Prober

Abstract

To provide a prober which can prevent dew condensation on a wafer or the like, while reducing consumption of a dry gas.SOLUTION: A prober 1 inspects electrical characteristics of devices formed on a wafer W. The prober 1 comprises: a housing 2 formed with an inspection area 10 at which inspection is performed; a first supply unit for supplying a dry gas to the inspection area 10 entirely; a second supply unit for locally supplying the dry gas to a portion of the inspection area; and a control unit 20 for controlling the dry gas supplied by each supply unit.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 probes. The probes are electrically connected to a tester. By bringing a wafer into contact with the probe card, the probes come into contact with the electrodes of the device. Electrical signals are sent from the tester to the device via the probes, and the electrical characteristics of the device are inspected to determine whether it is defective.

[0004] Probing is performed taking into consideration a variety of operating environments to ensure device functionality. For this reason, testing is required in a variety of temperature environments, from high temperatures (e.g., 150°C) to low temperatures (e.g., -40°C). To meet these requirements, a heating and cooling structure is installed inside the wafer chuck that supports the wafer. When testing in a low-temperature environment, measures are taken to lower the dew point by purging the entire testing area with dry air to prevent device damage due to condensation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-136569 Summary of the Invention [Problem to be solved by the invention]

[0006] The inspection area is equipped with various devices and mechanisms for inspecting, observing, or moving wafers. Therefore, the structure and layout of these devices create confined areas. Moist air tends to accumulate in these confined areas, making it difficult to lower the dew point even when the inspection area is purged with dry air. Therefore, a method is used in which a dew point meter is installed in a location in the confined area where condensation is particularly problematic, and inspection is suspended until the dew point temperature measured by the dew point meter drops below the inspection temperature after the dry air purge begins.

[0007] However, installing a dew point meter in each such small area is costly. Also, extending the purge time to lower the dew point in a specific small area consumes a large amount of dry air, which increases costs. Longer purge times before inspection can also reduce the overall throughput of semiconductor manufacturing.

[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 testing electrical characteristics of devices formed on a wafer, the prober comprising: a housing having a test area where testing is performed, a first supply unit that supplies dry gas to the entire test area, a second supply unit that supplies dry gas locally to a portion of the test area, and a control unit that controls the supply of dry gas by each supply unit. [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] 1 is a perspective view illustrating a schematic configuration of a prober according to an embodiment. [Figure 2] FIG. 2 is a diagram schematically illustrating the internal structure of a prober. [Figure 3] FIG. 2 is a diagram illustrating the configuration of an alignment camera and a heat sink. [Figure 4] 10A and 10B are diagrams illustrating an example of a method for preventing condensation. [Figure 5] 10 is a flowchart showing the process before and after the start of probing. [Figure 6] FIG. 10 is a diagram schematically illustrating an internal structure of a prober according to a modified example. [Figure 7] FIG. 10 is a diagram showing a narrow area near a mounting hole in a headstage. [Figure 8] 10 is a flowchart showing the process before and after the start of probing. 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. The inspection area of ​​the prober is equipped with equipment and mechanisms for inspecting or observing the wafer, and therefore has narrow areas due to the structure and arrangement of these devices. In this configuration, a first purge that supplies dry gas to the entire inspection area and a second purge that supplies dry gas locally to a specific narrow area are performed in parallel.

[0014] The second purge has a lower flow rate of dry gas than the first purge, but can supply dry gas precisely to narrow areas where the dew point is difficult to lower. Therefore, by promoting the lowering of the dew point in narrow areas, the dew point of the entire inspection area can be lowered quickly, thereby reducing the consumption of dry gas. In this embodiment, dry air is used as the dry gas. Details of this will be explained below.

[0015] FIG. 1 is a perspective view 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 includes a housing 2 that is generally rectangular in front view and plan view. An inspection area 10 where wafer inspection is performed is provided inside the housing 2. A loader unit that transports wafers to and from the inspection area 10 is installed on the side of the housing 2, but illustration and description of this unit are omitted.

[0016] A head stage 4 is provided to form the upper surface of the housing 2. A mounting hole 14 for mounting a probe card (described later) is provided in the center of the upper surface of the head stage 4. The head stage 4 supports the probe card and is attached to the housing 2. An alignment camera 18 is provided on the top of the housing 2 (i.e., above the inspection area 10). The alignment camera 18 takes images of the surface of the device in order to detect the electrode positions of the device on the wafer. A heat sink 19 for cooling is provided on the alignment camera 18 to prevent thermal expansion due to temperature changes and to prevent equipment failure due to heat. These will be described in detail later.

[0017] The prober 1 is also provided with a control unit 20 that controls each functional unit (mechanism and device) of the prober 1. 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 used as a work area for storing data and executing programs, an input / output interface, a user interface, etc. The control unit 20 controls each functional unit according to the control program.

[0018] Fig. 2 is a diagram schematically illustrating the internal structure of the prober 1, showing a cross section taken along the line AA in Fig. 1. The testing area 10 is separated from an external area such as a loader area by a partition wall 21.

[0019] An alignment device 22 is disposed in the inspection area 10. The alignment device 22 detachably supports a wafer chuck 24. The wafer chuck 24 has a vacuum suction structure, and attracts and fixes the wafer W by operating a suction device (e.g., a vacuum pump, not shown). A heating / cooling structure 25 is provided inside the wafer chuck 24 to heat or cool the upper surface of the wafer chuck 24 and thus the wafer W prior to the probing process. 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.

[0020] Alignment device 22 includes an X-table 26, a Y-table 28, and a Z-table 30. Guide rails 32 extending in the X-direction are provided on base 6 of housing 2. X-table 26 is installed horizontally so that it can move in the X-direction along guide rails 32. X-table 26 is driven by a movement mechanism (not shown).

[0021] A guide rail 34 extending in the Y direction is provided on the upper surface of X table 26. Y table 28 is installed horizontally so that it can move in the Y direction along guide rail 34. Y table 28 is driven by a movement mechanism (not shown). In this embodiment, 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.

[0022] The Z table 30 is supported by the Y table 28. The Z table 30 is provided with an elevation mechanism for raising and lowering the Z table 30 in the Z direction, and a rotation mechanism (not shown) for rotating the Z table 30 around the axis L (in the θ direction). The rotation mechanism is realized by, for example, a spindle motor. With this configuration, the wafer chuck 24 can move in each of the X, Y, Z, and θ directions.

[0023] A mounting hole 14 is provided in the center of the head stage 4, and a probe card 40 is detachably attached to the mounting hole 14. The mounting hole 14 has a stepped circular shape that is complementary to the probe card 40, and is closed when the probe card 40 is fitted into the mounting hole 14. The probe card 40 has probes 42. The tester 16 is assembled to the head stage 4 so that it is positioned directly above the mounting hole 14.

[0024] The tester 16 is connected to the probe card 40 via a pogo frame 44. The pogo frame 44 functions as an interface connecting the tester 16 and the probe card 40. That is, the pogo frame 44 has pogo pins (not shown) that electrically connect terminals formed on the lower surface of the tester 16 (the surface facing the pogo frame 44) to terminals formed on the upper surface of the probe card 40 (the surface facing the pogo frame 44). The tester 16 is electrically connected to the probes 42 of the probe card 40, and during testing, supplies test signals (electrical signals) to each device on the wafer W and detects output signals from each device to obtain electrical characteristics. This allows testing to determine whether each device is operating normally.

[0025] An alignment camera 18 is provided above the inspection area 10 at a position offset in the X direction from the mounting hole 14. The alignment camera 18 is configured by housing an image pickup element 52 (CCD), a lens 54, and a total reflection mirror 56 in a rectangular parallelepiped housing 50. The optical axis of the alignment camera 18 is directed downward in the housing 50 by the total reflection mirror 56 (see the two-dot chain line). When detecting the electrode positions of the device, the alignment device 22 is driven, and the wafer chuck 24 supporting the wafer W moves to a position below the housing 50. The lens 54 forms an image of the surface of the wafer W on the image pickup element 52.

[0026] A heat sink 19 is arranged along the bottom surface of the housing 50. A heat pipe 58 for cooling is provided in the heat sink 19, which can cool the alignment camera 18 when it is in a heated state. An opening 60 is provided in the heat sink 19 directly below the total reflection mirror 56, so that the optical axis of the alignment camera 18 is not blocked.

[0027] The alignment camera 18 captures an image of the surface of the wafer W and outputs the captured image to the control unit 20. The control unit 20 processes the captured image and detects the electrode positions of the devices formed on the wafer W.

[0028] 3A and 3B are diagrams showing the configuration of the alignment camera 18 and the heat sink 19. Fig. 3A is a perspective view, and Fig. 3B is a cross-sectional view taken along the line BB in Fig. 3A. As shown in FIG. 3(A), a heat sink 19 is disposed so as to abut on the entire lower surface of the alignment camera 18.

[0029] 3(B), the heat sink 19 has a flat heat sink body 62. The heat sink body 62 is configured by assembling two flat heat conduction plates 62a and 62b one above the other. The alignment camera 18 and a heat pipe unit 64 are disposed adjacent to each other on the upper surface of the heat conduction plate 62a. The heat pipe unit 64 includes a plurality of heat pipes 58.

[0030] The gap between the upper and lower heat conduction plates 62a, 62b is set narrow, forming a minute space S (narrow area) between them. A circular opening 60 is provided so as to penetrate these heat conduction plates 62a, 62b from top to bottom. A pipe 66 for purging the minute space S with dry air is further attached to the heat sink body 62. The pipe 66 is connected to a dry air supply source (described below). The tip of the pipe 66 forms a discharge portion 68 that discharges dry air, and the minute space S is purged with the dry air discharged from the discharge portion 68. With this configuration, dry air can also be introduced into the opening 60.

[0031] Returning to Fig. 2, the inspection area 10 is provided with a plurality of discharge units that discharge dry air to prevent condensation. That is, the inspection area 10 is provided with a discharge unit 67 for supplying dry air evenly throughout the entire area, and a discharge unit 68 for supplying dry air locally to the heat sink 19. The discharge unit 67 opens toward the inside of the inspection area 10. A dew point (referred to as a "set dew point") necessary to prevent condensation in the inspection area 10 is set in advance, and the control unit 20 controls the supply of dry air according to the set dew point.

[0032] The prober 1 includes a supply unit 72 for supplying dry air to the inspection area 10. The supply unit 72 includes a dry air supply source 74, a gas supply path 76, and a plurality of control valves (an on-off valve 78, and flow control valves 80 and 82). The gas supply path 76 branches into a first supply path 84 and a second supply path 86 at a branch point P1. The first supply path 84 is connected to the discharge portion 67, and the second supply path 86 is connected to the discharge portion 68.

[0033] The dry air supply source 74 has a tank that stores pressurized dry air. An on-off valve 78 is provided upstream of the branch point P1 in the gas supply path 76. A flow control valve 80 is provided in the first supply path 84, and a flow control valve 82 is provided in the second supply path 86. In this embodiment, the on-off valve 78 is a solenoid-driven electromagnetic valve, but it may also be a motor-driven electric valve. In this embodiment, the flow control valves 80 and 82 are electric valves, but they may also be solenoid valves.

[0034] In this embodiment, the dry air supply source 74, the on-off valve 78, the flow rate control valve 80, and the discharge unit 67 function as a "first supply unit" that supplies dry air to the entire inspection area 10. The dry air supply source 74, the on-off valve 78, the flow rate control valve 82, and the discharge unit 68 function as a "second supply unit" that supplies dry air locally to the minute space S of the heat sink 19, i.e., a portion of the inspection area 10. The supply of dry air from the dry air supply source 74 can be started or stopped by opening or closing the on-off valve 78. The supply of dry air by the first supply unit can be started or stopped by opening or closing the flow rate control valve 80. The flow rate of dry air supplied by the first supply unit can be adjusted by adjusting the aperture of the flow rate control valve 80. The supply of dry air by the second supply unit can be started or stopped by opening or closing the flow rate control valve 82. The flow rate of dry air supplied by the second supply unit can be adjusted by adjusting the aperture of the flow rate control valve 82. In this embodiment, the supply of dry air by the second supply unit is stopped by closing the flow control valve 82 when purging of the minute space S is completed, thereby making it possible to reduce consumption of dry air.

[0035] The control unit 20 controls the supply of dry air by the supply unit 72. Prior to the execution of the probing process, the control unit 20 opens the on-off valve 78 and controls the valve apertures of the flow control valves 80 and 82 based on the set dew point of the inspection area 10. That is, the control unit 20 controls the flow rate of dry air supplied evenly to the entire inspection area 10 by controlling the aperture of the flow control valve 80, and controls the flow rate of dry air supplied to the minute space S of the heat sink 19 by controlling the aperture of the flow control valve 82.

[0036] Specifically, regarding the temperature environment during probing, the lowest temperature that can be reached in the inspection area 10 is defined as the "required dew point." If the inspection area 10 is filled with normal air (atmospheric air), condensation is expected to occur if the temperature within the area drops below this required dew point. Therefore, a temperature that is a predetermined temperature lower than the required dew point for the inspection area 10 is set in advance as the "set dew point." To reliably prevent condensation, a margin is provided in the set dew point. This predetermined temperature (also called the "dew point margin") can be set appropriately depending on the installation environment of the prober 1, temperature change factors such as the amount and time of inflow and outflow of dry air, etc. The set dew point is set lower than the required dew point by the dew point margin.

[0037] In the inspection area 10, it is particularly necessary to prevent condensation on the devices of 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 24 with the heating and cooling structure 25. The dew point in the inspection area 10 must be -40°C or lower, but considering the possibility that the dew point may rise due to the loading and unloading of the wafer W, a dew point margin of 10°C is set, for example, and the set dew point is set to -50°C.

[0038] 4A and 4B show an example of a method for preventing dew condensation. 4A and 4B show a process for detecting the electrode positions of a device on a wafer W. Prior to this process of detecting the electrode position, the control unit 20 starts supplying dry air from the discharge unit 67 while retracting the wafer chuck 24 from directly below the opening 60 (FIG. 4(A)). Then, the control unit 20 starts supplying dry air from the discharge unit 68.

[0039] At this time, although the discharge flow rate from discharge portion 68 is smaller than the discharge flow rate from discharge portion 67, the minute space S is narrow, so dry air can be quickly distributed throughout. This allows the dew point around opening 60 to quickly approach the set dew point. In other words, the dew point in the narrow area around opening 60 can be lowered before the dew point of the entire space excluding the narrow area in inspection area 10 drops. After the dew point around opening 60 reaches the set dew point, control portion 20 stops the supply of dry air from discharge portion 68 while continuing the supply of dry air from discharge portion 67.

[0040] Thereafter, the control unit 20 moves the wafer chuck 24 to directly below the opening 60 and executes the electrode position detection process (FIG. 4(B)). In this way, by lowering the dew point around the opening 60 (specific location) prior to the electrode position detection process, it is possible to prevent condensation from occurring around the opening 60. Furthermore, by keeping the wafer chuck 24 retracted while dry air is being discharged from the discharge unit 68, it is possible to prevent moisture from scattering along with the dry air and adhering to the wafer W.

[0041] 5 is a flowchart showing the processing steps before and after the start of probing. This processing step will be explained below with reference to FIGS. Prior to the probing process, the control unit 20 moves the wafer chuck 24 to a predetermined retreat position (S10). This "retreat position" may be directly below the tester 16 as shown in FIG. 4(A), but is set in advance to a position that is out of the alignment position (i.e., directly below the opening 60).

[0042] Next, the control unit 20 opens the on-off valve 78 and the flow control valve 80 to start supplying dry air from the discharge unit 67 (also referred to as a "first purge" or "total purge") (S12). At this time, the flow rate of dry air discharged from the discharge unit 67 is adjusted by adjusting the opening of the flow control valve 80. This flow rate is set in advance to a necessary and sufficient flow rate (first flow rate) based on the set dew point of the inspection area 10 and the set time (preset as a first required time) required for the temperature of the entire inspection area 10 to drop to that set dew point.

[0043] The control unit 20 also opens the flow control valve 82 to start supplying dry air from the discharge unit 68 (also referred to as a "second purge" or a "local purge") (S14). At this time, the flow rate of the dry air discharged from the discharge unit 68 is adjusted by adjusting the opening of the flow control valve 82. This flow rate is set in advance to a necessary and sufficient flow rate (second flow rate) based on the set dew point of the inspection area 10 and the set time (preset as the second required time) required to lower the microspace S of the heat sink 19 to the set dew point. Because the microspace S is narrow, the second flow rate is lower than the first flow rate, and the second required time is shorter than the first required time.

[0044] Then, when the set time (second required time) for the second purge has elapsed (Y in S16), the control unit 20 closes the flow control valve 82 to stop the second purge (S18).

[0045] Thereafter, the control unit 20 drives the alignment device 22 to move the wafer chuck 24 to the alignment position, i.e., directly below the alignment camera 18 (S20). As a result, the surface of the wafer W is positioned on the optical axis of the alignment camera 18 (see the two-dot chain line). The control unit 20 then executes an alignment process to detect the electrode positions of the device (S22). This alignment process is well known, so a description thereof will be omitted.

[0046] When the alignment process is completed (Y in S24), the control unit 20 drives the alignment device 22 to move the wafer chuck 24 to a predetermined inspection position (S26). When probing is performed in a low-temperature environment, the control unit 20 starts cooling the wafer chuck 24 on the condition that the inspection area 10 has reached the set dew point by the first purge (S28). Then, the probing process starts (S30).

[0047] As described above, in this embodiment, a general purge, which supplies dry air to the entire inspection area 10, and a local purge, which supplies dry air locally to the microspace S of the heat sink 19, are performed in parallel. The microspace S is a small area where the dew point is difficult to lower with a general purge. Therefore, the local purge is performed separately from the general purge, allowing for a concentrated dew point lowering. Furthermore, since the local purge only needs to function in the small area, a small purge flow rate is required. Because the general purge and the local purge are performed simultaneously and during part of the general purge period, there is no need to extend the general purge time to adjust the dew point of the microspace S. In other words, this embodiment allows for a rapid reduction in the dew point of the entire inspection area 10 while reducing dry air consumption. As a result, the overall throughput of semiconductor manufacturing can be increased.

[0048] 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.

[0049] [Variations] Fig. 6 is a diagram schematically illustrating the internal structure of a prober according to a modified example, and corresponds to Fig. 2. However, the alignment camera 18 and its peripheral configuration described in the above embodiment are not shown and will not be described.

[0050] In this modification, a second purge (local purge) is performed on the corners of the inspection area 10 (for example, the four upper and lower corners) and on the narrow areas near the mounting holes 14. The corners are also areas where air stagnates in the inspection area 10, so moist air tends to accumulate. Therefore, local purge is performed on these areas. That is, the inspection area 10 is provided with a plurality of discharge units 110 capable of discharging dry air toward these corners, and a plurality of discharge units 112 capable of discharging dry air toward the areas near the mounting holes 14.

[0051] 7A and 7B are diagrams showing a narrow area near the mounting hole 14 in the head stage 4. FIG. 7A is a perspective view showing the mounting hole 14 and its vicinity (see FIG. 1). FIG. 7B is a cross section taken along the arrow CC in FIG. 7A. However, the probe card 40, the tester 16, etc. (see FIG. 2) are not shown.

[0052] An automatic card exchange mechanism 120 is provided near the mounting hole 14 in the head stage 4 to automatically exchange the probe card 40 with an external device (not shown). The automatic card exchange mechanism 120 has multiple annular members arranged concentrically, and a narrow area S1 where moist air tends to accumulate is present between them. In this modification, dry air is supplied from the discharge portion 112 toward the narrow area S1 (i.e., a second purge is performed), thereby quickly bringing the dew point around the narrow area S1 closer to the set dew point.

[0053] 6, prior to the probing process, the control unit 20 supplies dry air from the discharge units 110 and 112 in parallel with the supply of dry air from the discharge unit 67 (second purge). The supply of dry air from the discharge units 110 and 112 is stopped before the probing process starts. During this second purge, the wafer chuck 24 is retracted from directly below the narrow area S1.

[0054] FIG. 8 is a flowchart showing the processing steps before and after the start of probing. Prior to the probing process, the control unit 20 moves the wafer chuck 24 to a predetermined retreat position (S10). This "retreat position" is set in advance to a position that is not directly below the narrow area S1.

[0055] Next, the control unit 20 opens the on-off valve 78 and the flow control valve 80 to start the supply of dry air from the discharge unit 67 (first purge) (S12). Then, when a predetermined first set time has elapsed (Y in S13), the control unit 20 opens the flow control valve 82 to start the supply of dry air from the discharge units 110, 112 (second purge) (S14). That is, while in the above embodiment the overall purge and the local purge were started almost simultaneously, in this modified example the local purge is started slightly later than the overall purge. Then, when the set time for the second purge (second set time) has elapsed (Y in S16), the control unit 20 closes the flow control valve 82 to stop the second purge (S18).

[0056] Thereafter, the control unit 20 drives the alignment device 22 to move the wafer chuck 24 to the inspection position (S26). When probing is performed in a low-temperature environment, the control unit 20 starts cooling the wafer chuck 24 on the condition that the inspection area 10 has reached the set dew point (S28). Then, the probing process starts (S30).

[0057] In this modified example, the overall purge (first purge) of the inspection area 10 and the local purge (second purge) of the small area S1 are performed simultaneously, with the local purge being performed during part of the overall purge period. This allows the dew point of the entire inspection area 10 to be quickly lowered. Because the overall purge is performed for a predetermined time (first set time) prior to the second purge, the dew point in the vicinity of the small area S1 can be lowered to a considerable extent. This allows the execution time of the second purge to be set shorter accordingly.

[0058] [Other variations] In the above embodiment, an example was shown in which dry air was used as the dry gas, but a dry inert gas or other dry gases may also be used.

[0059] In the above embodiment, the wafer W is exemplified as a component that is affected by condensation, and the alignment camera 18 and the heat sink 19 are exemplified as specific components or members that may be located above the wafer W. In a modified example, the probe card 40 may be the component that is affected by condensation and be subject to condensation prevention. As in the modified example shown in FIG. 7(B), by performing a local purge (second purge) of the narrow area S1, condensation can be prevented not only on the wafer W but also on the probe card 40 located diagonally below the wafer W.

[0060] In the above embodiment, the heat sink 19 including the heat pipe 58 is exemplified as the heat countermeasure component that is integral with the alignment camera 18. In a modified example, a heat sink that does not include a heat pipe may be used as the heat countermeasure component. In this case, fins or the like may be provided on the heat sink. Alternatively, a heat shield plate with a heat dissipation function may be used as the heat countermeasure component.

[0061] In the above embodiment, a single-stage prober in which a single tester 16 is provided for the inspection area 10 has been exemplified, but a multi-stage prober in which multiple testers are provided for the inspection area may also be employed. In this case, too, a full purge in which dry gas is supplied to the entire inspection area and a local purge in which dry gas is supplied locally to a specific narrow area are performed in parallel.

[0062] In the above embodiment, probing in a low temperature environment has been mainly described, but it goes without saying that inspections can also be performed at a plurality of temperatures ranging from low to high temperatures.

[0063] In the above embodiment, only the wafer position alignment process for detecting the electrode positions of the device on the wafer W was mentioned as a process performed prior to probing, but in reality, a probe position alignment process for detecting the positions of the probes of the probe card is also performed. Through these alignment processes, the positional relationship between the multiple probes and the device electrodes is detected, and adjustments are made to ensure accurate contact between them.

[0064] That is, after detecting the positions of the probes and the device electrodes, the wafer chuck is rotated so that the arrangement direction of the device electrodes matches that of the probes. During probing, the wafer chuck is moved so that the electrodes of the device to be tested are positioned directly under the probes, and then the wafer chuck is raised to bring the device electrodes into contact with the probes. A voltage is then applied to the device from the tester to measure its electrical characteristics.

[0065] Although not mentioned in the above embodiment, an on-off valve (a solenoid valve dedicated to the second supply unit) may be provided in addition to the flow rate control valve 82 in the second supply path 86 shown in Fig. 2. When the flow rate of the dry gas supplied by the second supply unit is small and flow rate adjustment itself is not necessary, an on-off valve (solenoid valve) may be provided instead of the flow rate control valve 82.

[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 head stage, 6 base, 10 inspection area, 14 mounting hole, 16 tester, 18 alignment camera, 19 heat sink, 20 control unit, 22 alignment device, 24 wafer chuck, 25 heating and cooling structure, 40 probe card, 42 probe, 44 pogo frame, 58 heat pipe, 60 opening, 62 heat sink body, 64 heat pipe unit, 66 piping, 67 discharge part, 68 discharge part, 72 supply part, 74 dry air supply source, 76 gas supply path, 78 on-off valve, 80 flow control valve, 82 flow control valve, 84 first supply path, 86 second supply path, 110 discharge part, 112 discharge part, 120 automatic card exchange mechanism, S microspace, W wafer.

Claims

1. A prober for inspecting electrical characteristics of devices formed on a wafer, comprising: a housing in which an inspection area where inspection is performed is formed; a first supply unit that supplies dry gas to the entire inspection area; a second supply unit that supplies dry gas locally to a portion of the inspection area; a control unit that controls the supply of dry gas by each supply unit; The prober includes:

2. 2. The prober according to claim 1, wherein the control unit controls the second supply unit to supply the dry gas during a part of a period in which the first supply unit supplies the dry gas.

3. 3. The prober according to claim 1, wherein the second supply unit supplies dry gas locally to a specific component or member that may be located above a component that is affected by condensation.

4. a wafer chuck for holding the wafer; an alignment camera that captures an image of a surface of the device formed on the wafer to detect the position of an electrode of the device; a heat countermeasure component provided integrally with the alignment camera; a moving mechanism that moves the wafer chuck below the alignment camera when the alignment camera takes an image; Equipped with The prober according to claim 3 , wherein the second supply unit supplies the dry gas toward a specific location on the thermal protection component that may be located directly above the wafer.

5. 5. The prober according to claim 4, wherein the control unit controls the second supply unit to supply the dry gas when the wafer chuck is retracted from directly below the specific location.

6. 3. The prober according to claim 1, wherein the second supply unit supplies the dry gas toward a corner or a narrow area of ​​the inspection area.

7. 3. The prober according to claim 1, wherein the second supply unit supplies the dry gas toward a stagnant portion of air in the inspection area.

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