Detector

Abstract

Provided is a probe capable of suppressing consumption of a dry gas and preventing condensation of a wafer or the like. A probe (1) according to an aspect inspects electrical characteristics of a semiconductor device formed on a wafer. A probe (1) includes: a plurality of regions (40, 42, 15) having different set dew points for preventing condensation; a supply unit (100) for supplying a dry gas to each of the plurality of regions; and a control unit (20) that controls the supply of the dry gas by the supply unit (100). The control unit (20) controls the supply of the drying gas to each of the plurality of regions (40, 42, 15) so as to achieve a set dew point for each of the plurality of regions (40, 42, 15).

Description

Technical Field

[0001] The present invention relates to a probe for inspecting devices formed on a wafer. Background Art

[0002] In the early stages of semiconductor manufacturing, wafers with multiple devices formed on them are separated into multiple chips according to the device in the dicing process. Before this dicing process, probing is performed to remove defective devices from the wafer. Probing is a wafer-grade inspection that identifies defective devices by examining the electrical characteristics of the devices formed on the wafer. The device performing this probing is a prober (see Patent Document 1).

[0003] The prober has 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. An electrical signal is sent from the test head through the probes to each device, and the electrical characteristics are checked 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 Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-49989 Summary of the Invention

[0008] The above inspections are conducted in a low-temperature environment to ensure device functionality, taking into account the actual operating environment. To prevent damage to the device due to condensation, measures such as blowing dry air through the inspection area to lower the dew point are implemented.

[0009] However, areas outside the inspection area, where electrical components are located, also need to prevent condensation. Furthermore, condensation can also occur during wafer transport after inspection. Therefore, one option is to purge not only the inspection area but also other areas, such as the transport area, with dry air. However, this approach consumes a large amount of dry air and increases costs. This problem is particularly pronounced in multi-stage, multi-stage detectors, due to the large number of zones.

[0010] The present invention has been made in view of the above circumstances, and one object of the present invention is to provide a probe that can suppress the consumption of drying gas and prevent dew condensation on a wafer or the like.

[0011] Methods used to solve technical problems

[0012] One embodiment of the present invention is a probe for inspecting the electrical characteristics of semiconductor devices formed on wafers. The probe includes: multiple zones with different set dew points to prevent condensation; a supply unit that supplies dry gas to each of the multiple zones; and a control unit that controls the supply of dry gas from the supply unit. The control unit controls the supply of dry gas to each zone to achieve the set dew point for each zone.

[0013] Effects of the Invention

[0014] According to the present invention, it is possible to provide a probe that can suppress the consumption of drying gas and prevent dew condensation on a wafer or the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram showing a schematic configuration of a detector according to an embodiment.

[0016] Figure 2 It is a horizontal cross-sectional view schematically showing the internal structure of the detector.

[0017] Figure 3 yes Figure 2 A-A arrow cross-section diagram.

[0018] Figure 4 yes Figure 3 Enlarged view of part B.

[0019] Figure 5 It is a diagram showing the configuration of a measuring unit.

[0020] Figure 6 It is a diagram showing the operation of the measuring unit.

[0021] Figure 7 This is a flowchart showing an overview of the detection process.

[0022] Figure 8 It is a diagram schematically showing the structure of a probe according to a modified example. DETAILED DESCRIPTION

[0023] 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.

[0024] The prober of this embodiment inspects the electrical characteristics of semiconductor devices (also referred to simply as "devices") formed on wafers. The prober is equipped with multiple zones, including an inspection zone and a transfer zone. To perform probing (wafer-level inspection) in a low-temperature environment, a dew point is pre-set in each of the multiple zones to prevent condensation (the dew point set for each zone is also referred to as the "set dew point").

[0025] During detection, dry air is supplied to each zone at a flow rate corresponding to the set dew point. Specifically, if the set dew points for each zone differ, the lower the set dew point, the greater the dry air purge flow rate, while the higher the set dew point, the lower the dry air purge flow rate. This method ensures that sufficient dry air is supplied to the detector in accordance with the set dew point, preventing condensation in the detector and conserving dry air. This is described in detail below.

[0026] Figure 1 It is a diagram showing a schematic configuration of a detector according to an embodiment.

[0027] 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.

[0028] 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.

[0029] The storage area 14 is equipped with a wafer storage section 16 for wafers and a card storage section 18 for probe cards. The wafer storage section 16 receives wafer cassettes, such as FOUPs or FOSBs, that hold multiple wafers. Operators or robots can access each storage section from the front to retrieve wafers or probe cards. A loading door 4 is provided on the side of the housing 2 for operators to enter and exit the loading area.

[0030] 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.

[0031] Figure 2 It is a horizontal cross-sectional view schematically showing the internal structure of the probe 1 .

[0032] 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.

[0033] The measurement area 10 is provided with a plurality of measurement units 30 for performing probing (wafer grade inspection) on the wafers W. In this embodiment, a multi-stage prober with three stages arranged vertically is employed, with four measurement units 30 arranged horizontally on each stage. However, the number of stages and the number of arrangement can be set as appropriate.

[0034] The measurement area 10 is equipped with an alignment device 32 that 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, for example, and is then attached to and removed from the test head of the measurement unit 30 during the probing process (details will be described later). The alignment device 32 is movable between the multiple measurement units 30 arranged horizontally. 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 to rotate about the Z axis (θ direction).

[0035] The transfer unit 24 transfers the wafer W between the wafer storage section 16 and each measuring section 30, and transfers the probe card between the card storage section 18 and each measuring section 30. The transfer unit 24 has an arm 26 for transferring the wafer W. A suction disk (not shown) is provided on the upper surface of the arm 26. The arm 26 vacuum-adsorbs the back surface of the wafer W through the suction disk to hold the wafer W. The transfer unit 24 is a transfer device shared by all the measuring sections 30. It can move in the X and Z directions and can rotate around the axis in the Z direction (θ direction) by the operation of a driving mechanism (not shown).

[0036] 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.

[0037] Figure 3 yes Figure 2 A-A arrow cross-section diagram. Figure 4 yes Figure 3 Enlarged view of part B.

[0038] 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.

[0039] 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.

[0040] Furthermore, a heat exchanger 50 for cooling the wafer chuck 34 is provided in the inspection area 40. A pipe 52 for circulating a coolant is connected to the heat exchanger 50. When performing inspection in a low-temperature environment, the coolant is supplied to the wafer chuck 34 via the pipe 52. This cools the wafer W (i.e., the device formed on the wafer W) placed on the wafer chuck 34.

[0041] 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).

[0042] Each area is equipped with a discharge unit that discharges dry air to prevent condensation. Discharge unit 56 is located in the inspection area 40, and discharge unit 58 is located in the equipment storage area 42. Discharge unit 60 is also located in the transfer area 15. The dew point required to prevent condensation varies depending on the area. Therefore, a set dew point is determined for each area, and the supply of dry air is controlled accordingly. Details of this will be described later.

[0043] Figure 5 is a diagram showing the structure of the measuring unit 30, corresponding to Figure 4 C-C arrow section. Figure 6 3 is a diagram showing the operation of the measuring unit 30 .

[0044] like Figure 5As 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.

[0045] The elastic frame 54 and the header platform 62 constitute a part of the partition wall 36. The header platform 62 is supported by the supporting member 35. In the central portion of the header platform 62, a mounting hole 66 of a complementary shape (circular) for mounting the elastic frame 54 is provided. 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 capable of adsorbing the elastic frame 54, and the elastic frame 54 is adsorbed and fixed by operating an suction device (such as a vacuum pump) not shown in the figure. The airtightness of the boundary portion 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] The wafer chuck 34 operates a suction device (eg, a vacuum pump) (not shown) to suck and fix 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.

[0052] A guide rail extending in the X direction is provided in the measurement area 10 of the housing 2. 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, but can also be implemented by a linear motor.

[0053] The Z platform 80 is supported by the Y platform 78 so as to be able to rise and fall in the Z direction and to rotate in the θ direction. A lifting mechanism for raising and lowering the wafer chuck 34 and a rotating mechanism (not shown) for rotating the wafer chuck 34 are provided on the Z platform 80. 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.

[0054] On the upper surface of the wafer chuck 34, a sealing rubber 82 (sealing ring) is provided to surround the wafer W. Figure 6 As shown, Z stage 80 is moved, causing wafer chuck 34 to move (elevate) toward probe card 64. At this point, engagement rubber seal 82 contacts the lower surface of probe card 64, forming a space S surrounded by wafer chuck 34, probe card 64, and engagement rubber seal 82. By activating a suction device (not shown) (e.g., a vacuum pump), the pressure in space S is reduced, and wafer chuck 34 is drawn toward probe card 64. This allows probes 65 of probe card 64 to contact devices on wafer W, enabling inspection.

[0055] At this time, as shown in the figure, by detaching the Z stage 80 from the wafer chuck 34, the alignment device 32 can be used for another measurement unit 30. As described above, the alignment device 32 is common to the measurement units 30 of each stage. Therefore, while one measurement unit 30 is performing inspection, the wafer W can be transferred to another measurement unit 30.

[0056] A heating and cooling mechanism (not shown) is provided inside the wafer chuck 34. Thus, the wafer W can be placed in a high temperature state (e.g., 150°C) or a low temperature state (e.g., -40°C) to inspect the electrical characteristics of the device. In this embodiment, a double-layer structure is used as the heating and cooling mechanism, comprising a heating layer of a surface heater and a cooling layer having a coolant passage. In a modified example, a single-layer heating / cooling device having a cooling tube wound around a heater embedded in a heat conductor can be used as the heating and cooling mechanism.

[0057] Next, the condensation prevention structure in this embodiment will be described in detail.

[0058] return Figure 3 In order to prevent malfunction or damage caused by condensation on electronic components or electrical equipment installed in the housing 2, the detector 1 supplies (purges) dry gas to each area.

[0059] The detector 1 is provided with a supply unit 100 for supplying dry gas to each area. The supply unit 100 includes a dry air supply source 84, a gas supply passage 86, and a plurality of control valves (an on-off valve 94, and flow control valves 96 to 98). The gas supply passage 86 connects the discharge portion of each area with the dry air supply source 84. The gas supply passage 86 branches into a first supply passage 88, a second supply passage 90, and a third supply passage 92 at a branch point P1. The first supply passage 88 further branches at a branch point P2 and is connected to the discharge portion 56 of the inspection area 40 in each measuring unit 30. The second supply passage 90 further branches at a branch point P3 and is connected to the discharge portion 58 of the machine storage area 42 in each measuring unit 30. The third supply passage 92 is connected to the discharge portion 60 of the transmission area 15.

[0060] The dry air supply source 84 includes a tank that stores pressurized dry gas. An on-off valve 94 is provided upstream of branch point P1 in the gas supply passage 86, and a flow control valve 96 is provided upstream of branch point P2 in the first supply passage 88. A flow control valve 97 is provided upstream of branch point P3 in the second supply passage 90, and a flow control valve 98 is provided in the third supply passage 92. While the on-off valve 94 is a solenoid-driven electromagnetic valve in this embodiment, a motor-driven electric valve may also be employed. The flow control valves 96-98 are motor-driven valves in this embodiment, but solenoid valves may also be employed.

[0061] The controller 20 controls the supply of dry gas from the supply unit 100. Before performing the detection process, the controller 20 opens the on-off valve 94 and controls the openings of the flow control valves 96-98 according to the set dew point for each zone. This controls the flow rate of dry air supplied to each zone to approach the set dew point.

[0062] Specifically, regarding the temperature environment during detection, the lowest temperature that can be reached in each area is set as the "necessary dew point". It is assumed that when each area is filled with general air (atmosphere), condensation will occur when the temperature in the area is lower than the necessary dew point. Therefore, a temperature that is a specified temperature lower than the necessary dew point is pre-set as the "set dew point" for each area. In order to reliably prevent condensation, the set dew point can be left with a margin. Regarding this specified temperature (also called "dew point margin"), it can be appropriately set for each area based on the setting environment of the detector 1, the inflow and outflow of the dry gas, or temperature change factors caused by time. In addition, a dew point sensor (not shown) set in the setting environment can also be used to feedback the dew point in the setting environment, control the inflow and outflow, and set it appropriately for each area. The set dew point can also be set to be only a dew point margin lower than the necessary dew point.

[0063] In inspection area 40, while condensation on devices on wafer W must be prevented, wafer W is cooled to -40°C during inspection according to device specifications. As described above, this temperature is achieved by cooling wafer chuck 34 with coolant. The required dew point in inspection area 40 is -40°C, but the dew point tends to rise due to the opening and closing of shutter 48. Therefore, a dew point margin of 10°C is set, resulting in a set dew point of -50°C.

[0064] The equipment storage area 42 houses the test head 44 and other electrical components, which must be protected from condensation. However, heat conduction and heat transfer from the inspection area 40 are present. Therefore, the minimum temperature is assumed to be -5°C. On the other hand, the equipment storage area 42 lacks the opening and closing of switches unlike the inspection area 40, so the dew point rises less. Therefore, when the required dew point is -5°C, the dew point margin is set to 5°C, resulting in a set dew point of -10°C.

[0065] Although transport area 15 contains few electrical components, condensation must be prevented during the transport of wafers W after inspection. Considering the prober 1's installation environment, the minimum temperature in transport area 15 is set at +15°C. However, the transport area 15, due to its larger volume compared to the inspection area 40 or the equipment storage area 42, is believed to be more susceptible to higher dew points. Therefore, if the required dew point in transport area 15 is +15°C, a dew point margin of 10°C is set, resulting in a set dew point of +5°C.

[0066] When executing the detection process, the control unit 20 controls the openings of the flow control valves 96 to 98 so as to realize the set dew point set for each zone, thereby controlling the flow rate of dry air supplied to each zone.

[0067] Figure 7 This is a flowchart showing an overview of the detection process.

[0068] During the detection process, the control unit 20 sets the flow rate of dry air supplied to each zone based on the set dew point of each zone (S10). Next, the on-off valve 94 is opened to start the supply of dry air (S12), and the opening of each flow control valve 96-98 is controlled to control the flow rate of dry air supplied to each zone (S14).

[0069] Then, after the set time (Y in S16 ) for elapse of the estimated dew point in each region, the control unit 20 starts cooling the wafer chuck 34 ( S18 ) and then starts detection ( S20 ). The “set time” is set in advance through experiments or the like.

[0070] As described above, in this embodiment, different set dew points are set for the inspection area 40, the equipment storage area 42, and the transfer area 15. Furthermore, during detection, dry air is supplied to each area at a flow rate corresponding to the set dew point. In other words, by supplying a sufficient amount of dry air to each area at the set dew point, dry air consumption can be reduced and condensation can be prevented in each area.

[0071] Furthermore, the supply of dry air is divided into multiple zones, ensuring the independence of each zone. Therefore, while the shutter 48 opens and closes when transporting wafers W into and out of the inspection area 40, this has minimal impact on the environment (temperature, humidity, etc.) within the machine storage area 42. Operators may open the loading door 4 to enter and exit the transfer area 15 for maintenance on the transfer unit 24, etc. However, since the inspection area 40 is divided into the transfer area 15, the dew point in the inspection area 40 can be suppressed. This reduces the need to consider the dew point during maintenance, thereby improving maintainability.

[0072] Furthermore, by setting the inspection area 40 as a separate area from the machine storage area 42, its volume is kept to the necessary minimum, so that the dew point recovery after the wafer W is carried in or out is also accelerated, and the efficiency (throughput) of the detection process can be improved.

[0073] While preferred embodiments of the present invention have been described above, the present invention is not limited to these specific embodiments, and it goes without saying that various modifications are possible within the scope of the technical concept of the present invention.

[0074] [Modification]

[0075] Figure 8 It is a diagram schematically showing the configuration of a measuring unit of a probe according to a modified example.

[0076] Although not described in the above embodiment, the structure of dividing each area can also be used to protect observation equipment during inspection (to prevent condensation). In the probe of this modified example, a dummy test head 144 is located in a portion of the multiple equipment storage areas 42, and a microscope 110 is housed in the test head 144. Microscope 110 is a device for precisely observing the position of wafer W on wafer chuck 34.

[0077] Test head 144 is a housing obtained by removing the internal structure of test head 44 and has an opening for exposing the lens of microscope 110 downward (toward the wafer W). To ensure airtightness between inspection area 40 and equipment storage area 42, a translucent (light-transmissive) partition plate is provided in partition wall 36 at a position corresponding to the lens of microscope 110.

[0078] This configuration allows the positional accuracy of wafer W on wafer chuck 34 to be observed through microscope 110. Unlike inspection area 40, machine storage area 42 lacks shutter 48, nor does it open to transfer area 15, thereby minimizing the intrusion of external atmosphere. Consequently, the dew point within the area fluctuates minimally, preventing lens fogging (condensation), and maintaining a stable state for microscope 110.

[0079] Furthermore, in this variation, a microscope is shown as an example of an optical device housed in device storage area 42, but other optical devices such as cameras can also be housed. Alternatively, a temperature measuring device such as a thermal sensor for detecting the temperature of the wafer W can be installed. Any device located within measurement area 40 or performing component maintenance can be used. For these devices, the low dew point space of device storage area 42 can also be utilized.

[0080] [Other modifications]

[0081] While the above embodiment uses dry air as the drying gas, other dry gases such as dry inert gas may also be used. Dry air may be supplied to the loading area 12 (transfer area 15) accessible to operators, while another dry gas may be supplied to the measurement area 10 (at least one of the inspection area 40 and the equipment storage area 42). The type of drying gas may also be varied depending on the set dew point.

[0082] The above embodiment shows an example of controlling the flow rate of dry gas supplied to each zone in order to achieve the set dew point for each zone. In a variation, different dry gases (different types of dry gas) with different cooling performance (cooling efficiency) can be supplied according to the set dew point. That is, zones with lower set dew points can be supplied with dry gas with relatively higher cooling performance, while zones with higher set dew points can be supplied with dry gas with relatively lower cooling performance. In this case, the flow rate of dry gas supplied to each zone can be the same or different.

[0083] While the above embodiment illustrates a multi-stage, multi-stage detector equipped with multiple measuring units 30, a single-stage detector with a single measuring unit 30 may also be employed. In this case, as in the above embodiment, the control unit controls the flow rate of the drying gas to achieve the set dew point in each zone.

[0084] While the above embodiment primarily addresses countermeasures against condensation on wafers W, the probe card 64 is also a consumable item and requires timely replacement. Specifically, the probe card 64 is also carried in and out of the inspection area 40. The above embodiment achieves the same condensation prevention effect as the wafers W.

[0085] Although not described in the above embodiment, a structure in which the test head 44 can be pulled out from the machine storage area 42 can also be employed. For example, a shutter can be provided in the side wall of the partition wall 36 forming the machine storage area 42, and the test head 44 can be pulled out horizontally by opening the shutter. With such a structure, the test head 44 and the dummy test head 144 can be replaced as appropriate. In addition, maintenance of the test head 44 is also facilitated. Since the inspection area 40 and the machine storage area 42 are separate areas, even if the test head is moved in and out in this manner, the dew point environment in the inspection area 40 is minimally affected.

[0086] While the above embodiment primarily focuses on detection in a low-temperature environment, it goes without saying that inspection can be performed at multiple temperature levels, from low to high. When wafer W is placed in inspection area 40, shutter 48 closes, allowing the set temperature of wafer chuck 34 to be changed without considering heat exchange with the outside air. This facilitates inspection at multiple set temperatures.

[0087] 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.

[0088] Description of Reference Numerals

[0089] 1. Probe, 2. Housing, 4. Loading door, 10. Measurement area, 12. Loading area, 14. Storage area, 15. Transfer area, 20. Control unit, 24. Transfer unit, 30. Measurement unit, 32. Alignment device, 34. Wafer chuck, 35. Support member, 36. Partition, 38. Partition, 39. Partition, 40. Inspection area, 42. Machine storage area, 44. Test head, 48. Opener, 50. Heat exchanger, 54. Elastic frame, 56. Discharge unit, 58. Discharge unit, 60. Discharge unit, 62. Head stage, 64. Probe card, 65. Probe, 68. Spring pin, 70. Sealing ring, 72. Sealing ring, 74. Suction device, 82. Engaging seal rubber, 84. Dry air supply source, 86. Gas supply path, 94. Open / close valve, 96. Flow control valve, 97. Flow control valve, 98. Flow control valve, 100. Supply unit, 110. Microscope, 144. Test head, W wafer.

Claims

1. A detector for inspecting electrical characteristics of a semiconductor device formed on a wafer, comprising: To prevent condensation, multiple areas with different dew points can be set. a supply unit for supplying dry gas to the plurality of regions respectively, and a control unit for controlling the supply of the drying gas by the supply unit; The control unit controls the supply of the dry gas to each of the plurality of zones so as to achieve a set dew point in each of the plurality of zones.

2. The detector according to claim 1, The control unit controls the flow rate of the dry gas supplied to each zone so as to maintain a set dew point in each zone.

3. The detector according to claim 1 or 2, The set dew point is set lower than the lowest temperature of the area.

4. The detector according to claim 1 or 2, comprising: The plurality of regions include an inspection region where the wafer and the probe card are arranged, and an outer region separately divided from the inspection region. The control unit controls the supply of the dry gas to each area based on a set dew point of each of the inspection area and the outer area.

5. The detector according to claim 4, The outer area includes a machine accommodation area in which a test head connected to the probe card is arranged.

6. The detector according to claim 5, The set dew point of the machine housing area is higher than the set dew point of the inspection area.

7. The detector according to claim 6, As the outer area, a transfer area is provided with a transfer device, which is separated from the machine accommodation area. The transfer device is used to carry the wafer into and out of the inspection area. The set dew point of the transfer area is higher than the set dew point of the machine receiving area.

8. The detector according to claim 4, The outer area includes a transfer area where a transfer device is arranged, and the transfer device is used to carry the wafer into and out of the inspection area. The set dew point of the transfer area is higher than the set dew point of the inspection area.

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