Detector and wafer cooling method

Abstract

Excess heat of a wafer is efficiently removed. A probe (1) is provided with: a wafer chuck (34) which is a support member for supporting a wafer (W); an inspection unit that inspects the electrical characteristics of a semiconductor device formed on the wafer (W) when the wafer (W) is placed on the wafer chuck (34); an injection unit that sends air (A2) to an air purge passage (112) connected to a chuck space (CS) formed on the wafer chuck (34); and a cooling control unit that determines whether or not the air (A2) can be injected.

Description

Technical Field

[0001] The invention relates to a wafer heat removal technology. Background Art

[0002] In the early stages of semiconductor manufacturing, wafers with multiple devices formed on them are separated into individual chips during the dicing process. Before this dicing process, defective devices on the wafer must be removed. A prober is a device used to inspect the electrical characteristics of devices formed on the wafer.

[0003] The prober includes a probe card with multiple probes. The probes are electrically connected to a test head. By placing the wafer against the probe card, each probe contacts the electrode pads of each device. Electricity flows from the test head through the probes to each device, and the electrical characteristics are inspected to determine if the device is defective.

[0004] However, with the recent increase in wafer size and integration, the number of devices formed on each wafer has also increased. Consequently, in order to increase throughput and reduce costs in semiconductor manufacturing, there is a demand for improved inspection efficiency. Consequently, a so-called multi-stage, multi-bench probe has been proposed, in which multiple test heads are arranged horizontally on multiple levels. This probe allows multiple test stages to be inspected simultaneously and continuously, thereby improving inspection efficiency.

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2-65253 Summary of the Invention

[0008] Technical problem to be solved by the invention

[0009] The above-mentioned wafer electrical characteristic inspection (hereinafter referred to as "wafer inspection") is obtained by considering the actual use environment in order to ensure the functionality of the device. According to the specifications of the device, it is performed at a high temperature set at around 85 degrees.

[0010] During wafer inspection, the flow of electricity causes the devices themselves to heat up. In recent years, device heat generation has been increasing. Consequently, there's a risk that device temperatures may exceed the set temperature during wafer inspection. Therefore, in order to maintain the set temperature during wafer inspection in high-temperature environments, it's necessary to remove excess heat from the devices.

[0011] Heat removal using fans or coolant is also an option, but adding new, large-scale heat removal equipment is not preferred in terms of cost and space savings. In particular, the possibility of boiling the coolant in a high-temperature environment must be considered. Furthermore, the inventors of the present invention have verified that while the temperature of the outer edge of the wafer drops relatively quickly, heat tends to accumulate in the center of the wafer due to "localized heat distribution." Therefore, the inventors believe that localized heat removal is necessary, targeting not only the entire wafer but also the localized high-heat areas of the wafer.

[0012] The present invention was completed based on the understanding of the above-mentioned technical problems by the inventors of the present invention, and a main object of the present invention is to provide a technology for efficiently removing heat from a wafer.

[0013] Methods used to solve technical problems

[0014] A detector according to one embodiment of the present invention includes: a supporting component that supports a wafer and includes a first passage through which a first gas can pass and a second passage that merges with the first passage; an inspection unit that inspects the electrical characteristics of a semiconductor device formed on the wafer when the wafer is placed on the supporting component; an injection unit that injects a second gas into the second passage; and a cooling control unit that instructs the injection unit whether the second gas can be injected.

[0015] A detector according to another embodiment of the present invention includes: a supporting component that supports a wafer and includes a first passage through which a first gas can pass and a second passage that merges with the first passage; an inspection component that inspects the electrical characteristics of a semiconductor device formed on a wafer when the wafer is placed on the supporting component; a suction component that draws the first gas from the second passage; and a cooling control component that instructs the suction component whether the first gas can be drawn.

[0016] A wafer cooling method according to one aspect of the present invention is performed in a prober that supports a wafer by a support member and inspects electrical characteristics of a semiconductor device formed on the wafer.

[0017] The support member includes a first passage through which the first gas can pass and a second passage that merges with the first passage.

[0018] The cooling method includes: determining whether the second gas can be sprayed into the second passage based on the temperature of the wafer; and spraying the second gas into the second passage when the spraying of the second gas is permitted.

[0019] Effects of the Invention

[0020] According to the present invention, heat from a wafer can be removed easily and efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram showing a schematic configuration of a detector according to an embodiment.

[0022] Figure 2 It is a horizontal cross-sectional view schematically showing the internal structure of the detector.

[0023] Figure 3 yes Figure 2 A-A arrow cross-section diagram.

[0024] Figure 4 yes Figure 3 Enlarged view of part B.

[0025] Figure 5 It is a diagram showing the configuration of a measuring unit.

[0026] Figure 6 It is a side view of the wafer chuck according to this embodiment.

[0027] Figure 7 This is a conceptual diagram of the heat distribution of wafer W.

[0028] Figure 8 This is a conceptual diagram for explaining the heat removal method of this embodiment.

[0029] Figure 9 It is a cross-sectional view of the wafer chuck according to this embodiment.

[0030] Figure 10 yes Figure 9 An enlarged view of the area near the discharge hole.

[0031] Figure 11 is a schematic diagram showing the set points of the temperature sensor.

[0032] Figure 12 This is a diagram of the system configuration related to wafer chuck temperature control.

[0033] Figure 13 This is a flowchart showing the processing procedure of air delivery control.

[0034] Figure 14 This is a cross-sectional view of a wafer chuck according to Modification 1.

[0035] Figure 15 This is a cross-sectional view of a wafer chuck according to Modification 2.

[0036] Figure 16 This is a cross-sectional view of a wafer chuck according to Modification 3.

[0037] Figure 17 This is an external view of the back side of the top plate of Modification 3.

[0038] Figure 18 yes Figure 17 Enlarged view of the central part.

[0039] Figure 19This is an external view of the surface of the back plate of Modification 4.

[0040] Figure 20 This is a cross-sectional view of a wafer chuck according to Modification 4.

[0041] Figure 21 This is a cross-sectional view of a wafer chuck according to Modification 5. DETAILED DESCRIPTION

[0042] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the following embodiments and their modifications, substantially the same components are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0043] The prober of this embodiment inspects the electrical characteristics of semiconductor devices (also simply referred to as "devices") formed on a wafer. The prober is provided with a plurality of regions including an inspection region and a transfer region.

[0044] Figure 1 It is a diagram showing a schematic configuration of a detector according to an embodiment.

[0045] It should be noted that, for convenience of description, the left-right direction, the front-back direction, and the up-down direction viewed from the front of the device will be described as the X direction, the Y direction, and the Z direction, respectively.

[0046] The prober 1 has a housing 2 that is rectangular in both front and top views. Inside the housing 2 are a measurement area 10 for wafer inspection and a loading area 12 for transporting wafers to and from the measurement area 10. The loading area 12 includes a storage area 14 for accommodating wafers or probe cards.

[0047] The storage area 14 is equipped with a wafer storage unit 16 for wafers and a card storage unit 18 for probe cards. The wafer storage unit 16 receives a FOUP (form-based unpacking unit) that holds multiple wafers. Operators or robots can access each storage unit from the front to retrieve wafers or probe cards. A loading door 4 is located on the side of the housing 2, allowing operators to enter and exit the loading area.

[0048] The detector 1 is also equipped with a control unit 20 and an operation panel 22. The control unit 20 is composed of a general-purpose computer and includes a CPU that performs various calculations, a memory or storage device that stores control programs, a memory used as a work area for data storage or program execution, an input / output interface, and a user interface. The user interface receives operator input via the operation panel 22. The control unit 20 controls the various functional units (mechanisms and devices) of the detector 1 according to the control program.

[0049] Figure 2 It is a horizontal cross-sectional view schematically showing the internal structure of the probe 1 .

[0050] The probe 1 includes a measurement area 10 and a loading area 12. The measurement area 10 includes an inspection area (described later). The measurement area 10 and the loading area 12 are separated by a partition wall provided in the housing 2. The loading area 12 includes a storage area 14 and a transfer area 15. A transfer unit 24 for transferring wafers W or probe cards (described later) is movably arranged in the transfer area 15.

[0051] Multiple measurement units 30 for wafer inspection are provided in the measurement area 10. In this embodiment, a multi-stage, multi-stage prober is employed, with three stages arranged vertically. Each stage has four measurement units 30 arranged horizontally. However, the number of stages and arrangements can be set as desired.

[0052] The measurement area 10 is equipped with an alignment device 32, which is common to all measurement units 30. The alignment device 32 removably supports a wafer chuck 34. The wafer chuck 34 holds the wafer W by vacuum suction and secures it. During the probing process, it is loaded and unloaded from the test head of the measurement unit 30 (details will be described later). The alignment device 32 can move between the multiple measurement units 30 arranged in a horizontal direction. The operation of the alignment device 32 allows the wafer chuck 34 to move in the X, Y, and Z directions within the measurement area 10 and can also rotate about the Z axis (θ direction).

[0053] The transport unit 24 transports wafers W between the wafer storage unit 16 and each measurement unit 30, and transports probe cards between the card storage unit 18 and each measurement unit 30. The transport unit 24 includes an arm 26 for transferring wafers W. The transport unit 24 is a transport device shared by all the measurement units 30. By omitting the operation of a drive mechanism (not shown), the transport unit 24 is movable in the X and Z directions and rotatable about the Z axis (θ direction).

[0054] The transport unit 24 operates an arm drive mechanism (not shown) to move the arm 26 forward and backward (extend and retract). Wafers W in the wafer storage unit 16 are removed by the arm 26 and transported to each measurement unit 30 via the transport unit 24. After inspection, wafers W are returned from each measurement unit 30 to the wafer storage unit 16 via the reverse path.

[0055] Figure 3 yes Figure 2 A-A arrow cross-section diagram. Figure 4 yes Figure 3 Enlarged view of part B.

[0056] like Figure 3As shown, the measurement area 10 is provided with three levels of measurement units 30, one above the other. Each measurement unit 30 is divided into an inspection area 40 and a machine storage area 42 by partition walls 36. The inspection area 40 is an area where wafers W to be inspected are arranged and is located relatively below. The machine storage area 42 is an area where other electrical equipment such as a test head 44 is accommodated and is located relatively above. The inspection area 40 is separated from the transfer area 15 by a partition wall 38, and the machine storage area 42 is separated from the transfer area 15 by a partition wall 39. The machine storage area 42 and the transfer area 15 correspond to "outer areas" that are separately divided from the inspection area 40.

[0057] In more detail, Figure 4 As shown, the alignment device 32 is disposed in the inspection area 40. The partition wall 38 is provided with an opening 46 that connects the inspection area 40 and the transfer area 15, and a shutter 48 that opens and closes the opening 46. By opening the shutter 48, the arm 26 of the transfer unit 24 can enter and exit the inspection area 40. In other words, wafers W can be transferred between the transfer unit 24 and the alignment device 32.

[0058] Meanwhile, a test head 44 and electrical equipment (not shown) are located in the equipment storage area 42. An elastic frame 54 is provided at the boundary between the inspection area 40 and the equipment storage area 42. The elastic frame 54 functions as an interface connecting the test head 44 and a probe card (described later).

[0059] Each area is provided with a discharge unit for discharging dry air to prevent condensation. A discharge unit 56 is provided in the inspection area 40 , a discharge unit 58 is provided in the equipment storage area 42 , and a discharge unit 60 is also provided in the transfer area 15 .

[0060] Figure 5 is a diagram showing the structure of the measuring unit 30, corresponding to Figure 4 C-C arrow section.

[0061] like Figure 5 As shown, the measurement unit 30 includes a wafer chuck 34, a test head 44, an elastic frame 54, a head stage 62, and a probe card 64. The probe card 64 has a plurality of probes 65 for supplying power to the wafer W.

[0062] The elastic frame 54 and the header platform 62 constitute a part of the partition wall 36. In the central part of the header platform 62, a mounting hole 66 of a complementary shape (circular) is provided for mounting the elastic frame 54. The elastic frame 54 is mounted in a manner that fits into the mounting hole 66, so that the mounting hole 66 is closed. The header platform 62 has an adsorption surface that can adsorb the elastic frame 54, and the elastic frame 54 is adsorbed and fixed by operating an aspiration device (such as a vacuum pump) not shown in the figure. The airtightness of the boundary between the header platform 62 and the elastic frame 54 is maintained. In addition, in a modified example, the header platform 62 and the elastic frame 54 can also be fixed by a fixing structure such as screws.

[0063] The test head 44 is supported above the head stage 62. The test head 44 is electrically connected to the probes 65 of the probe card 64. During inspection, the test head 44 supplies test signals (electrical signals) to each device on the wafer W, detects the output signals from each device, and obtains electrical characteristics. This allows the device to be checked for proper operation.

[0064] The elastic frame 54 includes a plurality of spring pins 68 that electrically connect the terminals formed on the lower surface of the test head 44 (the surface facing the elastic frame 54) to the terminals formed on the upper surface of the probe card 64 (the surface facing the elastic frame 54). Furthermore, sealing rings 70 and 72 are provided on the periphery of the upper surface (the surface facing the test head 44) ​​and the lower surface (the surface facing the probe card 64) of the elastic frame 54, respectively.

[0065] By operating suction device 74 (e.g., a vacuum pump), the pressure in the space surrounded by test head 44, elastic frame 54, and seal ring 70 and the space surrounded by probe card 64, elastic frame 54, and seal ring 72 is reduced. Thus, test head 44, elastic frame 54, and probe card 64 are integrated.

[0066] This structure separates the inner space (i.e., the inspection area 40) from the outer space (i.e., the equipment storage area 42) separated by the partition wall 36 including the head stage 62 and the elastic frame 54. Furthermore, in this embodiment, when the probe card 64 is replaced, it may be removed from the elastic frame 54. However, the sealing ring 70 also functions during this time, thereby ensuring airtightness between the inspection area 40 and the equipment storage area 42.

[0067] The probe card 64 includes a plurality of probes 65 corresponding to the electrodes of each device on the inspection target wafer W. As described above, when the test head 44, the elastic frame 54, and the probe card 64 are integrated, each probe 65 is electrically connected to each terminal of the test head 44 via the elastic frame 54. The probe card 64 includes a plurality of probes 65 corresponding to the electrodes of all devices on the inspection target wafer W, allowing the measurement unit 30 to simultaneously inspect all devices on the wafer W.

[0068] The wafer chuck 34 suction-holds and fixes the wafer W. The wafer chuck 34 is detachably supported by the alignment device 32 . The alignment device 32 includes an X stage 76 , a Y stage 78 , and a Z stage 80 .

[0069] A guide rail extending in the X direction is provided in the housing 2, and an X-platform 76 is horizontally mounted so as to be movable along the guide rail in the X direction. The X-platform 76 is driven by a movable mechanism (not shown). A guide rail extending in the Y direction is provided on the upper surface of the X-platform 76. A Y-platform 78 is horizontally mounted so as to be movable along the guide rail in the Y direction. The Y-platform 78 is driven by a movable mechanism (not shown). Each movable mechanism is implemented by a screw feed mechanism and a stepping motor driving it, or alternatively, a linear motor.

[0070] The Z platform 80 is supported by the Y platform 78 so as to be able to be raised and lowered in the Z direction and to be rotated in the θ direction. A lifting mechanism for raising and lowering the Z platform 80 and a rotating mechanism (not shown) for rotating the Z platform 80 are provided on the Y platform 78. The rotating mechanism is implemented, for example, by a spindle motor. The wafer chuck 34 is detachably supported on the upper surface of the Z platform 80. According to such a structure, the wafer chuck 34 can move in the X direction, the Y direction, the Z direction and the θ direction respectively. By moving the wafer chuck 34, the relative positioning of the wafer W and the probe card 64 can be performed.

[0071] A snap-on seal rubber 82 (seal ring) is provided on the upper surface of the wafer chuck 34 so as to surround the wafer W. During the probing process, the Z stage 80 is moved, causing the wafer chuck 34 to move (or rise and fall) toward the probe card 64. At this time, the snap-on seal rubber 82 abuts against the lower surface of the probe card 64, thereby forming a space surrounded by the wafer chuck 34, the probe card 64, and the snap-on seal rubber 82. By operating a suction device (not shown) (e.g., a vacuum pump), the pressure in this space is reduced, and the wafer chuck 34 is attracted to the probe card 64. As a result, the probes 65 of the probe card 64 abut against the components on the wafer W, enabling wafer inspection.

[0072] At this time, by detaching the Z stage 80 from the wafer chuck 34, the alignment device 32 can be used for another measuring unit 30. As described above, the alignment device 32 is common to the measuring units 30 of each stage. Therefore, while one measuring unit 30 is performing inspection, the wafer W can be transferred to another measuring unit 30.

[0073] Figure 6 It is a side view of the wafer chuck 34 of this embodiment.

[0074] The wafer chuck 34 is a disc-shaped "support member" on which the wafer W is placed. The wafer chuck 34 includes a top plate 100 and a backing plate 102. The top plate 100 (chuck top) is formed of a conductive material such as metal because it functions as a measurement electrode during wafer inspection. The top plate 100 also incorporates a heater (described later) for heating the wafer W.

[0075] The back plate 102 is formed of a high insulating material such as ceramic to prevent leakage current during wafer inspection. The top plate 100 and the back plate 102 are connected by screws via a plurality of spacers 104. Through the spacers 104, a gap (hereinafter referred to as "chuck space CS") can be formed between the top plate 100 and the back plate 102. The top plate 100 is heated by the heat of the wafer W and the heater, so the air in the chuck space CS also becomes high temperature (hereinafter, the air after the heating is referred to as "high temperature air"). The high temperature air is removed by flowing dry room temperature or low temperature air (hereinafter, simply referred to as "air") in the chuck space CS.

[0076] Figure 7 This is a conceptual diagram of the heat distribution of wafer W.

[0077] During wafer inspection, the entire wafer W is heated by a heater. Furthermore, each device formed on the wafer W generates heat as current flows through it during wafer inspection. During wafer inspection in a high-temperature environment (hereinafter referred to as "high-temperature inspection"), the devices also generate heat. During high-temperature inspection, it is necessary to maintain a set temperature while taking into account the heat generated by the devices.

[0078] During high-temperature inspection, the heat generated from the wafer W and the wafer chuck 34 escapes from the outer edge to the outside air little by little. Therefore, it is relatively easy to reduce the temperature of the outer edge 108 of the wafer W. On the other hand, the heat of the center 106 of the wafer W is conducted to the outer edge 108 and then escapes to the outside air. Therefore, compared with the outer edge 108, the temperature of the center 106 is difficult to reduce. Therefore, during high-temperature inspection, when the heat generated by the wafer W is large, the center 106 sometimes becomes above the set temperature. In order to keep the entire wafer W near the set temperature (measurement temperature), it is particularly necessary to promote the removal of heat from the center 106.

[0079] Figure 8 This is a conceptual diagram for explaining the heat removal method of this embodiment.

[0080] A vent hole 114 is formed in the center of the backing plate 102. Air A1 (first gas) flows from the bottom surface of the backing plate 102 through the vent hole 114 into the chuck space CS. The air A1 is radially dispersed in the chuck space CS and discharged from the outer edge of the wafer chuck 34 (first passage). Alternatively, the air A1 can be actively supplied from the bottom of the backing plate 102 using a fan, etc. However, in this embodiment, the air A1 is slowly supplied by supplying dry air to the inspection area 40.

[0081] In this embodiment, air A2, serving as a "second gas," is further introduced into an air purge inlet 110 located on the side of the backing plate 102. Air A2 is compressed air. Air A2 introduced from the air purge inlet 110 is guided to the center of the backing plate 102 through an air purge passage 112 formed within the backing plate 102. It is then ejected from multiple ejection holes 116 formed around the vent holes 114 into the chuck space CS (the second passage). The high velocity of air A2 during injection creates a negative pressure.

[0082] When air A2 is ejected from radially arranged outlet holes 116, the negative pressure of air A2 draws in air A1, promoting the removal of high-temperature air. In other words, it promotes heat removal from wafer W. Exhaust holes 116 are positioned directly below center portion 106 of wafer W. Therefore, the synergistic effect of air A1 and air A2 significantly enhances the heat removal effect from center portion 106. Furthermore, as mentioned above, a fan (not shown) can be used to assist in the inflow of air A1 from the lower surface of backing plate 102.

[0083] Figure 9 It is a cross-sectional view of the wafer chuck 34 according to this embodiment.

[0084] A heater 118 for heating the wafer W is built into the top plate 100. A suction pipe 122 is formed above the heater 118. A plurality of suction holes 120 are formed on the surface of the top plate 100, and the suction holes 120 communicate with the suction pipe 122. A suction unit, described later, draws air A3 from the suction pipe 122. The suction force from the suction holes 120 causes the wafer W to be attracted to the top plate 100.

[0085] Air A1 flows from the vent holes 114 of the back plate 102 to the back of the top plate 100. The vent holes 114 of the air A1 have a larger flow rate than the air purge passage 112. The air A2 and the air A1 together move the high-temperature air in the chuck space CS toward the outer edge of the wafer chuck 34 ( Figure 9 X-axis direction).

[0086] The aforementioned air purge passage 112 is formed inside the backing plate 102. High-pressure air A2 supplied from the air purge inlet 110 to the air purge passage 112 is ejected from the discharge port 116 into the chuck space CS. Air A2 is supplied when the temperature conditions described below are met, and removes high-temperature air along with air A1.

[0087] Figure 10 yes Figure 9 An enlarged view of the area near the discharge hole 116 in FIG.

[0088] The air A2 ejected from the discharge hole 116 merges with the air A1 flowing in the chuck space CS. The air purge passage 112 is formed in such a way that the convergence angle A formed by the moving direction of the air A1 and the moving direction of the air A2 becomes an acute angle. The convergence angle A is set to an acute angle so that the moving directions of the air A1 and the air A2 are consistent. Therefore, when the air A2 is ejected from the discharge hole 116, the air A1 is smoothly introduced by the negative pressure generated by the air A2. Due to the flow-promoting effect of the air A2 on the air A1, the high-temperature air retained in the chuck space CS is forcefully squeezed out. Compared with the air A1, the air A2 is a small amount, high pressure, and flows intermittently. When the air A2 is ejected, the high-temperature air that is easily retained in the center part of the top plate 100 is forcefully expelled.

[0089] Figure 11 is a schematic diagram showing the set points of the temperature sensors.

[0090] Temperature sensors are installed at two points: point P1 (first point) near the center of top plate 100 and point P2 (second point) near the outer edge. These temperature sensors are existing components such as resistance temperature detectors or thermocouples. Hereinafter, the temperature measured at point P1 is referred to as the "center temperature (first temperature)," and the temperature measured at point P2 is referred to as the "outer edge temperature (second temperature)."

[0091] The air A2 is supplied to the air purge introduction portion 110 when either of the following two temperature conditions is satisfied.

[0092] Temperature condition 1: Central temperature + outer edge temperature > threshold T1 (first threshold)

[0093] Temperature condition 2: Central temperature > outer edge temperature + threshold T2 (second threshold)

[0094] The first and second thresholds can be set arbitrarily by the user. For example, threshold T1 can be "(set temperature + 1) * 2 degrees Celsius" and threshold T2 can be "1 degree Celsius." The set temperature is arbitrary, but can also be set to 100 degrees Celsius, for example, for high-temperature inspections.

[0095] For temperature condition 1, for example, if the set temperature is 100°C, the center temperature is 103°C, and the outer temperature is 100°C, then threshold T1 is (100 + 1) * 2 = 202°C. At this point, center temperature + outer temperature = 203°C, so temperature condition 1 is met and air A2 is injected.

[0096] Temperature condition 1 indicates a situation where the entire wafer W is at a high temperature. Temperature condition 2 indicates a situation where heat remains in the center portion 106 of the wafer W.

[0097] Figure 12 This is a system configuration diagram related to temperature control of the wafer chuck 34 .

[0098] The inspection unit 124 performs wafer inspection on the wafer W placed on the top plate 100. Specifically, the inspection unit 124 corresponds to the test head 44, the elastic frame 54, the pogo pins 68, the probe card 64, the probes 65, and the control unit 20 that controls them.

[0099] The suction unit 134 draws air A3 from the suction pipe 122 of the top plate 100. The ejection unit 164 delivers air A2 from the air purge inlet 110 of the back plate 102. The temperature measurement unit 126 measures the center temperature and the outer edge temperature. The cooling control unit 128 determines whether the temperature condition is met based on the two temperatures measured by the temperature measurement unit 126. The cooling control unit 128 is part of the control unit 20. If either of the two temperature conditions is met, the cooling control unit 128 instructs the ejection unit 164 to eject air A2.

[0100] Figure 13 1 is a flowchart showing a processing procedure for controlling the delivery of the air A2.

[0101] Figure 13 The processing shown is repeated periodically, for example, every second, by the cooling control unit 128 during the high temperature inspection. As described above, air A1 is constantly supplied. The temperature measuring unit 126 measures the central temperature and the outer edge temperature (S10). The cooling control unit 128 determines whether either of the two temperature conditions is met (S12). If neither temperature condition is met (N in S12), the subsequent processing is skipped. If either temperature condition is met (Y in S12), the cooling control unit 128 instructs the injection unit 164 to inject air A2, and the injection unit 164 injects air A2 from the air purge inlet 110 (S14).

[0102] [Summarize]

[0103] In the above, according to the embodiment, the prober 1 has been described focusing on the temperature control system of the wafer chuck 34 .

[0104] By injecting air A2 into the air flow of air A1, the fluidity of air A1 is enhanced. By actively removing high-temperature air from the back side of top plate 100, the temperature of wafer W is easily reduced. In particular, radially forming discharge holes 116 in the center of back plate 102 allows for efficient heat removal from center portion 106 of wafer W.

[0105] The cooling control unit 128 instructs the injection of air A2 when the entire wafer W is at a high temperature (temperature condition 1) or when the center 106 of the wafer W is hotter than the outer edge 108 (temperature condition 2). Since air A2 is not injected constantly but only when heat removal is highly necessary, the power consumption associated with controlling air A2 can be kept to a minimum. The injection unit 164 can also generate high-pressure air A2 by compressing a portion of the dry air supplied to the inspection area 40. Since additional equipment for air A2 is virtually unnecessary, equipment size can be minimized.

[0106] Air A2 removes the hot air by itself, but its main purpose is to promote the fluidity of air A1. Since air A2 generates negative pressure near the discharge hole 116, air A1 and air A2 merge, which can promote the removal of hot air.

[0107] Furthermore, the present invention is not limited to the above-described embodiments or variations, and the constituent elements may be modified and concretized within the scope of the present invention. Various inventions may also be formed by appropriately combining multiple constituent elements disclosed in the above-described embodiments or variations. Furthermore, some constituent elements may be deleted from all the constituent elements shown in the above-described embodiments or variations.

[0108] [Modification]

[0109] In this embodiment, air A1 is described as gas generated by the natural flow of dry air supplied to the inspection area 40. As a modification, a "blower" such as a fan may be provided below the vent 114 to actively supply air A1.

[0110] In the present embodiment, the air A1 and the air A2 are described as air, but the air A1 and the air A2 may be gases other than air, such as hydrogen and nitrogen.

[0111] The spray unit 164 can also supply air A2 based on conditions other than temperature. For example, the spray unit 164 can be configured to continuously supply air A2 for a specified period during the high-temperature inspection, such as 10 seconds before the end of the high-temperature inspection. Alternatively, the temperature measurement unit 126 notifies the user of the temperature distribution of the wafer W, and the user can instruct the spray unit 164 to spray air A2 from the operation panel 22 as needed.

[0112] The cooling control unit 128 may spray air A2 when the temperature inside the inspection area 40 becomes above a predetermined threshold value instead of the temperature of the wafer W. The temperature condition can be arbitrarily set based on various temperature combinations such as central temperature / outer temperature, (central temperature - outer temperature) / outer temperature, {(central temperature + outer temperature) / 2} - inner temperature, etc. In addition, temperature conditions based on the rate of decrease of these temperatures per unit time can be set in addition to the central temperature, outer temperature, and inner temperature themselves. For example, when the difference between the rate of decrease of the outer temperature per second and the rate of decrease of the central temperature per second is greater than a predetermined threshold value, in other words, when the temperature decrease of the central temperature is significantly slower than that of the outer temperature, the temperature condition can be set to be satisfied. Various thresholds related to the temperature condition can be freely set by the user through the operation panel 22.

[0113] The temperature sensor provided on the wafer chuck 34 may be one. For example, the temperature condition may be established when the temperature measured by the single temperature sensor is above a predetermined threshold. The temperature sensors may also be three or more. The user may also set arbitrary temperature conditions based on a combination of multiple temperatures (measured values).

[0114] Next, Modifications 1 to 5 of the temperature control method for the wafer chuck 34 will be described.

[0115] <Variation 1>

[0116] Figure 14 This is a cross-sectional view of a wafer chuck 34 according to Modification 1.

[0117] In Modification 1, a chuck base 136 for supporting the backing plate 102 is connected to the lower surface of the backing plate 102. A chuck space CS1 is formed between the top plate 100 and the backing plate 102, and a chuck space CS2 is formed between the backing plate 102 and the chuck base 136.

[0118] A vent hole 154 is formed in the center of the chuck base 136, communicating with the vent hole 114 of the backing plate 102. In Modification 1, the air purge passage 112 is formed in the chuck base 136, not in the backing plate 102. Air A1 flows through both the chuck space CS1 and the chuck space CS2. Air A2 is ejected from the discharge hole 116, removing heat from the chuck space CS2. As shown in Modification 1, the air purge passage 112 may also be formed in a structure other than the backing plate 102. The air purge passage 112 may also be formed in both the backing plate 102 and the chuck base 136.

[0119] In the first modification, Figure 8 In the same manner as shown, a plurality of discharge holes 116 are radially arranged around the vent hole 154 .

[0120] <Variation 2>

[0121] Figure 15 This is a cross-sectional view of a wafer chuck 34 according to Modification 2.

[0122] In Modification 2, a portion of the air A1 is sucked in by a suction pipe 138 formed on the back plate 102 through a "suction unit" (not shown). When the temperature condition is met, the cooling control unit 128 instructs the suction unit to suck in the air A1. At this time, a portion of the air A1 flowing in the chuck space CS is sucked into the suction pipe 138 through the suction hole 140. The suction pipe 138 is constructed so that the angle B formed by the movement direction of the air A1 flowing in the suction pipe 138 and the movement direction of the air A1 flowing in the chuck space CS is an acute angle. By sucking in a portion of the air A1, the high-temperature air stagnant in the chuck space CS can be efficiently removed.

[0123] In the second modification, Figure 8 In the same manner as shown, a plurality of suction holes 140 are radially arranged around the vent hole 114 .

[0124] <Variation 3>

[0125] Figure 16 This is a cross-sectional view of the wafer chuck 34 in Modification 3.

[0126] In Modification 3, air purge passage 112 is formed inside top plate 100, not in back plate 102. Furthermore, a chuck space CS is formed inside top plate 100 above heater 118. In Modification 3, top plate 100 and back plate 102 can be in close contact. A communication hole 156 is formed in the center of top plate 100, communicating with vent 114. Air A1 supplied from vent 114 removes the high-temperature air in chuck space CS above heater 118.

[0127] When the temperature condition is met, the cooling control unit 128 instructs the ejection unit 164 to eject air A2. When the ejection unit 164 ejects air A2, the air A2 is ejected from the ejection hole 116 located above the heater 118 and merges with the air A1, thereby promoting the flow of the air A1.

[0128] In the second modification, a plurality of discharge holes 116 are radially arranged around the vent hole 114 and the communication hole 156 .

[0129] Figure 17 This is an external view of the back surface of the top plate 100 in Modification 3. Figure 18 yes Figure 17 Magnified view of the central part.

[0130] As described above, in the third modification, the upper portion of the heater 118 ( Figure 17A chuck space CS is formed on the positive Z-axis side of the top plate 100. Furthermore, a plurality of radial grooves 142 are radially formed on the back surface of the top plate 100. Compressed air A2 supplied from the air purge passage 112 is directed into a circular groove 144 located in the center of the top plate 100. The circular groove 144 is shielded by a cover 150, and the air A2 flowing through the circular groove 144 flows into the plurality of radial grooves 142. Figure 18 The internal structure of the circular groove 144 is shown when the cover 150 is removed.

[0131] The air A2 flows toward the outer edge along the plurality of radial grooves 142, and the high-temperature air in the chuck space CS is quickly exhausted. In the third modification, the chuck space CS is formed above the heater 118 as a heat source, thereby further improving the heat removal effect.

[0132] <Variation 4>

[0133] Figure 19 This is an external view of the surface of the back plate 102 in Modification 4.

[0134] In Modification 4, a large circular groove 144 is formed around the vent hole 114 of the back plate 102. This circular groove 144 forms a plurality of radial grooves 152. Radial grooves 152 are simply slits that direct air A2 toward the outer edges. In Modification 4, air A2 is introduced into the circular groove 144 and then directed into the plurality of radial grooves 152, where it is discharged radially.

[0135] Figure 20 4 is a cross-sectional view of a wafer chuck 34 in a fourth modification.

[0136] A first circular plate 170 is provided above the circular groove 144, partially covering the circular groove 144. A large second circular plate 174 is also provided above the first circular plate 170, covering the entire circular groove 144. Both the first circular plate 170 and the second circular plate 174 are annular components centered on the vent hole 114.

[0137] The first circular disk 170 and the second circular disk 174 are used to move the air A2 flowing in the circular groove 144 in the radial direction ( Figure 20 The air A2 flowing in the circular groove 144 is ejected from the top of the circular groove 144 and then changes to the radial direction through the first circular disc 170 and the second circular disc 174 to facilitate movement. Figure 19 As described above, since the plurality of radial grooves 152 are formed on the side surface of the circular groove 144 , the air A2 is guided not only toward the first circular disk 170 and the second circular disk 174 but also toward the radial grooves 152 , thereby promoting the discharge of the high-temperature air A1 .

[0138] <Variation 5>

[0139] Figure 21 4 is a cross-sectional view of a wafer chuck 34 in Modification 5.

[0140] In variant 5, if it is related to Figure 19 As described above, a circular groove 144 is formed on the back surface of the back plate 102. The back plate 102 of Modification 5 does not require radial grooves 152, but radial grooves 152 may be formed therein. A first circular plate 158 and a second circular plate 160 are provided above the circular groove 144 to partially shield the circular groove 144. Both the first circular plate 158 and the second circular plate 160 are annular members centered on the vent hole 114.

[0141] The first circular disk 158 and the second circular disk 160 form a discharge groove 162 on the upper portion of the circular groove 144. The high-pressure air A2 flowing in the circular groove 144 is discharged upward from the discharge groove 162 ( Figure 21 Air A2 is ejected in the positive Z-axis direction. A circular deflecting member 176 is provided on the back of the top plate 100, aligned with a position above the ejection groove 162. The deflecting member 176 functions as a "wind direction adjustment mechanism" that guides the air A2 blown up from the ejection groove 162 in the radial direction. The air A2 flowing through the circular groove 144 is blown upward from the ejection groove 162 and then guided radially by the deflecting member 176, thereby promoting the discharge of high-temperature air from the chuck space CS.

[0142] In the structures of Modification 4 and Modification 5, not only the curved Figure 9 The acute-angled air purge passage 112 shown in the figure can also be adjusted in wind direction by means of external items such as the first circular disk 158, which has the advantage of being easy to manufacture.

[0143] The air A2 flowing through the circular groove 144 flows toward the outer edge from the plurality of radial grooves 152. It is preferable that the flow velocity of the air A2 at the inlet of all the radial grooves 152 is uniform.

[0144] As a modified example, the flow rate of air A2 within the multiple radiating slots 152 may not necessarily be uniform. For example, due to individual differences between wafers W or wafer chuck 34, it is possible that a certain location Q1 on wafer W is more likely to reach higher temperatures than another location Q2. In this case, by enlarging the inlet of the radiating slots 152 near location Q1, the high-temperature air near location Q1 can be more effectively removed than that at location Q2. In this way, the size of the inlet of the radiating slots 152, the length of the radiating slots 152, the slot width, and other factors can be adjusted based on the expected temperature distribution of the wafer W.

[0145] [Explanation of Reference Numerals]

[0146] 1 probe, 2 housing, 4 loading door, 10 measurement area, 12 loading area, 14 storage area, 15 transfer area, 16 wafer storage part, 18 card storage part, 20 control part, 22 operation panel, 24 transfer unit, 26 arm, 30 measurement part, 32 alignment device, 34 wafer chuck, 36 partition wall, 38 partition wall, 39 partition wall, 40 inspection area, 42 machine storage area, 44 test head, 46 opening part, 48 shutter, 54 elastic frame, 56 discharge part, 58 discharge part, 60 discharge part, 62 head stage, 64 probe card, 65 probe, 66 mounting hole, 68 spring pin, 70 sealing ring, 72 sealing ring, 74 suction device, 76 X stage, 78 Y stage, 80 Z stage, 82 card sealing rubber, 100 top plate, 102 back plate, 1 04 spacer, 106 center portion, 108 outer edge portion, 110 air purge inlet portion, 112 air purge passage, 114 ventilation hole, 116 discharge hole, 118 heater, 120 suction hole, 122 suction tube, 124 inspection portion, 126 temperature measurement portion, 128 cooling control portion, 132 first delivery portion, 134 suction portion, 136 chuck base, 138 suction tube, 140 suction hole, 142 radiation groove, 144 circular groove, 150 cover, 152 radiation groove, 154 ventilation hole, 156 connecting hole, 158 first circular disk, 160 second circular disk, 162 discharge groove, 164 injection portion, 170 first circular disk, 174 second circular disk, 176 deflection component, A1 air, A2 air, A3 air, CS chuck space, W wafer.

Claims

1. A detector comprising: a support member that supports the wafer and includes a first passage through which a first gas can pass and a second passage that merges with the first passage; an inspection unit that inspects electrical characteristics of semiconductor devices formed on the wafer when the wafer is placed on the support member; an injection unit for injecting a second gas into the second passage; and The cooling control unit instructs the injection unit whether to inject the second gas.

2. The detector according to claim 1, The second passage is configured to merge obliquely with the first passage.

3. The detector according to claim 1, The second passage includes a plurality of passages that radially discharge the second gas from a central portion toward an outer edge portion of the support member.

4. The detector according to claim 1, The cooling control unit instructs injection of the second gas when a predetermined temperature condition is satisfied.

5. The detector according to claim 4, The device further includes a temperature measuring unit configured to measure a temperature at a first location on the wafer as a first temperature and a temperature at a second location on the wafer that is closer to an outer edge than the first location as a second temperature. The cooling control unit instructs injection of the second gas when a predetermined relationship between the first temperature and the second temperature is satisfied as the temperature condition.

6. The detector according to claim 5, The cooling control unit instructs injection of the second gas when, as the temperature condition, the total value of the first temperature and the second temperature is equal to or greater than a first threshold value.

7. The detector according to claim 5, As the temperature condition, the cooling control unit instructs injection of the second gas when the first temperature is equal to or higher than a value obtained by adding a second threshold value to the second temperature.

8. The detector according to claim 1, The support member includes a top plate on which the wafer is placed and a back plate supporting the top plate. The first passage is formed as a gap between the top plate and the back plate. The second passage is formed inside the back plate, The junction of the second passage and the first passage is configured as a discharge hole extending from the back plate toward the top plate.

9. The detector according to claim 8, The top plate or the back plate includes a wind direction adjustment mechanism for guiding a portion of the second gas to an outer edge side of the top plate.

10. The detector according to claim 1, The support member includes a top plate on which the wafer is placed, a back plate supporting the top plate, and a chuck base supporting the back plate. The first passage is formed as a gap between the backing plate and the chuck base. The second passage is formed inside the chuck base, The junction of the second passage and the first passage is configured as a discharge hole extending from the chuck base toward the backing plate.

11. The detector according to claim 1, The support member includes a top plate on which the wafer is placed and a back plate supporting the top plate. The top plate has a built-in heater, The first passage is formed in the top plate as a gap relative to the surface on which the heater is formed. The second passage is formed inside the top plate, The second passage merges with the first passage at a point extending from the top plate toward the discharge hole of the heater.

12. The detector according to claim 1, The device further includes an air supply unit configured to supply the first gas to the first passage.

13. A detector comprising: a support member that supports the wafer and includes a first passage through which a first gas can pass and a second passage that merges with the first passage; an inspection unit for inspecting electrical characteristics of a semiconductor device formed on the wafer when the wafer is placed on the support member; a suction unit for sucking the first gas from the second passage; as well as The cooling control unit instructs the suction unit whether to suction the first gas.

14. A wafer cooling method, In a prober that supports a wafer by a support member and inspects the electrical characteristics of a semiconductor device formed on the wafer, The support member includes a first passage through which a first gas can pass and a second passage merging with the first passage. This wafer cooling method performs: determining whether the second gas can be sprayed into the second passage according to the temperature of the wafer; and A step of injecting the second gas into the second passage when injection of the second gas is permitted.

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