Prober

Abstract

To provide a prober which can prevent condensation on a wafer and the like while suppressing the consumption of dry gas.SOLUTION: A prober 1 inspects electrical characteristics of a semiconductor device formed on a wafer. The prober 1 comprises: a plurality of areas 40, 42, and 15 which have different set dew points for preventing condensation; a supply part 100 which supplies dry gas to each of the plurality of areas; and a control part 20 which controls the supply of the dry gas carried out by the supply part 100. The control part 20 controls the supply of the dry gas to each of the areas so that each of the set dew points of the plurality of areas 40, 42, and 15 may be achieved.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a prober for testing devices formed on a wafer. [Background technology]

[0002] Wafers on which many devices have been formed in the pre-processing of semiconductor manufacturing are divided into multiple chips for each device in the dicing process. Prior to this dicing process, probing is performed to remove defective devices from among the devices on the wafer. Probing is a wafer-level inspection that identifies defective devices by inspecting the electrical characteristics of the devices formed on the wafer. The equipment that performs this probing is called a prober (see Patent Document 1).

[0003] The prober is equipped with a probe card having multiple probes. The probes are electrically connected to a test head. By bringing the wafer into contact with the probe card, each probe comes into contact with the electrode pad of each device. Electrical signals are sent from the test head to each device via the probes, and their electrical characteristics are inspected to determine whether they are defective.

[0004] In recent years, with the increasing size and integration of wafers, the number of devices formed per wafer has also increased. Therefore, improving testing efficiency is required to improve throughput and reduce costs in semiconductor manufacturing. To address this issue, so-called multi-stage probers have been proposed, which have multiple stages, each with multiple test heads arranged horizontally. Such probers enable multiple test beds to perform testing simultaneously and continuously, thereby improving testing efficiency. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-49989 Summary of the Invention [Problem to be solved by the invention]

[0006] The probing described above is performed in consideration of the actual usage environment to ensure the functionality of the device, so depending on the device specifications, it may be performed in a low-temperature environment. In such cases, measures are taken to lower the dew point by purging the testing area with dry air to prevent damage to the device due to condensation.

[0007] However, condensation must be prevented in areas other than the inspection area where electrical components are housed. There is also concern that condensation may occur when wafers are unloaded after inspection. Therefore, purging the entire area, including the transport area and other areas, with dry air, not just the inspection area, is an option. However, this would consume a large amount of dry air, resulting in increased costs. This problem is particularly pronounced in multi-stage probers, which have a large number of areas.

[0008] The present invention has been made in view of the above circumstances, and one of its objects is to provide a prober that can prevent condensation on wafers and the like while suppressing the consumption of dry gas. [Means for solving the problem]

[0009] One aspect of the present invention is a prober for inspecting electrical characteristics of semiconductor devices formed on a wafer. The prober includes a plurality of areas each having a different set dew point for preventing condensation, a supply unit for supplying dry gas to each of the plurality of areas, and a control unit for controlling the supply of dry gas by the supply unit. The control unit controls the supply of dry gas to each of the plurality of areas so as to realize the set dew point for each of the plurality of areas. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a prober that can prevent condensation on wafers and the like while suppressing consumption of dry gas. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a prober according to an embodiment. [Figure 2] FIG. 2 is a horizontal cross-sectional view schematically showing the internal structure of the prober. [Figure 3] FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 4 is an enlarged view of part B in FIG. 3. [Figure 5] FIG. 2 is a diagram illustrating a configuration of a measurement unit. [Figure 6] FIG. 10 is a diagram illustrating the operation of the measurement unit. [Figure 7] 10 is a flowchart showing an outline of a probing process. [Figure 8] FIG. 10 is a diagram schematically illustrating the configuration of a prober according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following embodiment and its modifications, substantially the same components are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

[0013] The prober of this embodiment inspects the electrical characteristics of semiconductor devices (also simply referred to as "devices") formed on a wafer. This prober is provided with multiple areas, including an inspection area and a transfer area. To perform probing (wafer-level inspection) in a low-temperature environment, a dew point is preset in each of the multiple areas to prevent condensation (the dew point set in each area is also referred to as a "set dew point").

[0014] When probing is performed, dry air is supplied to each area at a flow rate according to the set dew point. That is, if the set dew points of the areas are different, the lower the set dew point, the higher the purge flow rate of dry air is, and the higher the set dew point, the lower the purge flow rate of dry air is. By supplying just enough dry air according to the set dew point in this way, it is possible to prevent condensation in the prober while saving on the amount of dry air used. The details of this are explained below.

[0015] FIG. 1 is a diagram showing a schematic configuration of a prober according to an embodiment. For convenience of explanation, the left-right direction, front-rear direction, and up-down direction when viewed from the front of the device will be referred to as the X direction, Y direction, and Z direction, respectively. The prober 1 has a housing 2 that is rectangular in both front and plan views. Inside the housing 2 are a measurement area 10 where wafer inspection is performed, and a loader area 12 where wafers and the like are transported to and from the measurement area 10. The loader area 12 includes a storage area 14 that stores wafers and probe cards.

[0016] The storage area 14 is provided with a wafer storage section 16 for storing wafers and a card storage section 18 for storing probe cards. The wafer storage section 16 accepts wafer cassettes such as FOUPs and FOSBs that store multiple wafers. When an operator or robot retrieves a wafer or probe card, they can access the front side of each storage section. A loader door 4 is provided on the side of the housing 2 to allow an operator to enter and exit the loader area.

[0017] The prober 1 is also provided with a control unit 20 and an operation panel 22. The control unit 20 is made up of a general-purpose computer and includes a CPU that executes various arithmetic processes, memory or storage that stores control programs and the like, memory that is used as a work area for storing data and executing programs, an input / output interface, a user interface, etc. The user interface accepts operation inputs from an operator via the operation panel 22. The control unit 20 controls each functional unit (mechanism and device) of the prober 1 in accordance with the control program.

[0018] FIG. 2 is a horizontal cross-sectional view that schematically shows the internal structure of the prober 1. As shown in FIG. The prober 1 has a measurement area 10 and a loader area 12. The measurement area 10 includes an inspection area, which will be described later. The measurement area 10 and the loader area 12 are separated by a partition wall provided inside the housing 2. The loader area 12 includes a storage area 14 and a transfer area 15. A transfer unit 24, which transfers wafers W and probe cards (described later), is movably disposed in the transfer area 15.

[0019] The measurement area 10 is provided with a plurality of measurement units 30 for performing probing (wafer-level inspection) of the wafer W. In this embodiment, a multi-stage prober is used in which three stages are arranged vertically, with four measurement units 30 arranged horizontally, but the number of arrangements and stages can be set as appropriate.

[0020] An alignment device 32 shared by the measurement units 30 on each level is disposed in the measurement area 10. The alignment device 32 detachably supports a wafer chuck 34. The wafer chuck 34 suctions and fixes the wafer W, for example, by vacuum suction, and is attached to and detached from the test head of the measurement unit 30 during the probing process (described in detail below). The alignment device 32 can move between the multiple measurement units 30 arranged horizontally. The wafer chuck 34 can move in the X, Y, and Z directions within the measurement area 10 by operation of the alignment device 32, and can also rotate around the Z-axis (θ direction).

[0021] The transport unit 24 transports wafers W between the wafer storage section 16 and each measurement section 30, and transports probe cards between the card storage section 18 and each measurement section 30. The transport unit 24 includes an arm 26 for receiving and transferring wafers W. An unillustrated suction pad is provided on the upper surface of the arm 26. The arm 26 holds the wafer W by vacuum-adhering the backside of the wafer W with this suction pad. The transport unit 24 is a transport device shared by all the measurement sections 30, and is movable in the X and Z directions by the operation of a drive mechanism (unillustrated), and can also rotate around an axis in the Z direction (θ direction).

[0022] The transfer unit 24 moves the arm 26 back and forth (extends and retracts) by operating an arm drive mechanism (not shown). The wafer W in the wafer storage section 16 is taken out by the arm 26 and transferred to each measurement section 30 by the transfer unit 24. After inspection, the wafer W is returned to the wafer storage section 16 from each measurement section 30 by following the reverse route.

[0023] Fig. 3 is a cross-sectional view taken along the line AA in Fig. 2. Fig. 4 is an enlarged view of part B in Fig. 3. As shown in FIG. 3, the measurement area 10 is provided with three measurement sections 30 arranged vertically. Each measurement section 30 is divided into an inspection area 40 and an equipment accommodating area 42 by a partition wall 36. The inspection area 40 is an area where the wafer W to be inspected is placed, and is located relatively lower. The equipment accommodating area 42 is an area where a test head 44 and other electrical equipment are accommodated, and is located relatively higher. The inspection area 40 is divided from the transfer area 15 by a partition wall 38, and the equipment accommodating area 42 is divided from the transfer area 15 by a partition wall 39. The equipment accommodating area 42 and the transfer area 15 correspond to an "outer area" that is divided separately from the inspection area 40.

[0024] 4, 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 with 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 be advanced into the inspection area 40. In other words, the wafer W can be transferred between the transfer unit 24 and the alignment device 32.

[0025] 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 probing is performed in a low-temperature environment, the coolant is supplied to the wafer chuck 34 through the pipe 52. This allows the wafer W placed on the wafer chuck 34 (i.e., the devices formed on the wafer W) to be cooled.

[0026] Meanwhile, a test head 44 and electrical equipment (not shown) are disposed in the equipment housing area 42. A pogo frame 54 is disposed at the boundary between the inspection area 40 and the equipment housing area 42. The pogo frame 54 functions as an interface connecting the test head 44 and a probe card (described later).

[0027] Each area is provided with an outlet that discharges dry air to prevent condensation. An outlet 56 is provided in the inspection area 40, and an outlet 58 is provided in the equipment housing area 42. An outlet 60 is also provided in the transfer area 15. The dew point required to prevent condensation differs depending on the area. For this reason, a set dew point is set for each area, and the supply of dry air is controlled according to that set dew point; details of this will be described later.

[0028] Fig. 5 is a diagram showing the configuration of the measurement unit 30, and corresponds to a cross section taken along the CC arrow in Fig. 4. Fig. 6 is a diagram showing the operation of the measurement unit 30. 5, the measurement unit 30 includes a wafer chuck 34, a test head 44, a pogo frame 54, a head stage 62, and a probe card 64. The probe card 64 has a number of probes 65 for supplying power to the wafer W.

[0029] The pogo frame 54 and head stage 62 form part of the partition wall 36. The head stage 62 is supported by the support member 35. A complementary (circular) mounting hole 66 for mounting the pogo frame 54 is provided in the center of the head stage 62. The mounting hole 66 is closed when the pogo frame 54 is fitted into the mounting hole 66. The head stage 62 has an adsorption surface capable of adsorbing the pogo frame 54, and the pogo frame 54 is adsorbed and fixed by operating a suction device (e.g., a vacuum pump) (not shown). The boundary between the head stage 62 and the pogo frame 54 is kept airtight. In a modified example, the head stage 62 and the pogo frame 54 may be fixed by a fixing structure such as a screw.

[0030] 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, and during testing, supplies test signals (electrical signals) to each device on the wafer W and detects the output signals from each device to obtain its electrical characteristics, thereby testing whether each device is operating normally.

[0031] The pogo frame 54 has a large number of pogo pins 68 that electrically connect terminals formed on the lower surface (opposing surface to the pogo frame 54) of the test head 44 with terminals formed on the upper surface (opposing surface to the pogo frame 54) of the probe card 64. In addition, seal rings 70 and 72 are provided on the peripheries of the upper surface (opposing surface to the test head 44) ​​and the lower surface (opposing surface to the probe card 64) of the pogo frame 54, respectively.

[0032] By operating the suction device 74 (e.g., a vacuum pump), the pressure in the space surrounded by the test head 44, the pogo frame 54, and the seal ring 70 and the space surrounded by the probe card 64, the pogo frame 54, and the seal ring 72 is reduced, thereby integrating the test head 44, the pogo frame 54, and the probe card 64.

[0033] With this configuration, an inner space (i.e., the testing area 40) is partitioned by the partition wall 36 including the head stage 62 and the pogo frame 54, and an outer space (i.e., the equipment accommodating area 42). In this embodiment, the probe card 64 may be removed from the pogo frame 54 when it is replaced, but the seal ring 70 still functions at that time, so that the airtightness between the testing area 40 and the equipment accommodating area 42 is maintained.

[0034] The probe card 64 has a plurality of probes 65 corresponding to the electrodes of each device on the wafer W to be tested. When the test head 44, pogo frame 54, and probe card 64 are integrated as described above, each probe 65 is electrically connected to each terminal of the test head 44 via the pogo frame 54. The probe card 64 has a large number of probes 65 corresponding to the electrodes of all devices on the wafer W to be tested, and the measurement unit 30 simultaneously tests all devices on the wafer W.

[0035] The wafer chuck 34 sucks and fixes the wafer W by operating a suction device (e.g., a vacuum pump) not shown. The wafer chuck 34 is detachably supported by the alignment device 32. The alignment device 32 includes an X table 76, a Y table 78, and a Z table 80.

[0036] A guide rail extending in the X direction is provided in measurement area 10 of housing 2, and X table 76 is installed horizontally so as to be able to move in the X direction along the guide rail. X table 76 is driven by a movement mechanism (not shown). A guide rail extending in the Y direction is provided on the upper surface of X table 76. Y table 78 is installed horizontally so as to be able to move in the Y direction along the guide rail. Y table 78 is driven by a movement mechanism (not shown). Each movement mechanism is realized by a screw feed mechanism and a servo motor that drives it, but may also be realized by a linear motor.

[0037] The Z table 80 is supported by the Y table 78 so that it can move up and down in the Z direction and rotate in the θ direction. The Z table 80 is provided with an elevation mechanism for raising and lowering the wafer chuck 34 and a rotation mechanism for rotating the wafer chuck 34 (not shown). The rotation mechanism is realized by, for example, a spindle motor. The wafer chuck 34 is detachably supported on the upper surface of the Z table 80. With this configuration, the wafer chuck 34 can move in the X direction, Y direction, Z direction, and θ direction. By moving the wafer chuck 34, the wafer W and the probe card 64 can be aligned relative to each other.

[0038] A chuck seal rubber 82 (seal ring) is provided on the upper surface of the wafer chuck 34 so as to surround the wafer W. In the probing process, as shown in FIG. 6, the Z table 80 is moved to move (raise and lower) the wafer chuck 34 toward the probe card 64. At this time, the chuck seal rubber 82 abuts against the lower surface of the probe card 64, thereby forming a space S surrounded by the wafer chuck 34, the probe card 64, and the chuck seal rubber 82. By operating a suction device (e.g., a vacuum pump) not shown, the space S is reduced in pressure, and the wafer chuck 34 is attracted to the probe card 64. As a result, each probe 65 of the probe card 64 abuts against each device on the wafer W, allowing inspection to be performed.

[0039] At this time, by detaching the Z table 80 from the wafer chuck 34 as shown in the figure, the alignment device 32 can be used for another measurement unit 30. As described above, the alignment device 32 is shared by the measurement units 30 at each stage, so while an inspection is being performed at one measurement unit 30, a wafer W can be transferred to another measurement unit 30.

[0040] A heating / cooling structure (not shown) is provided inside the wafer chuck 34. This allows the wafer W to be kept at a high temperature (e.g., 150°C) or a low temperature (e.g., -40°C) to inspect the electrical characteristics of the device. In this embodiment, a double-layer structure consisting of a heating layer of a planar heater and a cooling layer with a coolant passage is used as the heating / cooling mechanism. In a modified example, a single-layer heating / cooling device in which a cooling pipe wrapped around a heater is embedded in a thermal conductor may be used as the heating / cooling mechanism.

[0041] Next, the dew condensation prevention structure in this embodiment will be described in detail. Returning to FIG. 3, the prober 1 supplies (purges) dry gas to each area in order to prevent malfunction or destruction of electronic components and electrical equipment disposed in the housing 2 due to condensation.

[0042] The prober 1 includes 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 path 86, and multiple control valves (on-off valve 94, flow control valves 96-98). The gas supply path 86 connects the discharge port of each area to the dry air supply source 84. The gas supply path 86 branches into a first supply path 88, a second supply path 90, and a third supply path 92 at a branch point P1. The first supply path 88 further branches at a branch point P2 and is connected to the discharge port 56 of the testing area 40 of each measurement unit 30. The second supply path 90 further branches at a branch point P3 and is connected to the discharge port 58 of the equipment housing area 42 of each measurement unit 30. The third supply path 92 is connected to the discharge port 60 of the transfer area 15.

[0043] The dry air supply source 84 has a tank that stores pressurized dry gas. An on-off valve 94 is provided upstream of a branch point P1 in the gas supply path 86, and a flow control valve 96 is provided upstream of a branch point P2 in the first supply path 88. A flow control valve 97 is provided upstream of a branch point P3 in the second supply path 90, and a flow control valve 98 is provided in the third supply path 92. In this embodiment, the on-off valve 94 is a solenoid-driven electromagnetic valve, but may be a motor-driven electrically operated valve. In this embodiment, the flow control valves 96 to 98 are electrically operated valves, but may be solenoid valves.

[0044] The control unit 20 controls the supply of dry gas by the supply unit 100. Prior to the execution of the probing process, the control unit 20 opens the on-off valve 94 and controls the valve opening degree of each of the flow control valves 96 to 98 based on the set dew point of each area. This controls the flow rate of the dry air supplied to each area, bringing it closer to the set dew point.

[0045] Specifically, the lowest temperature that can be reached in each area during probing is defined as the "required dew point." If each area is filled with normal air (atmospheric air), condensation is expected to occur if the temperature in the area falls below the required dew point. Therefore, a "set dew point" is predefined for each area, a temperature that is a predetermined temperature lower than the required dew point. To reliably prevent condensation, a margin is provided for the set dew point. This predetermined temperature (also called the "dew point margin") can be appropriately set for each area depending on the installation environment of the prober 1, temperature change factors due to the amount and time of dry gas inflow and outflow, etc. Alternatively, the dew point in the installation environment can be fed back using a dew point sensor (not shown) installed in the installation environment, and the inflow and outflow amounts can be controlled to appropriately set the set dew point for each area. The set dew point is set lower than the required dew point by the dew point margin.

[0046] In the inspection area 40, it is particularly necessary to prevent condensation on the devices on the wafer W, and during probing, the wafer W is cooled to -40°C based on the device specifications. As described above, this temperature is achieved by cooling the wafer chuck 34 with a coolant. The required dew point in the inspection area 40 is -40°C, but because the dew point is likely to rise due to the opening and closing of the shutter 48, a dew point margin of 10°C is set, and the set dew point is set to -50°C.

[0047] Since the test head 44 and other electrical equipment are placed in the equipment housing area 42, it is necessary to prevent condensation on these, but there is heat conduction and heat transfer from the inspection area 40. For this reason, it is assumed that the minimum temperature will reach -5°C. On the other hand, since the equipment housing area 42 does not have shutters that open and close like the inspection area 40, the rise in dew point is small. Therefore, although the required dew point for the equipment housing area 42 is -5°C, a dew point margin of 5°C is set, and the set dew point is set to -10°C.

[0048] The transfer area 15 has few electrical components, but it is necessary to prevent condensation from occurring in the process of transferring the wafers W after inspection. Considering the installation environment of the prober 1, the minimum temperature in the transfer area 15 is expected to be +15°C. On the other hand, since the transfer area 15 has a larger volume than the inspection area 40 and the equipment housing area 42, it is thought that the dew point is likely to rise. For this reason, although the required dew point in the transfer area 15 is +15°C, a dew point margin of 10°C is set, and the set dew point is set to +5°C.

[0049] When performing the probing process, the control unit 20 controls the opening of the flow control valves 96 to 98 so as to realize the set dew point set for each area, and controls the flow rate of the dry air supplied to each area.

[0050] FIG. 7 is a flowchart showing an outline of the probing process. In the probing process, the control unit 20 sets the flow rate of dry air to be supplied to each area based on the set dew point of each area (S10), then opens the on-off valve 94 to start the supply of dry air (S12), and controls the valve opening of each of the flow control valves 96 to 98 to control the flow rate of dry air to be supplied to each area (S14).

[0051] Then, when the set time has elapsed by which the dew point in each area is expected to reach the set dew point (Y in S16), the control unit 20 starts cooling the wafer chuck 34 (S18) and then starts probing (S20). This "set time" is set in advance through experiments, etc.

[0052] As described above, in this embodiment, different set dew points are set for the inspection area 40, the equipment housing area 42, and the transfer area 15. When probing is performed, dry air is supplied to each area at a flow rate corresponding to the set dew point. That is, by supplying each area with the necessary and sufficient amount of dry air corresponding to the set dew point, it is possible to prevent condensation in each area while suppressing dry air consumption.

[0053] Furthermore, by supplying dry air to multiple separate areas, the independence of each area can be ensured. Therefore, although the shutter 48 is opened and closed when loading and unloading wafers W into and from the inspection area 40, this does not significantly affect the environment (temperature, humidity, etc.) within the equipment housing area 42. While workers may open the loader door 4 to enter and exit the transfer area 15 for maintenance of the transfer unit 24, etc., because the inspection area 40 is separated from the transfer area 15, an increase in the dew point in the inspection area 40 can be suppressed. Since there is less need to consider the dew point during maintenance, the ease of maintenance itself is improved.

[0054] Furthermore, by making the inspection area 40 a separate area from the equipment housing area 42, its volume can be kept to a minimum, which allows the dew point to recover quickly after the wafer W is loaded or unloaded, thereby improving the efficiency (throughput) of the probing process.

[0055] Although the preferred embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to this specific embodiment, and various modifications are possible within the scope of the technical concept of the present invention.

[0056] [Variations] FIG. 8 is a diagram schematically illustrating the configuration of a measurement unit of a prober according to a modified example. Although not mentioned in the above embodiment, the observation equipment may be protected (prevented from condensation) during inspection by utilizing the configuration divided into each area. In the prober of this modified example, a dummy test head 144 is placed in one of the multiple equipment housing areas 42, and a microscope 110 is housed in the test head 144. The microscope 110 is an instrument that precisely observes the position of the wafer W on the wafer chuck 34.

[0057] The test head 144 is a housing of the test head 44 without its internal structure, and has an opening for exposing the lens of the microscope 110 downward (toward the wafer W). In order to ensure airtightness between the inspection area 40 and the equipment housing area 42, a transparent (light-transmitting) partition plate is provided in the partition wall 36 at a position corresponding to the lens of the microscope 110.

[0058] With this configuration, the positional accuracy of the wafer W on the wafer chuck 34 can be observed by the microscope 110. The equipment housing area 42 does not have a shutter 48 like the inspection area 40, and is not open to the transfer area 15, so it is possible to suppress the intrusion of the external atmosphere. As a result, there is little change in the dew point within the area, and it is possible to prevent fogging (condensation) of the lens, etc., and it is possible to maintain a stable state of the microscope 110.

[0059] In this modification, a microscope is exemplified as an optical instrument to be housed in the equipment housing area 42, but a camera or other optical instrument may also be housed. Alternatively, a temperature measuring instrument such as a thermosensor that detects the temperature of the wafer W may be placed. Any instrument that performs maintenance on the instruments or components placed in the measurement area 40 may be used. The low dew point space of the equipment housing area 42 can also be used for these instruments.

[0060] [Other variations] In the above embodiment, dry air is used as the dry gas, but a dry inert gas or other dry gas may also be used. Dry air may be supplied to the loader area 12 (transport area 15) that may be accessed by workers, and another dry gas may be supplied to the measurement area 10 (at least one of the inspection area 40 and the equipment housing area 42). The type of dry gas may be varied depending on the set dew point.

[0061] In the above embodiment, an example has been shown in which the flow rate of dry gas supplied to each area is controlled to achieve the set dew point for each area. In a modified example, dry gases (different types of dry gases) with different cooling performance (cooling efficiency) may be supplied depending on the set dew point. That is, dry gas with relatively higher cooling performance may be supplied to an area with a lower set dew point, and dry gas with relatively lower cooling performance may be supplied to an area with a higher set dew point. In this case, the flow rate of dry gas supplied to each area may be the same or different.

[0062] In the above embodiment, a multi-stage prober having a plurality of measurement units 30 is exemplified, but a single-stage prober having a single measurement unit 30 may also be employed. In this case, as in the above embodiment, the control unit controls the flow rate of the dry gas so as to achieve the set dew point for each area.

[0063] In the above embodiment, the countermeasures against condensation on the wafer W have been mainly described, but the probe card 64 is also a consumable item and therefore needs to be replaced at appropriate times. That is, the probe card 64 is also carried in and out of the inspection area 40, but according to the above embodiment, the same condensation prevention effect as for the wafer W can be obtained.

[0064] Although not mentioned in the above embodiment, a structure may be adopted that allows the test head 44 to be pulled out from the equipment housing area 42. For example, a shutter may be provided on the side wall of the partition wall 36 that forms the equipment housing area 42, and the test head 44 may be pulled out horizontally by opening the shutter. With such a configuration, the above-mentioned test head 44 and a dummy test head 144 can be swapped as needed. Furthermore, maintenance of the test head 44 becomes easier. Because the inspection area 40 and the equipment housing area 42 are separate areas, the dew point environment of the inspection area 40 is less affected by the removal and insertion of the test head.

[0065] In the above embodiment, probing in a low-temperature environment has been mainly described, but it goes without saying that inspection can also be performed at multiple temperatures ranging from low to high. Since the shutter 48 is closed after the wafer W has been placed in the inspection area 40, the set temperature of the wafer chuck 34 can be changed without considering heat exchange with the outside air. This makes it easy to perform inspection at multiple set temperatures.

[0066] The present invention is not limited to the above-described embodiments and modifications, and the components can be modified without departing from the spirit of the invention. Various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments and modifications. Furthermore, some components can be omitted from all the components shown in the above-described embodiments and modifications. [Explanation of symbols]

[0067] 1 prober, 2 housing, 4 loader door, 10 measurement area, 12 loader area, 14 storage area, 15 transfer area, 20 control section, 24 transfer unit, 30 measurement section, 32 alignment device, 34 wafer chuck, 35 support member, 36 partition wall, 38 partition wall, 39 partition wall, 40 inspection area, 42 equipment storage area, 44 test head, 48 shutter, 50 heat exchanger, 54 pogo frame, 56 discharge section, 58 discharge section, 60 discharge section, 62 head stage, 64 probe card, 65 probe, 68 pogo pin, 70 seal ring, 72 seal ring, 74 suction device, 82 chuck seal rubber, 84 dry air supply source, 86 gas supply path, 94 on / off valve, 96 flow control valve, 97 flow control valve, 98 flow control valve, 100 Supply section, 110 microscope, 144 test head, W wafer.

Claims

1. A prober for inspecting electrical characteristics of semiconductor devices formed on a wafer, comprising: Multiple areas with different dew points to prevent condensation, a supply unit that supplies a dry gas to each of the plurality of areas; a control unit that controls the supply of dry gas by the supply unit; Equipped with The control unit controls the supply of dry gas to each of the plurality of areas so as to achieve a set dew point for each of the areas.

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

3. 3. The prober according to claim 1, wherein the set dew point is set to be lower than the lowest temperature in the area.

4. the plurality of areas include an inspection area in which the wafer and the probe card are placed, and an outer area that is partitioned separately from the inspection area; 3. The prober according to claim 1, wherein the control unit controls the supply of dry gas to each area based on the dew points set for the inspection area and the outer area.

5. 5. The prober according to claim 4, wherein the outer area includes an equipment housing area in which a test head to which the probe card is connected is disposed.

6. The prober of claim 5 , wherein the dew point setting of the equipment housing area is higher than the dew point setting of the testing area.

7. the outer area includes a transport area that is partitioned separately from the equipment accommodating area and in which a transport device for carrying the wafer into and out of the inspection area is disposed, The prober according to claim 6 , wherein the set dew point of the transfer area is higher than the set dew point of the equipment housing area.

8. the outer area includes a transfer area in which a transfer device for carrying the wafer into and out of the inspection area is disposed, 5. The prober according to claim 4, wherein the set dew point of the transfer area is higher than the set dew point of the inspection area.

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