: chuck worktable; 21: non-metallic porous component; 22, 22-2: base component; 24, 56: holding surface; 28, 28-2, 65, 65-2: negative pressure transmission path; 51: porous component; 52, 52-2: base component; 53, 53-2: supporting component; 54: reflecting plate; 66, 66-2: transmission path; 74: radio wave absorber; 100: wafer; 110: defect removal layer. DETAILED DESCRIPTION

[0030] The mode (embodiment) for implementing the present invention is described in detail with reference to the accompanying drawings. The present invention is not limited to the contents described in the following embodiments. In addition, the structural elements described below include substantially the same structural elements that can be easily thought of by those skilled in the art. In addition, the structures described below can be appropriately combined. In addition, various omissions, substitutions or changes in the structure can be made within the scope of the gist of the present invention.

[0031] [First embodiment]

[0032] A gettering property evaluation device 1 according to a first embodiment of the present invention will be described with reference to the drawings. Figure 1 1 is a perspective view showing a wafer 100 to be evaluated by the gettering property evaluation apparatus 1 according to the first embodiment. Figure 2 It is a perspective view of a configuration example of the gettering property evaluation device 1 according to the first embodiment. Figure 3 yes Figure 2 Cross-sectional view along line III-III. Figure 4 yes Figure 2 1 is a perspective view of a base member 22 of the gettering property evaluation device 1.

[0033] The defect removal performance evaluation device 1 of the first embodiment is a device that measures and evaluates the defect removal performance (hereinafter referred to as the defect removal performance) of the defect removal layer 110 formed in the wafer 100. Here, the defect removal layer 110 is a layer that captures metal elements. In addition, in the first embodiment, the defect removal performance evaluation device 1 measures and evaluates the defect removal performance of a plurality of different specified positions 120 of the defect removal layer 110 formed in the wafer 100, but in the present invention, the defect removal performance evaluation device 1 may also comprehensively measure the defect removal layer 110 formed in the wafer 100 at specified intervals to measure and evaluate the defect removal performance of the entire surface. The wafer 100 that is the evaluation object of the defect removal performance evaluation device 1 of the first embodiment is a disk-shaped semiconductor wafer or an optical device wafer using silicon, sapphire, gallium arsenide, or the like as a base material. As Figure 1 As shown, on the front side 101 of the wafer 100 , devices 103 are formed in regions partitioned by a plurality of planned dividing lines 102 formed in a grid pattern.

[0034] After the wafer 100 is thinned to a predetermined thickness by grinding the back surface 104 on the opposite side of the front surface 101, a gettering layer 110 is formed inside the wafer 100, and the gettering property of the gettering layer 110 is evaluated by the gettering property evaluation device 1. The gettering property of the gettering layer 110 refers to the magnitude of the effect of suppressing the activity of metal elements such as copper that are harmful to the device 103. The device 103 formed on the front surface 101 of the wafer 100 is, for example, a memory (a memory such as a flash memory or a DRAM (Dynamic Random Access Memory)), and it is undesirable to be contaminated by metal (such as copper elements) from the back surface 104.

[0035] In addition, in the first embodiment, the gettering layer 110 of the wafer 100 includes grinding strain generated by grinding the back surface 104 of the wafer 100. In the present invention, the gettering layer 110 is not limited to being formed by grinding, and may be formed by other processes such as dry grinding, wet chemical mechanical polishing (CMP) using a liquid chemical containing no abrasive, plasma etching, laser beam irradiation, and ion beam irradiation.

[0036] like Figure 2 and Figure 3 As shown, the gettering property evaluation apparatus 1 of the first embodiment includes a gettering determination unit 10, a chuck table 20, a moving unit (moving mechanism) 30, and a control unit 40 that controls the respective units.

[0037] like Figure 2 and Figure 3 As shown, the gettering determination unit 10 is a unit that determines whether the gettering layer 110 has a gettering property of a specified value at any specified position 120 among multiple specified positions 120 for evaluating the gettering property. The gettering determination unit 10 includes a laser beam irradiation unit 11, a transmitting and receiving unit 12, and a determination unit 13.

[0038] The laser beam irradiation unit 11 irradiates the laser beam 15 to the predetermined position 120 of the wafer 100 on the chuck table 20, excites the gettered layer 110 at the predetermined position 120 to generate excess carriers, and increases the reflectivity of the microwave 17 irradiated from the transmitting and receiving unit 12. In the first embodiment, the laser beam 15 irradiated by the laser beam irradiation unit 11 is, for example, in a pulse shape and has a predetermined wavelength, thereby becoming the excitation light of the gettered layer 110. In the first embodiment, the predetermined wavelength of the laser beam 15 irradiated by the laser beam irradiation unit 11 is, for example, 904 nm, 532 nm, 349 nm, etc.

[0039] The getter determination unit 10 starts irradiating the microwave 17 to the predetermined position 120 through the transmitting and receiving unit 12, and then starts irradiating the laser beam 15 to the predetermined position 120 irradiated with the microwave 17 through the laser beam irradiation unit 11. Then, the getter determination unit 10 stops irradiating the laser beam 15 by the laser beam irradiation unit 11, and stops irradiating the microwave 17 by the transmitting and receiving unit 12 after a certain time has passed since the irradiation of the laser beam 15 was stopped. During the irradiation of the microwave 17, the transmitting and receiving unit 12 receives the reflected wave 18 of the microwave reflected by the getter layer 110 at the predetermined position 120 or reflected by the chuck table 20 after passing through the getter layer 110 at the predetermined position 120. During the irradiation of the laser beam 15, the reflectivity of the microwave 17 increases with the generation of excess carriers, thereby increasing the intensity of the reflected wave 18 of the microwave received by the transmitting and receiving unit 12. After the irradiation of the laser beam 15 is stopped, the reflectivity of the microwave 17 gradually decreases with the recombination of carriers, thereby gradually attenuating the intensity of the reflected wave 18 of the microwave received by the transmitting and receiving unit 12. In the first embodiment, the frequency of the microwave 17 irradiated by the transmitting and receiving unit 12 is 25 GHz, but the present invention is not limited to this.

[0040] The determination unit 13 obtains information on the reflected wave 18 of the microwave received by the transmitting and receiving unit 12, and uses the μ-PCD method (Photo Conductivity Decay) to quantify the elements of captured metal elements based on the decay time of the reflected wave 18 of the microwave, thereby evaluating the defect removal property of the defect removal layer 110 at a specified position 120, and comparing it with a pre-set specified value to determine whether it has the defect removal property of the specified value.

[0041] like Figure 2 and Figure 3 As shown, the chuck worktable 20 has a non-metallic porous component 21, a base component 22 and a mounting table 23. The non-metallic porous component 21 has a plurality of holes, and forms a flat holding surface 24 along a horizontal plane. The non-metallic porous component 21 has the property of reflecting or absorbing microwaves. In addition, the non-metallic porous component 21 has electrical conductivity and is made of a non-metallic material.

[0042] Here, the property of reflecting or absorbing microwaves means that the sum of the reflectivity of microwaves and the absorptivity of microwaves is 80% or more. That is, the sum of the reflectivity of microwaves and the absorptivity of microwaves of the non-metallic porous component 21 is 80% or more. Preferably, the sum of the reflectivity of microwaves and the absorptivity of microwaves of the non-metallic porous component 21 is 90% or more, more preferably 95% or more.

[0043] In addition, the reflectivity of microwaves is the ratio of the beam of microwaves reflected waves to the beam of microwaves before reflection. In addition, the absorptivity of microwaves is the ratio of the beam of microwaves absorbed to the beam of microwaves before absorption. In addition, the transmittance of microwaves is the ratio of the beam of microwaves transmitted waves to the beam of microwaves before transmission.

[0044] In addition, conductivity means that the conductivity is 1×10 -6 S / m or more. That is, the electrical conductivity of the non-metallic porous component 21 is 1×10 -6 S / m or more. The conductivity of the non-metallic porous component 21 is preferably 1×10 -5 Since the non-metallic porous member 21 has such high conductivity, it appropriately has the property of reflecting or absorbing microwaves as described above.

[0045] In addition, being made of non-metallic material means being made of material whose content ratio of metal element in monomer state is 1 mass % or less. That is, the non-metallic porous component 21 is made of material whose content ratio of metal element in monomer state is 1 mass % or less. In this way, since the content ratio of metal element in monomer state of the non-metallic porous component 21 is low, the contamination of the metal element in monomer state from the holding surface 24 to the wafer 100 is appropriately suppressed.

[0046] The non-metallic porous component 21 comprises porous SiC or porous carbon. The non-metallic porous component 21 can be made of porous SiC, or porous carbon, or porous SiC and porous carbon, or can comprise the same non-metallic material with the property of reflecting or absorbing microwaves and conductivity as porous SiC and porous carbon. In addition, porous SiC and porous carbon can also comprise an appropriate amount of sintering aid.

[0047] The porous SiC has a plurality of pores and is generally composed of SiC (silicon carbide). For example, the electrical conductivity of the non-metallic porous component 21 including the porous SiC is about 1×10 -5 The nonmetallic porous component 21 of the present invention is characterized in that: the nonmetallic porous component 21 has a 25 GHz microwave reflectivity of 47%, a 25 GHz microwave absorptivity of 53%, and a 25 GHz microwave transmittance of 0.2%. The sum of the reflectivity and absorptivity of the nonmetallic porous component 21 to a microwave of 25 GHz is about 100%. In addition, the thickness of the nonmetallic porous component 21 comprising porous SiC is not limited to 3mm. In addition, the nonmetallic porous component 21 comprising porous SiC varies according to thickness and temperature etc. to the reflectivity, absorptivity and transmittance of microwaves.

[0048] The porous carbon has a plurality of pores and is generally composed of carbon. For example, the electrical conductivity of the non-metallic porous member 21 including the porous carbon is about 1×10 -4 The non-metallic porous component 21 has a 25 GHz microwave reflectivity of about 99.8%, a microwave absorptivity of about 0.2%, and a microwave transmittance of about 0%. The sum of the reflectivity and absorptivity of the non-metallic porous component 21 to a microwave frequency of 25 GHz is about 100%. In addition, the thickness of the non-metallic porous component 21 comprising porous carbon is not limited to 3 mm. In addition, the non-metallic porous component 21 comprising porous carbon varies in reflectivity, absorptivity and transmittance of microwaves according to thickness and temperature.

[0049] The base member 22 is fixed on the mounting table 23. Figure 4 As shown, the base member 22 has a porous member embedding portion 25 formed on the inner circumference of a circular recess 22-1 formed in the center of the upper surface. The base member 22 embeds and fixes the non-metallic porous member 21 in the porous member embedding portion 25 so that the holding surface 24 is exposed and surrounds the non-metallic porous member 21.

[0050] like Figure 4As shown, in the base member 22, a suction path 26 and a groove 27 for an exhaust flow path are formed on the bottom surface of a circular depression 22-1 at the lower side of the porous member embedding portion 25. Both the suction path 26 and the groove 27 for the exhaust flow path are formed with depressions and projections on the bottom surface of the circular depression 22-1 of the base member 22. The suction path 26 penetrates the central part of the base member 22 in the up-down direction from the bottom surface of the depression 22-1, and is connected to the suction source 29 via a through hole formed in the central part of the mounting table 23. The groove 27 for the exhaust flow path includes grooves 27-1, 27-2, and 27-3 formed in concentric circles with each other, and four grooves 27-4 that connect the grooves 27-1, 27-2, and 27-3 in the radial direction. The suction path 26 and the groove 27 of the exhaust flow path are connected to each other on the bottom surface of the circular depression 22-1, forming a negative pressure transmission path 28 for transmitting the negative pressure from the suction source 29 to the lower surface of the non-metallic porous component 21. The negative pressure transmitted to the lower surface of the non-metallic porous component 21 by the negative pressure transmission path 28 is transmitted to the holding surface 24 via the multiple holes in the non-metallic porous component 21.

[0051] In this way, the chuck worktable 20 utilizes the negative pressure transmitted to the holding surface 24 by the negative pressure transmission path 28 through the multiple holes in the non-metallic porous component 21, and uses the holding surface 24 to attract and hold the front side 101 of the chip 100 from the bottom, so that the back side 104 of the chip 100 is exposed to the upper side.

[0052] like Figure 2 and Figure 3 As shown, the moving unit 30 is connected to the gettering determination unit 10. The moving unit 30 moves the gettering determination unit 10 relative to the wafer 100 on the chuck table 20, thereby moving the irradiation position of the laser beam 15 of the laser beam irradiation unit 11 and the irradiation position of the microwave 17 of the transmitting and receiving unit 12, and moving the predetermined position 120 for evaluating the gettering property.

[0053] The control unit 40 controls the above-mentioned components constituting the gettering performance evaluation apparatus 1. That is, the control unit 40 causes the gettering performance evaluation apparatus 1 to evaluate the gettering performance of the wafer 100. The control unit 40 switches the opening and closing of the on-off valve between the negative pressure transmission path 28 and the suction source 29.

[0054] In the first embodiment, the determination unit 13 and the control unit 40 are a computer capable of executing a computer program. The determination unit 13 and the control unit 40 include: a processing unit having a microprocessor such as a CPU (Central Processing Unit); a storage device having a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory); and an input / output interface device. The processing unit executes the computer program stored in the storage device and generates a control signal for controlling the defect removal evaluation device 1. The processing unit outputs the generated control signal to each component of the defect removal evaluation device 1 via the input / output interface device.

[0055] In the first embodiment, the functions of the determination unit 13 and the control unit 40 are implemented by the arithmetic processing device executing a computer program stored in the storage device. In the present invention, the determination unit 13 and the control unit 40 are not limited thereto, and may be implemented by separate computer systems, for example.

[0056] The operation of the gettering performance evaluation device 1 of the first embodiment having the above-described structure will be described below. The gettering performance evaluation device 1 positions the position 120 for evaluating gettering performance at any one of a plurality of predetermined positions 120, and irradiates the microwave 17 to the wafer 100 held by the holding surface 24 of the chuck table 20 through the transmitting and receiving unit 12. The gettering performance evaluation device 1 irradiates the laser beam 15 for a certain period of time through the laser beam irradiation unit 11 in a state where the microwave 17 is irradiated through the transmitting and receiving unit 12, thereby exciting the gettering layer 110 to generate excess carriers, and then stops irradiating the laser beam 15 through the laser beam irradiation unit 11. While the microwave 17 is irradiated through the transmitting and receiving unit 12, the gettering performance evaluation device 1 receives through the transmitting and receiving unit 12 the reflected wave 18 of the microwave reflected by the gettering layer 110 where the excess carriers are generated, or the reflected wave 18 of the microwave reflected by the chuck table 20 after the microwave 17 passes through the excited gettering layer 110. The gettering property evaluation device 1 evaluates the gettering property of the gettering layer 110 at any one of the predetermined positions 120 located above by the determination unit 13 based on the decay time of the reflected wave 18 of the microwave received by the transmitting and receiving unit 12 .

[0057] Then, the gettering performance evaluation device 1 moves the gettering judgment unit 10 relative to the wafer 100 on the chuck table 20 by means of the moving unit 30, thereby positioning the position 120 for evaluating the gettering performance at the next position among the plurality of prescribed positions 120, and, as before, performs the evaluation of the gettering performance of the gettering layer 110. In this way, the gettering performance evaluation device 1 sequentially positions the plurality of prescribed positions 120 one by one, and performs the evaluation of the gettering performance of the gettering layer 110.

[0058] In the gettering performance evaluation device 1 of the first embodiment, the chuck table 20 has a conductive non-metallic porous member 21, which constitutes a holding surface 24 and has a property of reflecting or absorbing microwaves. Therefore, in the gettering performance evaluation device 1 of the first embodiment, more than 80% of the light beam of the microwave 17 irradiated by the transmitting and receiving unit 12 is reflected or absorbed by the flat holding surface 24 of the non-metallic porous member 21, and the reflected part becomes a part of the reflected wave 18 of the microwave and is received by the transmitting and receiving unit 12, so it does not reach the unevenness of the base member 22. In addition, in the gettering performance evaluation device 1 of the first embodiment, the component that is reflected by the flat holding surface 24 of the non-metallic porous member 21 and becomes a part of the reflected wave 18 of the microwave becomes a DC (Direct Current) component in the measurement signal processed by the transmitting and receiving unit 12 and the determination unit 13, so the determination unit 13 can easily remove this component from the measurement signal. Therefore, in the first embodiment of the defect removal performance evaluation device 1, when the specified position 120 is moved, the possibility that the intensity of the reflected wave 18 of the microwave will change due to the unevenness of the base member 22 can be reduced, that is, the intensity of the reflected wave 18 of the microwave can be made uniform regardless of the specified position 120, thereby achieving the following effect: the influence of the chuck worktable 20 that attracts and holds the chip 100 on the defect removal performance evaluation can be reduced.

[0059] In the gettering performance evaluation device 1 of the first embodiment, the non-metallic porous component 21 includes porous SiC or porous carbon. Therefore, the gettering performance evaluation device 1 of the first embodiment can utilize the flat holding surface 24 of the non-metallic porous component 21 to reflect or absorb a higher proportion of the light beam of the microwave 17, so when the predetermined position 120 is moved, the following effects are achieved: the possibility that the intensity of the reflected wave 18 of the microwave will change due to the unevenness of the base component 22 can be reliably reduced, thereby reliably reducing the influence of the chuck table 20 that attracts and holds the wafer 100 on the evaluation of the gettering performance.

[0060] [First variant]

[0061] A gettering property evaluation device 1 - 2 according to a modification example (first modification example) of the first embodiment of the present invention will be described with reference to the drawings. Figure 5FIG. 1 is a cross-sectional view of a gettering performance evaluation device 1-2 according to a first variant. Figure 5 In the present invention, the same parts as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

[0062] like Figure 5 As shown, the defect removal performance evaluation device 1-2 of the first modified example is a device obtained by changing the chuck table 20 to a chuck table 20-2 in the defect removal performance evaluation device 1 of the first embodiment. The chuck table 20-2 is a member obtained by changing the base member 22 having the negative pressure transmission path 28 composed of the suction path 26 and the groove 27 of the exhaust flow path in the chuck table 20 to a base member 22-2 having the negative pressure transmission path 28-2 composed of the suction path 26 and a plurality of through holes 27-5. The plurality of through holes 27-5 penetrate the base member 22-2 in the up-down direction and communicate with the suction path 26 on the bottom surface of the circular recess 22-1. Both the suction path 26 and the plurality of through holes 27-5 form concavities and convexities on the bottom surface of the circular recess 22-1 of the base member 22-2.

[0063] The gettering performance evaluation device 1-2 of the first modified example is obtained by replacing the groove 27 of the exhaust flow path constituting the negative pressure transmission path 28 in the gettering performance evaluation device 1 of the first embodiment with a plurality of through holes 27-5 constituting the negative pressure transmission path 28-2. Therefore, the gettering performance evaluation device 1-2 of the first modified example has the same function and effect as the gettering performance evaluation device 1 of the first embodiment.

[0064] [Second embodiment]

[0065] A gettering property evaluation device 1 - 3 according to a second embodiment of the present invention will be described with reference to the drawings. Figure 6 It is a perspective view of a configuration example of a gettering property evaluation device 1 - 3 according to the second embodiment. Figure 7 yes Figure 6 A perspective view of a supporting member 53 of the gettering performance evaluation device 1-3. Figure 8 yes Figure 6 A three-dimensional view of the base member 52 of the defect removal evaluation device 1-3. Figures 6 to 8 In the present invention, the same parts as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

[0066] like Figure 6 As shown, the gettering performance evaluation device 1-3 of the second embodiment is a device obtained by replacing the chuck table 20 with a chuck table 50 in the gettering performance evaluation device 1 of the first embodiment. Figure 6 As shown, the chuck table 50 includes a porous member 51 , a base member 52 , a support member 53 , a reflection plate 54 , and a mounting table 55 .

[0067] The porous member 51 forms a holding surface 56 which is the same as the holding surface 24 and is permeable to microwaves. Here, being permeable to microwaves means that the transmittance of microwaves is 80% or more. That is, the transmittance of microwaves of the porous member 51 is 80% or more. Preferably, the transmittance of microwaves of the porous member 51 is 90% or more, and more preferably 95% or more.

[0068] In addition, the porous component 51 has no electrical conductivity, that is, the electrical conductivity is less than 1×10 -6 S / m. That is, the conductivity of the porous component 51 is less than 1×10 -6 S / m. The conductivity of the porous component 51 is preferably less than 1×10 -10 Since the porous member 51 has such a low conductivity, it has appropriate permeability to microwaves as described above. In addition, like the non-metallic porous member 21, the porous member 51 is made of a non-metallic material.

[0069] The porous member 51 includes porous alumina ceramics. The porous member 51 may be composed of porous alumina ceramics, or may include a material that is permeable to microwaves and non-conductive like porous alumina ceramics. In addition, the porous alumina ceramics may also include an appropriate amount of sintering aid.

[0070] The porous alumina ceramic has a plurality of pores and is generally composed of alumina ceramic. For example, the conductivity of the porous component 51 including the porous alumina ceramic is less than 1×10 -14 S / m, thickness is 3mm. The transmittance of the porous component 51 to microwaves with a frequency of 25GHz is about 100%, the reflectivity to microwaves with a frequency of 25GHz is about 0%, and the absorptivity to microwaves with a frequency of 25GHz is about 0%. The sum of the reflectivity and absorptivity of the porous component 51 to microwaves with a frequency of 25GHz is about 0%. In addition, the thickness of the porous component 51 comprising porous alumina ceramic is not limited to 3mm. The transmittance of the porous component 51 to microwaves with a frequency of 25GHz is almost 100% regardless of thickness and temperature.

[0071] The base member 52 is fixed on the mounting table 55. Figure 6 As shown, the base member 52 holds the support member 53 by the inner circumference of the circular recess 52-1 formed in the center of the upper surface. In the base member 52, a space for disposing the reflection plate 54 is formed below the position where the support member 53 is held. The base member 52 holds the support member 53 by the inner circumference of the circular recess 52-1, and supports the porous member 51 on the support member 53, so that the holding surface 56 is exposed and surrounds the porous member 51.

[0072] In the base member 52, as Figure 8As shown, a suction path 61 and a groove 62 of an exhaust flow path are formed on the bottom surface of the circular recess 52-1. Both the suction path 61 and the groove 62 of the exhaust flow path are formed with projections and depressions on the bottom surface of the circular recess 52-1 of the base member 52. The suction path 61 passes through the central portion of the base member 52 in the up-down direction from the bottom surface of the recess 52-1, and is connected to the suction source 59 via a through hole formed in the central portion of the mounting table 55. The groove 62 of the exhaust flow path has a groove 62-1 formed in a circular shape on the outer periphery and a groove 62-2 connecting the groove 62-1 in the radial direction. The suction path 61 and the groove 62 of the exhaust flow path are connected to each other on the bottom surface of the circular recess 52-1, forming a negative pressure transmission path 65 that transmits the negative pressure from the suction source 59 to the lower surface of the support member 53.

[0073] like Figure 6 As shown, the support member 53 is disposed below the porous member 51, and supports the porous member 51 with its upper surface 53-1. Like the porous member 51, the support member 53 is made of a material that is transparent to microwaves.

[0074] The support member 53 includes at least one of alumina ceramic and polyacetal. The support member 53 may be made of alumina ceramic, polyacetal, alumina ceramic and polyacetal, or may include a material that is permeable to microwaves and non-conductive like alumina ceramic and polyacetal. In addition, alumina ceramic or polyacetal may also include an appropriate amount of sintering aid or additive.

[0075] For example, the electrical conductivity of the support member 53 including alumina ceramic is less than 1×10 -14 S / m, and a thickness of 10 mm. The transmittance of the support member 53 to microwaves with a frequency of 25 GHz is approximately 100%, the reflectance to microwaves with a frequency of 25 GHz is approximately 0%, and the absorptivity to microwaves with a frequency of 25 GHz is approximately 0%. The sum of the reflectance and absorptivity of the support member 53 to microwaves with a frequency of 25 GHz is approximately 0%. In addition, the thickness of the support member 53 made of alumina ceramic is not limited to 10 mm. The transmittance of the support member 53 to microwaves with a frequency of 25 GHz is approximately 100%, which is almost independent of thickness and temperature.

[0076] In addition, for example, the electrical conductivity of the support member 53 made of polyacetal is less than 1×10 -14S / m, and a thickness of 10 mm. The transmittance of the support member 53 to microwaves with a frequency of 25 GHz is about 100%, the reflectance to microwaves with a frequency of 25 GHz is about 0%, and the absorptivity to microwaves with a frequency of 25 GHz is about 0%. The sum of the reflectance and absorptivity of the support member 53 to microwaves with a frequency of 25 GHz is about 0%. In addition, the thickness of the support member 53 made of polyacetal is not limited to 10 mm. The transmittance of the support member 53 to microwaves with a frequency of 25 GHz is almost 100% regardless of thickness, temperature, etc.

[0077] like Figure 7 As shown, the support member 53 is formed with a suction path 63 and a groove 64 of the exhaust flow path on the upper surface 53-1. The suction path 63 and the groove 64 of the exhaust flow path are both formed with projections and depressions on the upper surface 53-1 of the support member 53. The suction path 63 is formed to penetrate the central part of the support member 53 in the up-down direction, and is connected to the suction source 59 via the negative pressure transmission path 65 and the through hole formed in the central part of the mounting table 55. The groove 64 of the exhaust flow path has grooves 64-1, 64-2, and 64-3 formed in concentric circles with each other and four grooves 64-4 that connect the grooves 64-1, 64-2, and 64-3 in the radial direction. The suction path 63 and the groove 64 of the exhaust flow path are connected to each other on the upper surface 53-1, forming a transmission path 66 that transmits the negative pressure from the negative pressure transmission path 65 to the lower surface of the porous member 51. The negative pressure transmitted to the lower surface of the porous member 51 by the transmission path 66 is transmitted to the holding surface 56 via the plurality of pores in the porous member 51 .

[0078] In this way, the chuck worktable 50 utilizes the negative pressure transmitted to the holding surface 56 through the negative pressure transmission path 65 and the transmission path 66 via the multiple holes in the porous component 51, and utilizes the holding surface 56 to attract and hold the front side 101 of the chip 100 from the bottom, so that the back side 104 of the chip 100 is exposed to the upper side.

[0079] The reflector 54 is disposed at a position lower than the support member 53. Specifically, the reflector 54 is disposed in a space formed at a lower side of a position for holding the support member 53 in the circular recess 52-1 of the base member 52. The reflector 54 is disposed at the lower side of the porous member 51 and the support member 53, and is disposed at a position higher than the concavoconvex (the suction path 61 and the groove 62 of the exhaust flow path) of the bottom surface of the circular recess 52-1.

[0080] The reflector 54 is made of a conductive material that reflects microwaves and has a flat surface 57. Here, reflecting microwaves means that the reflectivity of microwaves is 80% or more. That is, the reflectivity of microwaves of the reflector 54 is 80% or more. Preferably, the reflectivity of microwaves of the reflector 54 is 90% or more, and more preferably 95% or more. In addition, the conductive material refers to a material having electrical conductivity, and as mentioned above, it refers to a material having electrical conductivity of 1×10 -6 S / m or higher. Since the reflector 54 has such high conductivity, it appropriately has the property of reflecting microwaves as described above.

[0081] The reflector 54 includes any material selected from stainless steel, iron, an alloy containing iron, aluminum, an alloy containing aluminum, copper, an alloy containing copper, titanium, and CFRP (Carbon Fiber Reinforced Plastic). The reflector 54 may be made of any material selected from stainless steel, iron, an alloy containing iron, aluminum, an alloy containing aluminum, copper, an alloy containing copper, titanium, and CFRP, or may be made of a composite material of two or more thereof. The reflector 54 may also include the same conductive material that reflects microwaves as stainless steel, iron, an alloy containing iron, aluminum, an alloy containing aluminum, copper, an alloy containing copper, titanium, and CFRP. In addition, the reflector 54 may also include an appropriate amount of additives.

[0082] The reflector 54 made of stainless steel, iron, an alloy containing iron, aluminum, an alloy containing aluminum, copper, an alloy containing copper, titanium, or CFRP has high conductivity and a thickness of 3 mm. The reflectivity of the reflector 54 to microwaves with a frequency of 25 GHz is about 100%, the absorptivity to microwaves with a frequency of 25 GHz is almost 0%, and the transmittance to microwaves with a frequency of 25 GHz is almost 0%. In addition, the thickness of the reflector 54 made of stainless steel, iron, an alloy containing iron, aluminum, an alloy containing aluminum, copper, an alloy containing copper, titanium, or CFRP is not limited to 3 mm, and the reflectivity, absorptivity, and transmittance to microwaves vary depending on the thickness and temperature.

[0083] In the gettering performance evaluation device 1-3 of the second embodiment having the above-described structure, the chuck table 50 includes a reflector 54, which is disposed at a lower side than the porous member 51 and the support member 53 having microwave transparency, and has a flat surface 57 made of a conductive material that reflects microwaves. Therefore, in the gettering performance evaluation device 1-3 of the second embodiment, more than 80% of the light beam of the microwave 17 irradiated by the transmitting and receiving unit 12 is transmitted through the unevenness of the support member 53, reflected by the flat surface 57 of the reflector 54, and becomes a part of the reflected wave 18 of the microwave and is received by the transmitting and receiving unit 12, and therefore does not reach the unevenness of the base member 52. Furthermore, in the gettering performance evaluation device 1-3 of the second embodiment, the component that is reflected by the flat surface 57 of the reflector 54 and becomes a part of the reflected wave 18 of the microwave becomes a DC component in the measurement signal processed by the transmitting and receiving unit 12 and the determination unit 13, so the determination unit 13 can easily remove the component from the measurement signal. Therefore, in the defect removal performance evaluation device 1-3 of the second embodiment, when the specified position 120 is moved, the possibility that the intensity of the reflected wave 18 of the microwave will change due to the unevenness of the base component 52 and the unevenness of the support component 53 can be reduced, thereby achieving the following effect: the influence of the chuck worktable 50 that attracts and holds the chip 100 on the defect removal performance evaluation can be reduced.

[0084] In the gettering performance evaluation device 1-3 of the second embodiment, the reflector 54 includes any material selected from stainless steel, iron, an alloy containing iron, aluminum, an alloy containing aluminum, copper, an alloy containing copper, titanium, and CFRP. Therefore, the gettering performance evaluation device 1-3 of the second embodiment can reflect a higher proportion of the light beam of the microwave 17 by the flat surface 57 of the reflector 54, so that when the predetermined position 120 is moved, the following effect is achieved: the possibility that the intensity of the reflected wave 18 of the microwave changes due to the unevenness of the base member 52 and the unevenness of the support member 53 can be reliably reduced, and the influence of the chuck table 50 that attracts and holds the wafer 100 on the evaluation of the gettering performance can be reliably reduced.

[0085] [Second variant]

[0086] A gettering property evaluation device 1 - 4 according to a modification (second modification) of the second embodiment of the present invention will be described with reference to the drawings. Fig. 9 FIG. 1 is a cross-sectional view of a gettering performance evaluation device 1-4 according to a second variant. Fig. 9 In the present invention, the same parts as those in the second embodiment are denoted by the same reference numerals and description thereof is omitted.

[0087] like Fig. 9As shown, the defect removal performance evaluation device 1-4 of the second modified example is obtained by replacing the chuck table 50 with a chuck table 50-2 in the defect removal performance evaluation device 1-3 of the second embodiment. The chuck table 50-2 is a component obtained by replacing the base member 52 with a base member 52-2 and replacing the support member 53 with a support member 53-2 in the chuck table 50.

[0088] The base member 52-2 is a member having a plurality of suction paths 67 formed inside the base member 52 instead of the groove 62 of the exhaust flow path. The suction path 61 is formed with projections and depressions on the bottom surface of the circular depression of the base member 52-2. The suction path 61 formed in the base member 52-2 and the plurality of suction paths 67 are interconnected to form a negative pressure transmission path 65-2 for transmitting the negative pressure from the suction source 59 to the inside of the support member 53-2.

[0089] The support member 53-2 is a member in which a plurality of holes 68 and a suction path 69 are formed in place of the grooves 64 of the suction path 63 and the exhaust flow path in the support member 53. The plurality of holes 68 are formed from the upper surface of the support member 53-2 to a depth of the upper half, and are connected to the suction path 69 on the lower side. The suction path 69 connects the plurality of holes 68 in the radial direction, and is connected to the plurality of suction paths 67 of the negative pressure transmission path 65-2 on the outer periphery. The plurality of holes 68 form a concave-convex shape on the upper surface of the support member 53-2. The plurality of holes 68 and the suction path 69 formed in the support member 53-2 are connected to each other, forming a transmission path 66-2 that transmits the negative pressure from the negative pressure transmission path 65-2 to the lower surface of the porous member 51.

[0090] The gettering performance evaluation device 1-4 of the second modified example is a device in which the structures of the negative pressure transmission path 65 and the transmission path 66 are changed in the gettering performance evaluation device 1-3 of the second embodiment to form a negative pressure transmission path 65-2 and a transmission path 66-2. Therefore, the gettering performance evaluation device 1-4 of the second modified example has the same effects as the gettering performance evaluation device 1-3 of the second embodiment.

[0091] [Third embodiment]

[0092] A gettering property evaluation device 1 - 5 according to a third embodiment of the present invention will be described with reference to the drawings. Fig.10 2 is a cross-sectional view of a configuration example of a gettering performance evaluation device 1-5 according to a third embodiment. Fig.10 In the present invention, the same parts as those in the second embodiment are denoted by the same reference numerals and description thereof is omitted.

[0093] like Fig.10As shown, the gettering performance evaluation device 1-5 of the third embodiment is obtained by replacing the chuck table 50 with a chuck table 50-3 in the gettering performance evaluation device 1-3 of the second embodiment. The chuck table 50-3 is obtained by replacing the reflector 54 with a radio wave absorber 74 in the chuck table 50.

[0094] Similar to the reflector 54 of the second embodiment, the radio wave absorber 74 is disposed at a position lower than the support member 53. Specifically, similar to the reflector 54 of the second embodiment, the radio wave absorber 74 is disposed in the circular recess 52-1 of the base member 52 in a space formed at the lower side of the position for holding the support member 53. The radio wave absorber 74 is disposed at the lower side of the porous member 51 and the support member 53, and is disposed at a position higher than the concavoconvex (the suction path 61 and the groove 62 of the exhaust flow path) of the bottom surface of the circular recess 52-1.

[0095] The radio wave absorber 74 is made of a material that absorbs microwaves. Here, absorbing microwaves means that the absorption rate of microwaves is 80% or more. That is, the absorption rate of microwaves by the radio wave absorber 74 is 80% or more. Preferably, the absorption rate of microwaves by the radio wave absorber 74 is 90% or more, and more preferably 95% or more.

[0096] The radio wave absorber 74 is made of any material including a magnetic radio wave absorber, a dielectric radio wave absorber, a conductive radio wave absorber, and a λ / 4 type radio wave absorber. The magnetic radio wave absorber, the dielectric radio wave absorber, the conductive radio wave absorber, and the λ / 4 type radio wave absorber all have a microwave absorption rate of about 100% when the thickness is 3 mm.

[0097] In the gettering performance evaluation apparatus 1-5 of the third embodiment having the above-described structure, the chuck table 50-3 has a radio wave absorber 74, which is disposed at a lower side than the porous member 51 and the support member 53 having microwave permeability, and is made of a material that absorbs microwaves. Therefore, in the gettering performance evaluation apparatus 1-5 of the third embodiment, more than 80% of the beam of the microwave 17 irradiated by the transmitting and receiving unit 12 is absorbed by the radio wave absorber 74 through the unevenness of the support member 53, and thus does not reach the unevenness of the base member 52. Therefore, similarly to the gettering performance evaluation apparatus 1-3 of the second embodiment, the gettering performance evaluation apparatus 1-5 of the third embodiment can reduce the possibility that the intensity of the reflected wave 18 of the microwave will change due to the unevenness of the base member 52 and the unevenness of the support member 53 when the predetermined position 120 is moved, thereby achieving the following effect: the influence of the chuck table 50-3 that attracts and holds the wafer 100 on the evaluation of the gettering performance can be reduced.

[0098] In the gettering performance evaluation device 1-5 of the third embodiment, the radio wave absorber 74 includes any radio wave absorber selected from the group consisting of a magnetic radio wave absorber, a dielectric radio wave absorber, a conductive radio wave absorber, and a λ / 4 type radio wave absorber. Therefore, the gettering performance evaluation device 1-5 of the third embodiment can absorb a higher proportion of the microwave 17 beam by the radio wave absorber 74, and thus, when the predetermined position 120 is moved, the following effects are achieved: the possibility that the intensity of the reflected wave 18 of the microwave changes due to the unevenness of the base member 52 and the unevenness of the support member 53 can be reliably reduced, thereby reliably reducing the influence of the chuck table 50 that attracts and holds the wafer 100 on the evaluation of the gettering performance.

[0099] In addition, in the case where the defect removal evaluation device 1-5 of the third embodiment uses a foam such as polyurethane as the radio wave absorber 74, if the foam is a continuous bubble, the continuous bubble plays the same role as the negative pressure transmission path 65, and therefore the negative pressure transmission path 65 (the groove 62 of the suction path 61 and the exhaust flow path) may not be provided on the base component 52.

[0100] [Fourth embodiment]

[0101] A grinding and polishing device 200 according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig.11 2 is a perspective view of a configuration example of a grinding and polishing device 200 according to a fourth embodiment. Fig.11 In the present invention, the same parts as those in the above-mentioned embodiment are denoted by the same reference numerals and description thereof is omitted.

[0102] In the grinding and polishing device 200 of the fourth embodiment, Fig.11 As shown, the chuck table 20 of the first embodiment is arranged on a turntable 210, and the gettering determination unit 10 of the first embodiment is provided toward the loading and unloading position of the wafer 100 on the turntable 210. Thus, the grinding and polishing apparatus 200 of the fourth embodiment incorporates the gettering performance evaluation apparatus 1 of the first embodiment.

[0103] In the grinding and polishing device 200 of the fourth embodiment, after the wafer 100 held by suction on the chuck table 20 is rough ground, fine ground and polished at the rough grinding position, fine grinding position and polishing position on the turntable 210 using the rough grinding unit 220, the fine grinding unit 230 and the polishing unit 240 respectively, the defect removal property of the defect removal layer 110 formed in the wafer 100 by the rough grinding, fine grinding and polishing is evaluated at the loading and unloading position using the defect removal judgment unit 10.

[0104] The grinding and polishing apparatus 200 of the fourth embodiment includes the gettering property evaluation apparatus 1 of the first embodiment, and the gettering property is evaluated by using the gettering property evaluation apparatus 1 of the first embodiment, so that the same effects as those of the gettering property evaluation apparatus 1 of the first embodiment are achieved. In addition, the grinding and polishing apparatus 200 of the fourth embodiment achieves the following effects: the gettering property of the gettering layer 110 formed on the back surface 104 side of the wafer 100 by rough grinding by the rough grinding unit 220, fine grinding by the fine grinding unit 230, and polishing by the polishing unit 240 can be easily evaluated by using the gettering property evaluation apparatus 1 of the first embodiment located in the same apparatus directly after grinding and polishing.

[0105] In addition, in the present invention, in addition to the chuck table 20 of the first embodiment, the chuck tables 20 - 2 , 50 , 50 - 2 , and 50 - 3 of other embodiments and modifications may be arranged on the turntable 210 .

[0106] [Example]

[0107] Next, the inventors of the present invention confirmed the effect of the gettering performance evaluation device 1 of the first embodiment. In the confirmation, in an embodiment using a chuck table 20 having a metal porous member 21 containing porous SiC and a comparative example using an existing chuck table, when a predetermined position 120 is moved along a predetermined path on a wafer 100, a change in the intensity of the reflected wave 18 of the microwave received by the transmitting and receiving unit 12 is detected, wherein the existing chuck table has an existing porous member containing alumina ceramics instead of the non-metallic porous member 21, and the other structures are the same as those of the gettering performance evaluation device 1 of the first embodiment. Fig.12 It is a graph showing the intensity distribution of reflected waves of microwaves received by the gettering property evaluation apparatuses of the example and the comparative example.

[0108] In the embodiment using the chuck table 20 having the non-metallic porous member 21 comprising porous SiC, Fig.12 As shown by the solid line in the middle, a curve 301 is obtained in which the intensity of the reflected wave 18 of the microwave is substantially constant. On the other hand, in the comparative example using the existing chuck table, as shown in FIG. Fig.12 As shown by the middle dotted line, a curve 302 is obtained in which the intensity of the reflected wave of the microwave changes greatly.

[0109] according to Fig.12In the comparative example, the intensity of the reflected wave of the microwave varies greatly depending on the evaluation area, whereas in the embodiment, the intensity of the reflected wave 18 of the microwave is substantially constant regardless of the predetermined position 120. In the comparative example, the irradiated microwave passes through the existing porous member made of alumina ceramics and is reflected by the bottom surface of the concave-convex recess 22-1 of the base member 22 constituting the lower side of the porous member and the bottom surface of the groove 27 of the exhaust flow path. At this time, in the comparative example, when the distance between the transmitting and receiving unit 12 and the bottom surface of the recess 22-1 is 16 mm and the depth of the groove 27 of the exhaust flow path is 1 mm, the propagation distance of the microwave reflected by the bottom surface of the groove 27 of the exhaust flow path is increased by 2 mm compared to the propagation distance of the microwave reflected by the bottom surface of the recess 22-1. In the comparative example, regarding the reflected wave of the microwave, according to the Friis transmission equation, the received intensity (received power) of the microwave reflected by the bottom surface of the groove 27 of the exhaust flow path is 21% less than the received intensity (received power) of the microwave reflected by the bottom surface of the recess 22-1. In contrast, in the embodiment, the irradiated microwave 17 is reflected by the flat holding surface 24 of the non-metallic porous member 21.

[0110] Therefore, according to Fig.12 It can be seen that in the present invention, the chuck worktable 20 has a conductive non-metallic porous component 21, which constitutes a holding surface 24 and has the property of reflecting or absorbing microwaves, so that more than 80% of the light beam of the microwave 17 irradiated by the sending and receiving unit 12 will not reach the unevenness of the base component 22. Therefore, when the specified position 120 is moved, the possibility of the intensity of the reflected wave 18 of the microwave changing due to the unevenness of the base component 22 can be reduced.

[0111] In addition, the present invention is not limited to the above-mentioned embodiments and modified examples. That is, it can be implemented by various modifications within the scope of the main purpose of the present invention. For example, in the gettering performance evaluation devices 1, 1-2, 1-3, 1-4, and 1-5 of the above-mentioned embodiments and modified examples, the gettering performance of the gettering layer 110 can also be evaluated by the gettering judgment unit 10 based on the differential signal, which is the difference between the reflected waves 18 of the microwave measured in the area irradiated with the laser beam 15 and the area not irradiated with the laser beam 15. In addition, the gettering performance evaluation devices 1, 1-2, 1-3, 1-4, and 1-5 of the above-mentioned embodiments and modified examples evaluate the gettering performance of the gettering layer 110 of the wafer 100, but the gettering performance evaluation device of the present invention is not limited to a device that only evaluates the gettering performance, and can also be a device that can measure material properties other than the gettering performance of the wafer 100 and the gettering layer 110 by the μ-PCD method.

Claims

1. A defect-removal evaluation device, wherein: The defect-removal evaluation device comprises: a gettering determination unit including a laser beam irradiation unit for irradiating a laser beam to the wafer and a transmitting and receiving unit for irradiating microwaves to the wafer and receiving microwaves reflected by the wafer, the gettering determination unit determining whether a gettering layer including grinding strain generated by grinding the wafer has gettering properties; as well as a chuck table that holds the wafer with a holding surface, The chuck table has: A conductive non-metallic porous component constituting the holding surface and having a property of reflecting or absorbing the microwave; as well as The base member exposes the holding surface and surrounds the non-metal porous member, and has a negative pressure transmission path for transmitting negative pressure to the non-metal porous member.

2. The gettering performance evaluation device according to claim 1, wherein: The non-metallic porous component is made of a material whose sum of microwave reflectivity and microwave absorptivity is greater than 80%.

3. The gettering performance evaluation device according to claim 1 or 2, wherein: The non-metallic porous component comprises porous SiC or porous carbon.

4. A defect-removal evaluation device, wherein: The defect-removal evaluation device comprises: a gettering determination unit including a laser beam irradiation unit for irradiating a laser beam to the wafer and a transmitting and receiving unit for irradiating microwaves to the wafer and receiving microwaves reflected by the wafer, the gettering determination unit determining whether a gettering layer including grinding strain generated by grinding the wafer has gettering properties; as well as a chuck table that holds the wafer with a holding surface, The chuck table has: A porous member constituting the holding surface and having permeability to the microwaves; a base member having a negative pressure transmission path for transmitting negative pressure to the porous member; a supporting member, which is made of a material that is transparent to the microwaves, is disposed below the porous member, supports the porous member, and has a transmission path for transmitting the negative pressure from the negative pressure transmission path to the porous member; as well as The reflecting plate is disposed below the supporting member, is made of a conductive material that reflects the microwaves, and has a flat surface.

5. The gettering performance evaluation device according to claim 4, wherein: The reflective plate includes any material selected from the group consisting of stainless steel, iron, an alloy containing iron, aluminum, an alloy containing aluminum, copper, an alloy containing copper, titanium, and carbon fiber reinforced plastic.

6. A defect-removal evaluation device, wherein: The defect-removal evaluation device comprises: a gettering determination unit including a laser beam irradiation unit for irradiating a laser beam to the wafer and a transmitting and receiving unit for irradiating microwaves to the wafer and receiving microwaves reflected by the wafer, the gettering determination unit determining whether a gettering layer including grinding strain generated by grinding the wafer has gettering properties; as well as a chuck table that holds the wafer with a holding surface, The chuck table has: A porous member constituting the holding surface and having permeability to the microwaves; a base member having a negative pressure transmission path for transmitting negative pressure to the porous member; a supporting member, which is made of a material that is transparent to the microwaves, is disposed below the porous member, supports the porous member, and has a transmission path for transmitting the negative pressure from the negative pressure transmission path to the porous member; as well as The radio wave absorber is disposed below the support member and is made of a material that absorbs the microwave.

7. The getterability evaluation device according to claim 6, wherein: The radio wave absorber includes any of a magnetic radio wave absorber, a dielectric radio wave absorber, a conductive radio wave absorber, and a λ / 4 type radio wave absorber.

Images