JP5061751B2 - Wafer holder for wafer prober - Google Patents

Description

  The present invention relates to a wafer holder used in a wafer prober for inspecting electrical characteristics of a semiconductor wafer placed on a wafer placement surface, and a wafer prober on which the wafer holder is placed.

  Conventionally, in a semiconductor inspection process, a heat treatment is performed on a semiconductor substrate (wafer) that is an object to be processed. In other words, the wafer is heated to a temperature higher than the normal use temperature, and semiconductor chips that may become defective are accelerated and removed, and burn-in is performed to prevent the occurrence of defects after shipment. .

  In this burn-in process, the electrical performance of each chip is measured while heating the wafer, and defective products are removed. Specifically, after forming a semiconductor circuit on a semiconductor wafer and before cutting into individual chips, the semiconductor wafer is placed on the wafer placement surface of the chuck top, and the probe card is pushed onto the wafer while the wafer is heated. Inspect the electrical characteristics of the wafer. A heater provided on the chuck top is used for heating the wafer.

  The chuck top used in such a burn-in process is made of metal because the entire back surface of the wafer needs to be in contact with the ground electrode. A wafer is placed on the flat metal chuck top and the electrical characteristics are measured. At the time of measurement, a probe called a probe card having a large number of electrode pins for energization has several tens kgf to several hundred kgf on the wafer. It is pressed with the power of For this reason, if the metal chuck top is thin, it may be deformed, resulting in poor contact between the wafer and the probe pins.

  In order to eliminate contact failure due to deformation of the chuck top described above, a thick metal plate having a thickness of 15 mm or more has been conventionally used as the chuck top for the purpose of maintaining rigidity. For this reason, in this burn-in process, although a reduction in process time is strongly demanded to improve the throughput, it takes a long time to raise and lower the temperature of the heater, which has been a major obstacle to improving the throughput.

  In order to solve this problem, Japanese Patent Laid-Open Nos. 2001-033484 and 2006-253630 describe the use of a highly rigid ceramic material as a chuck top. In particular, Japanese Patent Application Laid-Open No. 2006-253630 discloses a heat insulating structure in which a support member is disposed in a gap between a chuck top and a support in order to improve throughput.

JP 2001-033484 A JP 2006-253630 A

  In recent years, there has been a demand for higher temperature uniformity in a wafer, and a temperature range of ± 0.5 ° C. or less is required in a 300 mm wafer. However, according to the method described in the above patent document, it is possible to improve the throughput by securing the high rigidity of the chuck top, but it is difficult to satisfy the above-mentioned requirement of high temperature uniformity, especially in the chuck top. In an electrostatic chuck that requires high insulation, the temperature range is only about ± 3 ° C. because thermal conductivity is sacrificed.

  In view of such a conventional situation, the present invention is excellent in a heat insulating structure without impairing the high rigidity of the chuck top, excellent in the uniformity of the temperature distribution of the wafer in a wide temperature range, and reduced in weight. An object of the present invention is to provide a wafer holder for a wafer prober that can be used, and a wafer prober provided with the wafer holder.

  In order to achieve the above-mentioned object, the present inventors have used a high thermal conductivity material as a soaking plate for heat diffusion as a soaking plate for heat diffusion without impairing the high rigidity of the chuck top. An attempt was made to attach to the side opposite to the wafer mounting surface. As a result, by appropriately setting the size and mounting structure of the soaking plate, the temperature range of the chuck top is improved from ± 1 ° C to ± 0.5 ° C, and ± 3 ° C for electrostatic chucks. The present inventors have found that the temperature range is ± 1.5 ° C. and have come to make the present invention.

  That is, a wafer holder for a wafer prober provided by the present invention includes a chuck top having a chuck top conductor layer on the surface, and a soaking plate made of a high thermal conductivity material provided on the back side opposite to the wafer mounting surface of the chuck top. And a cushioning material disposed between the chuck top and the heat equalizing plate and having a lower rigidity than both parts, a bottomed cylindrical support for supporting the chuck top, and a back surface of the heat equalizing plate so as not to contact the support The soaking plate has an outer diameter of 95% or more with respect to the outer diameter of the chuck top in a temperature range of −55 ° C. to 200 ° C.

In the wafer holder for a wafer prober according to the present invention, the support is provided with a notch slot M1 leaving a plurality of protrusions that are in contact with and supported by the outer periphery of the back surface of the chuck top. The plate and the cushion material are provided with a plurality of notch slots M2 so as not to come into contact with the protrusions of the support, and the heat equalizing plate, the cushion material and the heating body are provided with the notch slots of the support. M1 is installed so as to fill the total area of the cutout slot M1 of the support, Ru der least 50% of the total area of the notch slot M2 of the soaking plate.

  In the wafer holder for a wafer prober of the present invention, a cooling unit capable of cooling control can be provided on the back surface side of the soaking plate. The soaking plate and the cooling unit may be integrated.

  The present invention also provides a wafer prober comprising the wafer holder for a wafer prober according to the present invention described above.

  According to the present invention, it is highly rigid and has no fear of warping or deformation, has an excellent heat insulation structure, has a high thermal conductivity on the wafer mounting surface, and has an excellent uniformity of wafer temperature distribution in a wide temperature range. A wafer holder for a wafer prober can be provided. Further, by mounting a cooling unit, the temperature increase / decrease rate of the chuck top can be improved.

  Therefore, by mounting the wafer holder for the wafer prober of the present invention, contact failure between the wafer and the probe pins due to warpage or deformation is prevented, and the positional accuracy is excellent and the heat uniformity over the entire wafer surface is excellent. In addition, it is possible to obtain a wafer prober that can raise and lower the temperature in a short time.

  The wafer holder for a wafer prober of the present invention will be specifically described with reference to FIG. The wafer holder 1 includes a chuck top 2 having a chuck top conductor layer 3, a soaking plate 7 and a cushion material 8 having the same diameter as the chuck top 2, and a bottomed cylindrical support 4 that supports the chuck top 2. A gap 5 as an air layer exists between the chuck top 2 and the support 4. Since the support 4 has a bottomed cylindrical shape, the contact area between the chuck top 2 and the support 4 can be reduced, and at the same time, the gap 5 can be easily formed.

  In the gap 5 between the chuck top 2 and the support 4, the heating body 6 attached to the soaking plate 7 is accommodated so as not to contact the support 4. When the wafer mounted on the mounting surface 2a of the chuck top 2 is inspected, the chuck top 2 is heated by the heating body 6, and the gap 5 serves to enhance the heat insulation effect during this heating or cooling. There is no restriction | limiting in particular in the shape of the space | gap 5, It is preferable to set it as the shape which suppresses the quantity which the heat | fever and cold which generate | occur | produced with the heating body 6 are transmitted to the support body 4 as much as possible. The heating body 6 can be fixed to the soaking plate 7 by a mechanical method such as screwing. The heating element 6 includes a resistance heating element and can be temperature controlled.

  The soaking plate 7 is attached to the back surface (surface opposite to the wafer mounting surface 2a) of the chuck top 2 in order to promote thermal diffusion during heating and cooling. As the material of the soaking plate 7, it is preferable to use a material having high thermal conductivity, for example, a metal material such as copper, aluminum, graphite, and carbon nanofiber, a ceramic material such as boron nitride and aluminum nitride, or These composite materials can be used.

  The soaking plate 7 needs to have an outer diameter of 95% or more with respect to the outer diameter of the chuck top 2 in a temperature range of −55 ° C. to 200 ° C. Since the soaking plate 7 has the above-mentioned outer diameter ratio with respect to the chuck top 2, the uniformity of the chuck top temperature (soaking property) can be greatly improved in the normal operating temperature range of the wafer prober.

  In order to improve the thermal contact, a cushion material 8 having rigidity lower than that of both components is inserted between the soaking plate 7 and the chuck top 2. The cushion material 8 absorbs mutual elongation and warpage due to thermal expansion and lowers the thermal resistance between the heat equalizing plate 7 and the chuck top 2. The material of the cushion material 8 is preferably a material with high thermal conductivity and low rigidity. For example, graphite, boron nitride, silicon resin in which a high thermal conductivity material is dispersed, or the like can be used.

  The soaking plate 7 and the cushion material 8 are fixed to the back surface of the chuck top 2 by a mechanical method such as screwing. At that time, it is preferable that the soaking plate 7 and the cushion material 8 do not come into contact with the support body 4 in the same manner as the heating body 6. If the soaking plate 7 or the cushion material 8 is in contact with the support 4, the soaking in the vicinity of the contact portion is disturbed, and the heat escapes to the support 4, so that the soaking property of the chuck top 2 is lowered. Because.

  Therefore, as shown in FIG. 2, the bottomed cylindrical support 4 is formed with a notch slot M1 (a portion indicated by hatching in the drawing) leaving a plurality of protrusions 4a on the outer peripheral portion. The notch slot M1 includes a cylindrical inner portion of the bottomed cylindrical support 4 (inside the dotted line shown in the figure). Further, since the plurality of protrusions 4a remaining on the support body 4 abuts and supports the outer peripheral portion of the back surface of the chuck top 2 by providing the notch slot M1, the heat insulating structure with a small area of the contact portion and can do. In addition, the cross-sectional shape of the protrusion part 4a is not restricted circular, and may be arbitrary shapes.

  On the other hand, the soaking plate 7 and the cushion material 8 are provided with a plurality of notch slots M2 (indicated by diagonal lines in the drawing) so as not to contact the support 4 as shown in FIGS. The part shown by) is provided. The cross-sectional shape of the cutout slot M2 may be a circle as shown in FIG. 3, an ellipse or a trapezoid as shown in FIG. 4, a polygon such as a triangle or a rectangle, and other shapes. A combination of these may be used. In addition, when the heating body 6 is the same size as the soaking plate 7 and the cushioning material 8, the heating body 6 is also attached to the heating body 6 in the same manner as the soaking plate 7 and the cushioning material 8 so as not to contact the support 4. A notch slot M2 can be provided.

  Then, the soaking plate 7 and the cushion material 8 are installed so as to fill the notch slot M1 of the support 4. At that time, for example, as shown in FIG. 5 and FIG. 6 illustrated for the heat equalizing plate 7, the plurality of protruding portions 4 a of the support body 4 provided with the notched groove hole M 1 are replaced with the notched grooves of the heat equalizing plate 7 and the cushion material 8. By passing through the hole M2, the heat equalizing plate 7 and the cushion material 8 can be arranged so as not to contact the support 4.

  The notch so that the total area of the notch slot M1 provided in the support 4 is 50% or more of the total area of the notch slot M2 provided in the heat equalizing body 7 (may be provided in the cushion material 8). It is preferable to form the slot M1 and the notch slot M2. Thereby, the escape of heat from the heat equalizing plate 7 or the cushion material 8 to the support 4 is suppressed, and the heat equalizing plate 7 compensates the disturbance of the heat equalization, thereby further improving the heat uniformity of the chuck top 2. it can.

  Further, as shown in FIG. 7, a support bar 9 that supports the chuck top 2 can be provided near the center of the support 4. In this case, it is preferable that the soaking plate 7 and the cushion material 8 do not contact the support rod 9. Therefore, for example, as shown in FIG. 8 illustrating the heat equalizing plate, a through hole is formed in the center portion of the heat equalizing plate 7 and the cushion material 8, and the support bar 9 is inserted into the through hole to support the chuck top 2. It is preferable to do.

  As the heating element 6, as shown in FIG. 9, it is preferable to sandwich a resistance heating element 6a between insulators 6b because the structure is simple. A metal material can be used for the resistance heating element 6a. For example, nickel, stainless steel, silver, tungsten, molybdenum, chromium, and alloys of these metals can be used. Of these metals, stainless steel and nichrome are preferred. With stainless steel or nichrome, the resistance heating element circuit pattern can be easily and relatively accurately formed by a technique such as etching. Moreover, since it is inexpensive and has oxidation resistance, there is an advantage that it can withstand long-time use at high temperatures.

  The insulator 6b sandwiching the resistance heating element 6a is not particularly limited as long as it has heat resistance, and for example, mica, silicon resin, epoxy resin, phenol resin, or the like can be used. When the resistance heating element is sandwiched between insulating resins, a filler can be dispersed in the resin in order to transfer heat to the chuck top more smoothly. The filler material is not particularly limited as long as there is no reactivity with the resin, and examples thereof include boron nitride, aluminum nitride, alumina, and silica.

  As shown in FIG. 10, the wafer holder for a wafer prober of the present invention can include a cooling unit 10 in the cylindrical portion of the support 4. The cooling unit 10 rapidly cools the chuck top 2 by removing the heat when the chuck top 2 needs to be cooled. When heating the chuck top 2, the cooling unit 10 is preferably movable because the cooling unit 10 can be separated from the chuck top 2 to increase the temperature efficiently.

  In the case of the movable cooling unit 10, the cooling unit 10 is moved in the vertical direction using the lifting / lowering means 11 such as an air cylinder. Such a movable type is preferable because the cooling rate of the chuck top can be greatly improved and the throughput can be increased. In the case of a movable cooling unit, the cooling capacity is higher than that of air cooling, and the cooling unit is not subjected to any pressure by the probe card at the time of probing. Therefore, the cooling unit is not deformed by pressure.

  Further, when priority is given to the cooling rate of the chuck top, the cooling unit may be fixed to the soaking plate. As a fixing form, as shown in FIG. 11, a cooling unit 10 is installed on the lower surface of the soaking plate 7, and a heating body 6 having a structure in which a resistance heating element is sandwiched between insulators is installed and fixed on the lower surface. be able to. As another fixing form, as shown in FIG. 12, a soaking cooling unit 12 in which a soaking plate and a cooling unit are integrally formed is used, and a resistance heating element is provided on the lower surface of the soaking cooling unit 12 as an insulator. There is a method of fixing the heating element 6 having a structure sandwiched between the two.

  In any of the above-described fixing forms, the fixing method is not particularly limited, but can be fixed by a mechanical technique such as screwing or clamping. Also, when fixing the chuck top, cooling unit, and heating element with screws, the number of screws is 3 or more, and further 6 or more improves the adhesion between them, further improving the cooling capacity of the chuck top. Therefore, it is preferable.

  The material of the cooling unit is not particularly limited, but aluminum, copper, and alloys thereof are preferable because they have a relatively high thermal conductivity and can quickly take away the heat of the chuck top. Stainless steel, magnesium alloy, nickel, and other metal materials can also be used. In order to impart oxidation resistance to the cooling unit, a metal film having oxidation resistance such as nickel, gold, and silver can be formed on the surface using a technique such as plating or thermal spraying.

  Ceramics can also be used as the material for the cooling unit. There are no particular restrictions on the type of ceramic, but aluminum nitride and silicon carbide are preferred because they have a relatively high thermal conductivity and can quickly remove heat from the chuck top. Silicon nitride and aluminum oxynitride are preferable because they have high mechanical strength and excellent durability. Furthermore, oxide ceramics such as alumina, cordierite, and steatite are preferable because they are relatively inexpensive.

  As described above, since the material of the cooling unit can be variously selected, the material may be selected depending on the application. Among these materials, aluminum plated with nickel and copper plated with nickel have excellent oxidation resistance, high thermal conductivity, and are relatively inexpensive. Particularly preferred.

  The cooling unit can also flow a refrigerant therein, but in the case of a fixed type, it is also possible to raise the temperature without flowing the refrigerant. In this case, since the refrigerant does not flow into the cooling unit, the heat generated by the resistance heating element is not taken away by the refrigerant and escapes out of the system, and a more efficient temperature rise is possible. However, even in the case of the fixed type, the chuck top can be efficiently cooled by flowing the coolant through the cooling unit during cooling.

  In addition, the cooling unit can be provided with a flow path inside to allow the coolant to flow. By flowing the refrigerant in this way, the heat transmitted from the heating body to the cooling unit can be quickly removed, and the cooling rate of the heating body can be further improved, which is particularly preferable in terms of throughput improvement. Water, Fluorinert, or the like can be selected as the refrigerant flowing in the cooling unit, and water is most preferable in consideration of the specific heat and the price.

  As a suitable example of the flow path provided inside the cooling unit, two aluminum plates are prepared, and a groove corresponding to the flow path is formed in one of the aluminum plates by machining or the like. Then, in order to improve corrosion resistance and oxidation resistance, nickel plating is applied to the entire surface. The remaining one aluminum plate is also nickel-plated and bonded to the aluminum plate in which the groove is formed. At this time, for example, an O-ring is inserted so that water does not leak around the flow path, and the two aluminum plates are integrated by screwing or welding.

  Alternatively, as another example, two copper (oxygen-free copper) plates are prepared, and a groove corresponding to the flow path is formed on one of the copper plates by machining or the like. The other copper plate and a stainless steel pipe serving as the inlet / outlet of the flow path are simultaneously brazed and joined to this copper plate. Nickel plating is applied to the entire surface of the joined copper plate in order to improve corrosion resistance and oxidation resistance.

  Furthermore, as another form, it can be set as a cooling unit by attaching the pipe for flowing a refrigerant | coolant to cooling plates, such as an aluminum plate or a copper plate. In this case, it is possible to further increase the cooling efficiency by forming a counterbored groove having a shape close to the cross-sectional shape of the pipe on the cooling plate and bringing the pipe into close contact. Moreover, in order to improve the adhesiveness of a pipe and a cooling plate, you may insert thermally conductive resin, ceramics, etc. as an intervening layer between both.

  The wafer holder for a wafer prober of the present invention can be suitably used for heating and inspecting an object to be processed such as a wafer. For example, if it is mounted on a wafer prober or applied to a handler device or a tester device, it can be utilized for characteristics of high rigidity and high thermal conductivity.

[Example 1]
A wafer holder for a wafer prober according to the present invention was produced as follows. That is, an alumina substrate having a purity of 99.5%, a diameter of 310 mm, and a thickness of 15 mm was prepared. Concentric grooves and through holes for vacuum chucking the wafer were formed on the wafer mounting surface side of the alumina substrate, and further nickel plating was performed to form a chuck top conductor layer. Thereafter, the chuck top conductor layer was polished to have a total warpage of 10 μm, and the surface roughness was finished to 0.02 μm with Ra to form a wafer mounting surface, thereby forming a chuck top.

Next, a cylindrical mullite-alumina composite having a diameter of 310 mm and a thickness of 40 mm was prepared as a support. This mullite-alumina composite was subjected to counterbore processing with an inner diameter of 295 mm and a depth of 20 mm to obtain a bottomed cylindrical support. Further, the outer peripheral portion of the bottomed cylindrical support is cut by a depth of 5 mm so that the protrusions having a diameter of 5 mm remain at regular intervals, and 32 protrusions are provided to support and support the chuck top. It was. In this case, the total area of the cutout slots M1 of the support is about 75000 mm ² .

In addition, an insulating silicon resin sheet having a diameter of 310 mm and a thickness of 0.5 mm was prepared as a cushioning material. Furthermore, an oxygen-free copper disc having a diameter of 310 mm and a thickness of 2 mm was prepared as a soaking plate. The cushion material and the heat equalizing plate were each provided with 32 circular notch holes M2 each having a diameter of 8 mm so as not to contact the 32 protrusions formed on the outer periphery of the support. In this case, the total area of the notch slot M2 of soaking plate (or cushion member) is about 1600 mm ^2, thus notches total area ratio M1 / M2 of the slot is 4600%.

  A cushioning material of an insulating silicon resin sheet is stretched on the surface (rear surface) opposite to the wafer mounting surface of the chuck top, an oxygen-free copper soaking plate is stacked on the lower surface, and a heating element is attached. These were fixed and integrated with three or more screws. The heating element is obtained by sandwiching a resistance heating element obtained by etching a stainless foil into a predetermined pattern with an insulating silicon resin sheet.

  Thus, the chuck top which attached the cushioning material, the heat equalizing plate, and the heating body was mounted on the 32 protrusions of the support body to obtain the wafer holder of Example 1 according to the present invention. Moreover, as a conventional wafer prober wafer holder, a wafer holder having the same structure as the wafer holder of the present invention described above was prepared except that there was no soaking plate and cushion material, and this was used as the wafer holder of Comparative Example 1. .

  The two types of wafer holders for wafer probers were evaluated for thermal uniformity. That is, when the wafer was heated to 200 ° C. by energizing the heating body and the temperature range in the wafer was measured, the wafer holder of Example 1 was ± 1.5 ° C., and the wafer holder of Comparative Example 1 was The temperature was ± 3.0 ° C. From this result, in the wafer holder of the present invention, due to the presence of the soaking plate, the heat escape from the contact portion between the support and the chuck top and the heat escape from the outer periphery of the chuck top are greatly relieved. It can be seen that the temperature gradient in the outer peripheral direction becomes relatively gentle, and high temperature equalization is realized as compared with the conventional wafer holder.

[Example 2]
A wafer holder for a wafer prober of Example 2 and Comparative Example 2 was fabricated in the same manner as in Example 1 and Comparative Example 1 except that the material of the chuck top was Al-SiC. When the thermal uniformity was evaluated in the same manner as in Example 1, the temperature range within the wafer was ± 0.5 ° C. for the wafer holder of Example 2 and ± 1.0 ° C. for the wafer holder of Comparative Example 2. It was.

[Example 3]
In order to evaluate the influence of the outer diameter of the soaking plate on the temperature range, a wafer prober wafer in which a cooling unit made of a copper plate having a diameter of 280 mm and a thickness of 10 mm is mounted on the wafer prober wafer holder of Example 1 above. A holding body was prepared. The cooling unit was disposed on the lower surface of the soaking plate, and was fixed with a plurality of screws to be integrated with the chuck top.

  For the wafer holders of Samples 1 to 4 in which the material of the soaking plate of the wafer holder is copper and the material of the chuck top is alumina and the outer diameters of the soaking plate and the chuck top are changed, the chuck top temperature is The ratio of the outer diameter of the soaking plate to the outer diameter of the chuck top at −55 ° C., 20 ° C., and 200 ° C. was examined (the ratio of the soaking plate / chuck top outer diameter ratio), and the temperature at −55 ° C. was evaluated as the soaking property The range and the temperature range at 200 ° C. were determined, and the results obtained are shown in Table 1 below.

  For the wafer holders of Samples 5 to 8 in which the material of the soaking plate of the wafer holder is copper and the material of the chuck top is Al-SiC, and the outer diameters of the soaking plate and chuck top are changed. In the same manner as above, the soaking plate / chuck top outer diameter ratio and the soaking property of each wafer holder were examined, and the obtained results are shown in Table 2 below.

  As shown in Tables 1 and 2, when the ratio of the outer diameter of the heat equalizing plate to the outer diameter of the chuck top is less than 90%, the temperature range is almost the same as that of each wafer holder without the conventional heat equalizing plate. (See Examples 1-2 above). On the other hand, by setting the ratio of the outer diameter of the heat equalizing plate to the outer diameter of the chuck top to be 95% or more, the temperature range was significantly narrowed, and an improvement in heat uniformity was recognized in a wide temperature range.

[Example 4]
The soaking plate / chuck top outer diameter ratio and each wafer holding body were the same as in Example 3 except that the heat soaking plate was made of aluminum and the chuck top was made of alumina or Al-SiC. The soaking property was investigated. The results obtained are shown in Table 3 below when the chuck top is an alumina sample 9 to 12, and Table 4 below when the chuck top is an Al-SiC sample 13-16.

  As shown in Table 3 and Table 4, even when the material of the soaking plate is aluminum, the temperature range is greatly increased by setting the ratio of the outer diameter of the soaking plate to the outer diameter of the chuck top to 95% or more. It was narrowed and an improvement in soaking was observed in a wide temperature range.

  However, it can be seen that the narrowing of the temperature range is small compared to the results of Example 3 above. This is because the thermal conductivity of copper is 380 W / mmK, the thermal conductivity of aluminum is 240 W / mmK, the thermal conductivity of alumina is 30 W / mmK, and the thermal conductivity of Al-SiC is 200 W / mmK. This is because the difference in thermal conductivity between alumina and Al—SiC relative to aluminum in Example 4 is smaller than the difference between the thermal conductivity between alumina and Al—SiC relative to copper in Example 3 above.

[Example 5]
In the wafer holder for the wafer prober of Example 1, in place of the oxygen-free copper soaking plate having a diameter of 310 mm and a thickness of 2 mm, an oxygen-free copper soaking plate having a diameter of 310 mm and a thickness of 2 mm, a diameter of 280 mm, and a thickness of 10 mm A wafer holding body of Sample 17 was fabricated by mounting a soaking cooling unit integrated with the copper plate cooling unit. The wafer holder of Sample 17 was examined for thermal uniformity in the same manner as in Example 1, and the obtained results are shown in Table 5 below.

  For comparison, a cooling unit made of a copper plate having a diameter of 280 mm and a thickness of 10 mm is mounted on the wafer holder for the wafer prober of Example 1 above, and the ratio of the outer diameter of the soaking plate to the outer diameter of the chuck top is The soaking data for the 100% wafer holder (Sample 3 of Example 3 above) is also shown in Table 5 below.

  As can be seen from Table 5, the wafer holding body of the sample 17 has improved thermal uniformity than the wafer holder of the sample 3. This is because the sample 3 wafer holder has a thermal resistance between the soaking plate and the cooling unit, whereas the sample 17 wafer holder in which the soaking plate and the cooling unit are integrated has a heat resistance between them. It means that the thermal diffusion effect is increased because there is no resistance.

[Example 6]
In the wafer holder for the wafer prober of Example 1 above, the ratio of the total area of the cutout slot M1 of the support to the total area of the cutout slot M2 of the heat equalizing plate, that is, M1 / M2, is shown in Table 6 below. As shown, seven types of wafer holders were produced that varied between 4600% and 40%.

  Each of the obtained wafer holders was examined for thermal uniformity in the same manner as in Example 1, and the obtained results are shown in Table 6 below. As shown in Table 6, it was found that if the ratio of the total area of the cutout slot M1 and the total area of the cutout slot M2 is 50% or more, excellent temperature uniformity can be obtained in a wide temperature range. .

It is a schematic sectional drawing which shows one specific example of the wafer holder in this invention. It is a front view which shows an example of the notch slot of the support body in the wafer holder of this invention. It is a front view which shows an example of the notch slot of the soaking | uniform-heating board in the wafer holder of this invention. It is a front view which shows the other example of the notch slot of the heat equalizing plate in the wafer holder of this invention. It is a front view which shows an example of arrangement | positioning of the support body and soaking plate in the wafer holder of this invention. It is a front view which shows another example of arrangement | positioning of the support body and soaking plate in the wafer holder of this invention. It is a schematic sectional drawing which shows the other specific example of the wafer holder in this invention. It is a front view which shows an example of arrangement | positioning of the support body, heat equalizing plate, and support bar in the wafer holder of FIG. It is a schematic sectional drawing which shows one specific example of the heating body in the wafer holder of this invention. It is a schematic sectional drawing which shows one specific example of the wafer holder provided with the cooling unit in this invention. It is a schematic sectional drawing which shows the other specific example of the wafer holder provided with the cooling unit in this invention. It is a schematic sectional drawing which shows the other specific example of the wafer holder provided with the cooling unit in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer holding body 2 Chuck top 2a Mounting surface 3 Chuck top conductor layer 4 Support body 4a Protruding part 5 Space | gap 6 Heating body 6a Resistance heating element 6b Insulator 7 Heat equalizing plate 8 Cushion material 9 Support rod 10 Cooling unit 11 Lifting means 12 Soaking unit

Claims (4)

A chuck top having a chuck top conductor layer on the surface, a soaking plate made of a high heat conductive material provided on the back side opposite to the wafer mounting surface of the chuck top, and disposed between the chuck top and the soaking plate. It comprises a cushion material having low rigidity, a bottomed cylindrical support that supports the chuck top, and a heating body provided on the back side of the heat equalizing plate so as not to contact the support, and the heat equalizing plate is -55. The support body has an outer diameter of 95% or more with respect to the outer diameter of the chuck top in a temperature range of ℃ to 200 ° C, and the support has a plurality of protrusions that are in contact with and supported by the outer periphery of the back surface of the chuck top A notch groove M1 is provided, and the heat equalizing plate and the cushion material are provided with a plurality of notch grooves M2 so as not to contact the protrusions of the support, and the heat equalizing plate and the cushion. Material and heating element It is installed so as to fill the cutaway slot M1 of the total area of the cutout slot M1 of the support, characterized in that at least 50% of the total area of the notch slot M2 of the homogeneous hot plate Wafer holder for wafer probers. Wherein the rear surface side of the soaking plate, characterized in that it comprises a cooling controllable cooling unit, wafer holding body according to claim 1. The wafer holder for a wafer prober according to claim 2 , wherein the soaking plate and the cooling unit are integrated. Wafer prober, characterized in that mounting the wafer holding body according to any one of claims 1-3.

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