Temperature adjustment method and inspection device for mounting table

Abstract

The present invention provides a temperature control method and inspection device for a stage. The substrate mounting surface of the stage is divided into a plurality of regions, and heaters are respectively provided for the plurality of regions. The temperature control method comprises: a step of feedback controlling the heater of a main region corresponding to the device to be inspected among the plurality of regions so that the temperature of the main region becomes a set temperature; and a step of controlling the heater of a sub-region adjacent to the main region among the plurality of regions on the substrate mounting surface. In the step of controlling the heater of the sub-region, when the temperature of the main region does not overshoot, the heater of the sub-region is controlled so that the temperature difference between the main region and the sub-region becomes a specified value, and when the temperature of the main region overshoots, the heater of the sub-region is controlled so that the difference between the set temperature and the temperature of the sub-region becomes a specified value. According to the present invention, the heat absorption performance of the stage from the device to be inspected can be improved without causing the stage to warp.

Description

Technical Field

[0001] The present disclosure relates to a temperature adjustment method and an inspection device for a mounting table. Background Art

[0002] Patent document 1 discloses a heater for an inspection device. The heater is provided with a heating element inside a substrate, and the substrate is formed into a disc-shaped substrate as a whole by combining a plurality of sections. As each section, there is a disc-shaped section and a wide disc-shaped section provided in a manner of surrounding the periphery of the disc-shaped section. In addition, Patent document 1 discloses that a temperature measuring element is installed in each section of the substrate, and temperature control is performed for each section.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-184558 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The technology disclosed in the present invention is to improve the performance of absorbing heat from the inspection target device by the mounting table without causing warping of the mounting table.

[0008] Methods used to solve problems

[0009] One embodiment of the present invention is a temperature control method for adjusting the temperature of a mounting table for mounting a substrate in an inspection device for inspecting an inspection object device formed on a substrate, wherein a substrate mounting surface of the mounting table is divided into a plurality of areas, and heaters are respectively provided for the plurality of areas, the temperature control method comprising: a step of feedback controlling the heater of a main area corresponding to the inspection object device among the plurality of areas so that the temperature of the main area becomes a set temperature; and a step of controlling the heater of a sub-area adjacent to the main area among the plurality of areas on the substrate mounting surface, in the step of controlling the heater of the sub-area, when the temperature of the main area does not overshoot, controlling the heater of the sub-area so that the temperature difference between the main area and the sub-area becomes a specified value, and when the temperature of the main area overshoots, controlling the heater of the sub-area so that the difference between the set temperature and the temperature of the sub-area becomes a specified value.

[0010] Effects of the Invention

[0011] According to the present disclosure, the performance of absorbing heat from the inspection target device by the mounting table can be improved without causing warping of the mounting table. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view schematically showing the structure of the inspection device according to the present embodiment.

[0013] Figure 2 It is a front view schematically showing the structure of the inspection device according to this embodiment.

[0014] Figure 3 It is a cross-sectional view schematically showing the structure of the mounting table.

[0015] Figure 4 It is a plan view schematically showing the structure of the heating unit.

[0016] Figure 5 It is a block diagram schematically showing the outline of the configuration of the control unit.

[0017] Figure 6 It is a block diagram schematically showing the outline of the configuration of the heating control unit.

[0018] Description of Reference Numerals

[0019] 1. Inspection device

[0020] 10 Loading table

[0021] 13. Control Unit

[0022] 110a Wafer mounting surface

[0023] 120 Heating unit

[0024] 121 Heater

[0025] D Inspection target device

[0026] Tm Main Zone Temperature

[0027] Ts The temperature of the sub-region

[0028] Tt set temperature

[0029] W chip

[0030] Zm main area

[0031] Zs sub-region DETAILED DESCRIPTION

[0032] In the manufacturing process of semiconductor devices (hereinafter referred to as "devices"), multiple devices are simultaneously formed on a substrate such as a semiconductor wafer (hereinafter referred to as "wafer"). The formed devices are inspected for electrical characteristics and the like, and are screened into qualified products and unqualified products. The inspection of the device is performed, for example, using an inspection device in the state of the substrate before being divided into individual devices.

[0033] In addition, in the inspection apparatus, in order to be able to inspect the electrical characteristics of the device at high and low temperatures, there is also an apparatus in which a heater and a cooling mechanism are provided on the mounting table on which the substrate is mounted.

[0034] When a heater is provided on the stage, the substrate mounting surface of the stage is sometimes divided into a plurality of regions, and a heater is provided in each region (for example, see Patent Document 1). In this case, for example, the temperature of each region of the substrate mounting surface is measured, and the heater is feedback-controlled so that each region reaches a set temperature, so that the temperature of the substrate mounting surface is uniform within the substrate surface. Hereinafter, such control is referred to as overall uniform control.

[0035] However, in recent years, in the inspection of logic integrated circuits as devices, the devices have become more integrated and faster, and the heat generated has increased, so it is impossible to inspect the devices formed on the substrate at once. Therefore, it has become the mainstream to inspect each device or every few devices.

[0036] However, when inspecting each device or every several devices, if the above-mentioned overall uniform control is performed, the area where the device to be inspected is located and the surrounding area are isothermal, so the heat of the surrounding area becomes a heat load, and the heat absorption performance of the mounting table from the device to be inspected is reduced. As a result, when the device to be inspected generates rapid heat, the temperature of the area where the device to be inspected is located on the substrate mounting surface may greatly exceed the set temperature.

[0037] In addition, as a method for controlling the temperature of the substrate mounting surface of the mounting table, in addition to the above, there is also the following method: only in the area where the device to be inspected is located on the substrate mounting surface, the heater is feedback controlled in the same manner as above, and the heater is turned off in other areas. Hereinafter, such control is referred to as local concentrated control. In this local concentrated control, the heat absorption performance of the mounting table from the device to be inspected is improved compared with the above-mentioned overall uniform control, but only the area where the device to be inspected is located on the substrate mounting surface becomes high temperature, and the mounting table will be warped. As a result, it is sometimes impossible to perform accurate electrical characteristic inspection.

[0038] Therefore, the technology disclosed in the present invention is to improve the performance of the mounting table in absorbing heat from the device under inspection without causing the mounting table to warp.

[0039] Hereinafter, the temperature adjustment method and inspection device of the mounting table according to the present embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional structure are denoted by the same reference numerals, and repeated description of these elements will be omitted.

[0040] First, the structure of the inspection device according to this embodiment will be described. Figure 1 and Figure 21 and 2 are respectively a perspective view and a front view schematically showing the structure of the inspection device 1 of this embodiment. Figure 2 In order to express Figure 1 Components built into a storage chamber and a loader, which will be described later, of the inspection device 1 are partially shown in cross section.

[0041] The inspection device 1 inspects the electrical characteristics of a device (not shown) formed on a wafer W as a substrate. A plurality of n (n is a natural number greater than 2) devices are formed on the wafer W, and the inspection device 1 inspects m (m is a natural number less than n) devices simultaneously in one inspection. In addition, the number of devices to be inspected is assumed to be 1. Figure 1 and Figure 2 As shown, the inspection apparatus 1 includes: a storage chamber 2 for storing wafers W during inspection; a loader 3 arranged adjacent to the storage chamber 2; and a tester 4 arranged to cover the upper side of the storage chamber.

[0042] like Figure 2 As shown, the storage chamber 2 is a housing having a hollow interior and has a stage 10 for placing a wafer W. The stage 10 absorbs and holds the wafer W so that the position of the wafer W relative to the stage 10 does not shift. In addition, the stage 10 is configured to be movable in the horizontal direction and the vertical direction. With this structure, the relative position of the probe card 11 described later and the wafer W can be adjusted so that the electrodes on the surface of the wafer W are in contact with the probes 11a of the probe card 11.

[0043] A probe card 11 is disposed above the mounting table 10 in the storage chamber 2 so as to face the mounting table 10. The probe card 11 has probes 11a that are in electrical contact with electrodes of devices formed on the wafer W or the like.

[0044] The probe card 11 is connected to the tester 4 via the interface 12. Each probe 11a contacts an electrode of each device formed on the wafer W during electrical property inspection, supplies power from the tester 4 to the tester via the interface 12, and transmits a signal from the device to the tester 4 via the interface 12.

[0045] The loader 3 takes out wafers W stored in a FOUP (not shown) as a transport container and transports them to the stage 10 of the storage chamber 2. The loader 3 also receives wafers W after the electrical characteristics inspection of the device is completed from the stage 10 and stores them in the FOUP.

[0046] Furthermore, the loader 3 has a control unit 13 that performs various controls such as temperature control of the mounting table 10. The control unit 13, which is also called a basic unit, is composed of, for example, a computer including a CPU, a memory, etc., and has a program storage unit (not shown). Programs for controlling various processes in the inspection device 1 are stored in the program storage unit. In addition, the above-mentioned program is recorded in a computer-readable storage medium and can also be installed from the storage medium to the control unit 13. Part or all of the program can also be implemented by dedicated hardware (circuit board). The control unit 13 is connected to the mounting table 10 via a wiring 14, for example, and controls the heating unit 120 described later based on the temperature of the top plate 110 described later of the mounting table 10. In addition, the control unit 13 can also be arranged in the storage room 2.

[0047] The tester 4 has a test board (not shown) for reproducing a part of the circuit structure of the motherboard on which the device is mounted. The test board is connected to a test computer 15 for judging whether the device is qualified or not based on the signal from the device formed on the wafer W. In the tester 4, by replacing the test board, the circuit structure of various motherboards can be reproduced.

[0048] Furthermore, the inspection apparatus 1 includes a user interface 16 for displaying information to the user or for the user to input instructions. The user interface 16 is composed of, for example, an input unit such as a touch panel or a keyboard, and a display unit such as a liquid crystal display.

[0049] In the inspection apparatus 1 having the above-mentioned components, when inspecting the electrical characteristics of the device formed on the wafer W, the test computer 15 sends data to the test board connected to the device via the probes 11a. Then, the test computer 15 determines whether the sent data is correctly processed by the test board based on the electrical signal from the test board.

[0050] Next, use Figure 3 and Figure 4 The structure of the mounting table 10 will be described. Figure 3 It is a cross-sectional view schematically showing the structure of the mounting table 10 . Figure 4 It is a plan view schematically showing the structure of a heating unit 120 to be described later.

[0051] like Figure 3 As shown, the mounting table 10 is formed by stacking a plurality of functional parts including a heating part 120. The mounting table 10 is mounted on a moving mechanism (not shown) that moves the mounting table 10 in the horizontal direction and the vertical direction via a heat insulating part 20. The heat insulating part 20 is made of, for example, resin, graphite, ceramics with low thermal conductivity, etc.

[0052] The mounting table 10 includes a top plate 110 , a heating unit 120 , and a cooling unit 130 in this order from the top.

[0053] The top plate 110 is a member whose upper surface 110a serves as a wafer mounting surface serving as a substrate mounting surface for mounting the wafer W. In addition, hereinafter, the upper surface 110a of the top plate 110 serving as the upper surface of the mounting table 10 is sometimes referred to as the wafer mounting surface 110a. The top plate 110 is formed, for example, in a disk shape. In addition, the top plate 110 is made of a material having a high thermal conductivity and a high Young's modulus, and is formed thinner so as to have a smaller heat capacity. By reducing the heat capacity of the top plate 110, for example, the temperature of the top plate 110 can be changed at a high speed by heating of the heating unit 120. In addition, as a material for the top plate 110, for example, ceramics such as SiC and AlN are used, and in the case where it is necessary to further suppress the manufacturing cost, metals such as copper and aluminum are used.

[0054] In addition, if Figure 4 As shown, the wafer mounting surface 110a of the top plate 110 is divided into a plurality of regions. Specifically, the wafer mounting surface 110a is divided into, for example, a circular first region Z1 located at the center in a plan view and second to fourth regions Z2 to Z4 that divide the circular region surrounding the first region Z1 into three equal parts.

[0055] Furthermore, the top plate 110 has a temperature sensor T10 in the first area Z1, temperature sensors T20 to T22 in the second area Z2, temperature sensors T30 to T32 in the third area Z3, and temperature sensors T40 to T42 in the fourth area Z4. That is, if the temperature sensors T10, T20 to T22, T30 to T32, and T40 to T42 are respectively set as temperature sensors T, the top plate 110 has at least one temperature sensor T in each of the areas Z1 to Z4 of the wafer mounting surface 110a. Each temperature sensor T measures the temperature of a portion of the wafer mounting surface 110a where the temperature sensor T is provided. In addition, the temperature sensor T10 is provided, for example, at the center of the top plate 110. The temperature sensors T20 to T22, T30 to T32, and T40 to T42 are provided, for example, at equal intervals on the same circumference centered on the center of the top plate 110.

[0056] The heating unit 120 is a component for heating the top plate 110. Figure 3 As shown in the figure, the heating unit 120 is arranged between the top plate 110 and the cooling unit 130, in other words, it is arranged at a position closer to the wafer mounting surface 110a than the cooling unit 130. The heating unit 120 has a built-in resistance heating element that generates heat by power supply. The resistance heating element is formed of tungsten, for example. In addition, although the figure is omitted, an insulating layer formed of an insulating material such as mica and polyimide, and an electromagnetic shielding layer formed of a material with high conductivity such as a metal material are provided between the heating unit 120 and the top plate 110.

[0057] In addition, if Figure 4As shown, the heating unit 120 includes heaters 121 disposed in the first to fourth zones Z1 to Z4 of the top plate 110, respectively. 1 ~121 4 Heater 121 1 ~121 4 The above-mentioned resistance heating elements are respectively built in and are configured to be independently controllable.

[0058] In addition, the heater 121 1 The heater 121 is formed into a circular shape in plan view in accordance with the shape of the first area Z1 of the corresponding wafer mounting surface 110a. 2 ~121 4 The second to fourth regions Z2 to Z4 of the corresponding wafer mounting surface 110 a are formed into arc ring shapes in plan view.

[0059] Below, sometimes the heater 121 1 ~121 4 They are respectively abbreviated as heaters 121.

[0060] like Figure 3 As shown, the cooling unit 130 is provided below the heating unit 120. The cooling unit 130 is a component for cooling the top plate 110, and is formed in a disk shape, for example. A flow path 131 for the flow of the refrigerant is formed inside the cooling unit 130. A port 132 is connected to the side of the cooling unit 130. Figure 4 As shown, the port 132 has a supply port 132 a for supplying the refrigerant to the flow path 131 and a discharge port 132 b for discharging the refrigerant from the flow path 131 .

[0061] As the refrigerant, for example, a fluorine-based liquid, a liquid such as ethylene glycol, or a gas such as nitrogen can be used.

[0062] Although not shown in the figure, an electromagnetic shielding layer made of a material with high conductivity such as a metal material is provided between the cooling unit 130 and the heating unit 120 .

[0063] The heating unit 120 and the cooling unit 130 configured as described above are controlled by the control unit 13 .

[0064] Next, use Figure 5 The configuration of the control unit 13 for controlling the heating unit 120 and the cooling unit 130 will be described. Figure 5 It is a block diagram schematically showing the outline of the configuration of the control unit 13 .

[0065] like Figure 5 As shown, the control unit 13 includes a storage unit 13a, a main region determination unit 13b, a sub-region determination unit 13c, a temperature acquisition unit 13d, a heating control unit 13e, and a cooling control unit 13f.

[0066] The storage unit 13a stores various information. For example, the storage unit 13a stores the set temperature of the main zone Zm, etc. In addition, the storage unit 13a stores the deviation amount described later when the first to fourth zones Z2 to Z4 of the wafer mounting surface 110a are sub-zones.

[0067] The main region determination unit 13b determines the main region Zm corresponding to the inspection target device D from the first to fourth regions Z1 to Z4 of the wafer mounting surface 110a of the mounting table 10. For example, based on the information of the center of gravity position of the inspection target device D, the main region determination unit 13b determines the region overlapping with the center of gravity position of the inspection target device D in the first to fourth regions Z1 to Z4 as the main region Zm. Figure 4 In the example, the third area Z3 is determined to be the main area Zm.

[0068] The sub-region judging unit 13c judges the sub-region Zs adjacent to the main region Zm from the first to fourth regions Z1 to Z4 of the wafer mounting surface 110a of the mounting table 10 based on the judgment result of the main region judging unit 13b. For example, when the first region Z1 is the main region Zm, the second to fourth regions Z2 to Z4 are judged to be the sub-region Zs, and when the second region Z2 is the main region Zm, the first, third, and fourth regions Z1, Z3, and Z4 are judged to be the sub-region Zs.

[0069] The temperature acquisition unit 13d acquires the temperature of each of the first to fourth regions Z1 to Z4 of the wafer mounting surface 110a of the mounting table 10. Specifically, the temperature acquisition unit 13d acquires the temperature of each of the first to fourth regions Z1 to Z4 of the wafer mounting surface 110a of the mounting table 10 based on the measurement result of the temperature sensor T.

[0070] More specifically, the temperature acquisition unit 13 d acquires, for example, the measurement result of the temperature sensor T10 as the temperature of the first zone Z1 .

[0071] In addition, the temperature acquisition unit 13d, for example, obtains the average value of the measurement results of the temperature sensors T20~T22 as the temperature of the second zone Z2. Similarly, it obtains the average value of the measurement results of the temperature sensors T30~T32 as the temperature of the third zone Z3, and obtains the average value of the measurement results of the temperature sensors T40~T42 as the temperature of the fourth zone Z4.

[0072] The temperature acquisition unit 13d may also acquire the temperature of the portion where the inspection target device D is located in the main area Zm among the first to fourth areas Z1 to Z4 (hereinafter sometimes referred to as "device location temperature") as the temperature of the area. The device location temperature Td is calculated based on, for example, the measurement results of a plurality of temperature sensors T around the inspection target device D and the weighting corresponding to the distance of each of these temperature sensors T from the inspection target device D. In the above weighting, the closer to the inspection target device D, the greater the weight is. Figure 4 In the example, based on the measurement results t30, t32, t10 of the three temperature sensors T30, T32, T10 close to the inspection object device D and the distances r30, r32, r10 from the temperature sensors T30, T31, T10 to the inspection object device D, the device position temperature Td is calculated according to the following formula (1).

[0073] Td=(r30·r1·t32+r32·r10·t30+r32·r30·t10) / (r30·r10+r32·r10+r32·r30)…(1)

[0074] The heating control unit 13e controls the heating unit 120, specifically, the heaters 1211 to 1214 of the heating unit 120, based on the determination results of the main region determination unit 13b and the sub-region determination unit 13c and the acquisition result of the temperature acquisition unit 13d. The heating control unit 13e will be described in detail later.

[0075] The cooling control unit 13 f controls the cooling unit 130 . Specifically, the cooling control unit 13 f controls the temperature and flow rate of the coolant flowing through the flow path 131 of the cooling unit 130 based on the set temperature of the mounting table 10 .

[0076] In this embodiment, under the control of the heating control unit 13e and the cooling control unit 13f, the cooling unit 130 cools the entire wafer mounting surface 110a while adjusting the heating amount of the heating unit 120 for each region of the wafer mounting surface 110a. Even when a device formed on the wafer W suddenly heats up during the electrical characteristics inspection, the cooling unit 130 is always performed to cool the device so that the heat of the device can be quickly absorbed.

[0077] Next, use Figure 6 The configuration of the heating control unit 13e will be described. Figure 6 It is a block diagram schematically showing the outline of the configuration of the heating control unit 13e.

[0078] like Figure 6 As shown, the heating control unit 13e includes a main zone control unit 201 and sub-zone control units 202 to 204.

[0079] The main area control unit 201 controls the heater 121 of the main area Zm determined by the main area determination unit 13b. Specifically, the main area control unit 201 performs feedback control on the heater 121 of the main area Zm so that the temperature Tm of the main area Zm becomes the set temperature Tt of the main area Zm as the control target temperature. In other words, the main area control unit 201 performs control calculation to adjust the operation amount of the heater 121 of the main area Zm. Therefore, the main area control unit 201 has: a deviation calculator 201a, which calculates the deviation Δt1 of the temperature Tm of the main area Zm obtained by the temperature acquisition unit 13d relative to the set temperature Tt; and a controller 201b, which performs control calculation (for example, PID calculation) based on the above deviation Δt1 to calculate and output the operation amount of the heater 121 of the main area Zm. In addition, hereinafter, "set temperature" means "set temperature of the main area Zm".

[0080] The sub-region control units 202 to 204 each control the heater 121 of one of the sub-regions Zs determined by the sub-region determination unit 13c. The sub-regions Zs that the sub-region control units 202 to 204 control are different from each other.

[0081] The control performed by the sub-zone control units 202 to 204 is different between when the temperature Tm of the main zone Zm does not overshoot and when it overshoots. The overshoot occurs when the device under inspection D generates heat, for example.

[0082] The sub-region control unit 202 includes a deviation calculator 202 a and a controller 202 b .

[0083] When the temperature Tm of the main zone Zm does not overshoot, the sub-zone control unit 202 performs feedback control on the heater 121 of the sub-zone Zs so that the temperature difference (Tt-Tm) between the main zone Zm and the sub-zone Zs to be controlled by the sub-zone control unit 202 becomes the deviation α with respect to the sub-zone Zs. In other words, the sub-zone control unit 202 performs control operation to adjust the operation amount of the heater 121 of the sub-zone Zs. Specifically, when the temperature Tm of the main zone Zm does not overshoot, the sub-zone control unit 202 causes the deviation calculator 202a to calculate the deviation Δt2 between the temperature difference (Tm-Ts) between the main zone Zm and the sub-zone Zs and the deviation α based on the temperature Tm of the main zone Zm acquired by the temperature acquisition unit 13d and the temperature Ts of the sub-zone Zs to be controlled and the deviation α. ​​Then, the controller 202b performs control operation (for example, PID operation) based on the deviation Δt2 to calculate and output the operation amount of the heater 121 of the sub-zone Zs to be controlled.

[0084] When the temperature Tm of the main zone Zm overshoots, the sub-zone control unit 202 performs feedback control on the heater 121 of the sub-zone Zs so that the temperature difference between the set temperature Tt and the temperature Ts of the sub-zone Zs to be controlled by the sub-zone control unit 202 becomes the above-mentioned deviation α with respect to the sub-zone Zs. Specifically, when the temperature Tm of the main zone Zm overshoots, the sub-zone control unit 202 causes the deviation calculator 202a to calculate the deviation Δt2 between the difference (Tt-Ts) between the set temperature Tt and the temperature Ts of the sub-zone Zs to be controlled and the above-mentioned deviation α, and then the controller 202b performs control calculation (for example, PID calculation) based on the above-mentioned deviation Δt2, and calculates and outputs the operation amount of the heater 121 of the sub-zone Zs to be controlled.

[0085] The configurations of the sub-region control units 203 and 204 are the same as that of the sub-region control unit 202 , and thus description thereof will be omitted.

[0086] The deviation amount α is set so that heat does not flow from the sub-region Zs to the main region Zm and warping does not occur on the wafer mounting surface 110a of the mounting table 10. As described above, the deviation amount α is set so that warping does not occur on the wafer mounting surface 110a of the mounting table 10, and therefore changes according to the Young's modulus and thickness of the top plate 110, for example.

[0087] The deviation α may be different for each region. In addition, the deviation α is basically a negative value, but can be a positive value depending on the structure of the mounting table 10. For example, a positive value may be set as the deviation α only for the third region Z3 that is close to the port 132 and is easier to cool than other regions.

[0088] In addition, the amount of deviation when each area is the sub-area Zs may differ depending on which area the main area Zm is.

[0089] As described above, the control performed by the sub-zone control unit 202 and the like is different between the case where the temperature Tm of the main zone Zm does not overshoot and the case where the temperature Tm overshoots.

[0090] Whether or not the temperature Tm of the main zone Zm has overshot is determined by, for example, the heating control unit 13 e .

[0091] In addition, whether the temperature Tm of the main area Zm has overshot is determined, for example, based on whether the temperature Tm of the main area Zm exceeds a reference temperature Tb (Tb ≥ Tt) determined based on the set temperature Tt. For example, if the temperature Tm exceeds the reference temperature Tb, it is determined that an overshoot has occurred, and if the temperature Tm does not exceed the reference temperature Tb, it is determined that no overshoot has occurred.

[0092] Whether the temperature Tm of the main zone Zm has overshot can also be determined based on whether the temperature Tm of the main zone Zm exceeds the reference temperature Tb and whether the operation amount of the heater 121 of the main zone Zm is 0. For example, if the temperature Tm exceeds the reference temperature Tb and is 0, it is determined that overshoot has occurred, and otherwise it is determined that overshoot has not occurred.

[0093] In addition, whether the temperature of the main zone Zm has overshot may be determined based on whether the operation amount of the heater 121 in the main zone Zm is 0. For example, if it is 0, it is determined that overshoot has occurred, and if it is not 0, it is determined that no overshoot has occurred.

[0094] Which information is used to determine whether the temperature Tm of the main zone Zm has overshot is determined by the user based on the content of the control calculation performed by the controller 201 b of the main zone control unit 201 , for example.

[0095] Next, an example of the inspection process using the inspection device 1 will be described.

[0096] In the inspection process, first, the wafer W is taken out from the FOUP of the loader 3 and transported and mounted on the mounting table 10. Then, the mounting table 10 moves, and the probes 11a provided above the mounting table 10 contact the electrodes of the inspection target devices of the wafer W.

[0097] Then, a signal for inspection is input to the probe 11a. Thus, the electrical characteristic inspection of the inspection target device is started. When the electrical characteristic inspection is completed, the stage 10 moves and the next inspection target device on the wafer W is subjected to the same process.

[0098] Thereafter, the above-mentioned process is repeatedly performed until the electrical characteristics inspection of all devices is completed.

[0099] It should be noted that, in the above-mentioned electrical characteristic inspection, the temperature of the inspection object device is required to be a desired temperature. Therefore, for example, during the electrical characteristic inspection and before and after the electrical characteristic inspection, the temperature acquisition unit 13d always acquires the temperature of the first to fourth zones Z1 to Z4 of the wafer mounting surface 110a. Then, based on the acquired set temperature Tt and deviation α of the first to fourth zones Z1 to Z4, the heating control unit 13e performs feedback control of the heater 121 of the first to fourth zones Z1 to Z4, and based on the set temperature Tt, the cooling control unit 13f controls the cooling unit 130. In this way, the temperature of the mounting table 10 is adjusted so that the temperature of the inspection object device D is maintained at a desired temperature.

[0100] The heating control of the temperature regulation method of the mounting table 10 in the present embodiment includes: (A) a step of feedback controlling the heater 121 of the main area Zm corresponding to the inspection object device D among the areas Z1 to Z4 on the chip mounting surface 110a so that the temperature of the main area Zm becomes the set temperature Tt; and (B) a step of controlling the heater 121 of the sub-area Zs adjacent to the main area Zm among the areas Z1 to Z4 on the chip mounting surface 110a.

[0101] Furthermore, in the above-mentioned step (B), (a) when the temperature Tm of the main zone Zm does not overshoot, the heater 121 of the sub-zone Zs is controlled for each sub-zone Zs so that the temperature difference (Tm-Ts) between the main zone Zm and the sub-zone Zs becomes the deviation α with respect to the sub-zone Zs, and (b) when the temperature Tm of the main zone Zm overshoots, the heater 121 of the sub-zone Zs is controlled for each sub-zone Zs so that the difference (Tt-Ts) between the set temperature Tt and the temperature Ts of the sub-zone Zs becomes the above-mentioned deviation α.

[0102] Since the control is performed as described in (a) above, when the device under inspection D rapidly heats up, the amount of heat absorbed from the device under inspection D via the sub-region Zs increases compared to the above-described overall uniform control.

[0103] In addition, the case where no overshoot occurs in the temperature Tm of the main region Zm refers to the case where the temperature Tm of the main region Zm is below the set temperature Tt. In such a case, in the present embodiment, control is performed as in (a) above. That is, the control of the heater 121 of the sub-region Zs is not performed in a manner that the temperature of the sub-region Zs follows the set temperature Tt, but in a manner that the temperature of the sub-region Zs follows the temperature Tm of the main region Zm which is lower than the set temperature Tt. Thus, heat inflow from the sub-region Zs to the main region Zm can be prevented. Therefore, in the present embodiment, compared with the case where the heater 121 of the sub-region Zs is controlled in a manner that the temperature of the sub-region Zs follows the set temperature Tt, the amount of heat absorbed from the inspection object device D via the sub-region Zs becomes greater.

[0104] On the other hand, the case where the temperature Tm of the main region Zm overshoots refers to the case where the temperature Tm of the main region Zm is higher than the set temperature Tt. In such a case, in the present embodiment, control is performed as in (b) above. That is, the control of the heater 121 of the sub-region Zs is not performed in a manner that the temperature of the sub-region Zs follows the temperature Tm of the main region Zm, but in a manner that the temperature of the sub-region Zs follows the set temperature Tt that is lower than the temperature Tm of the main region Zm. Therefore, in the case where the temperature Tm of the main region Zm overshoots, the heat of the main region Zm can be released to the sub-region Zs. That is, when the temperature Tm of the main region Zm overshoots, the amount of heat absorbed from the inspection object device D via the sub-region Zs becomes greater. Therefore, overshooting can be further prevented.

[0105] Furthermore, since the control is performed as described above in (a) and (b), warping does not occur on the mounting table 10 as in the case of the above-described local concentrated control.

[0106] Therefore, according to the present embodiment, it is possible to improve the heat absorption capability via the mounting table 10 without causing warping of the mounting table 10 .

[0107] According to the present embodiment, since the heat absorption capability via the mounting table 10 is high, even when the inspection target device D generates heat rapidly, the temperature can be returned to a desired temperature in a short time.

[0108] Furthermore, according to the present embodiment, since the mounting table 10 does not warp as described above, the contact resistance between the probe 11 a and the device under inspection D does not change due to the warping of the mounting table 10 , and thus the electrical characteristics inspection of the device under inspection D can be appropriately performed.

[0109] Furthermore, according to the present embodiment, it is possible to prevent the probe card 11 from being damaged due to the warping of the mounting table 10 .

[0110] In addition, according to the present embodiment, the temperature Ts of the sub-region Zs is closer to the temperature Tm of the main region Zm than in the above-mentioned local concentrated control. Therefore, when the inspection object device D is switched and the main region Zm is switched to the region that was the sub-region Zs, in the present embodiment, the inspection object device D can be brought to a desired temperature at a higher speed than in the above-mentioned local concentrated control.

[0111] As described above, the temperature acquisition unit 13d may acquire, as the temperature Tm of the main region Zm, a device position temperature Td calculated based on the measurement results of the plurality of temperature sensors T around the inspection target device D and weights corresponding to the distances of each of these temperature sensors T from the inspection target device D. By performing feedback control on the heater 121 as the main region Zm as described in (A) above based on the device position temperature Td as the temperature Tm of the main region Zm, the inspection target device D can be made to reach a desired temperature more accurately.

[0112] By increasing the number of temperature sensors T, the device position temperature Td becomes more accurate, so the inspection target device D can be set to a desired temperature more accurately.

[0113] In addition, by dividing the wafer mounting surface 110a more finely and increasing the number of heaters 121, the inspection target device D can be set to a desired temperature more accurately. However, in the case where an IC temperature sensor is used as the temperature sensor T, it costs more to increase the number of heaters 121 than to increase the number of temperature sensors T. Therefore, for example, by increasing the number of temperature sensors T instead of the number of heaters 121, it is possible to achieve a more accurate desired temperature of the inspection target device at a low cost.

[0114] In addition, in the present embodiment, the heating unit 120 is provided at a position closer to the wafer mounting surface 110a than the cooling unit 130, that is, the cooling unit 130 is not provided between the heating unit 120 and the wafer mounting surface 110a. Therefore, since the heat capacity of the heating unit 120 is small, the heating unit 120 can be heated with good responsiveness.

[0115] In the above description, the heating unit 120 is provided below the top plate 110 via an electromagnetic shielding layer, etc., but the heating unit may be provided in the top plate. In this case, when a material with high conductivity such as tungsten is used as the heating element of the heating unit, the base material of the top plate is formed of a material with high electrical insulation and thermal conductivity such as aluminum nitride.

[0116] Furthermore, in the present embodiment, the wafer mounting surface 110a is divided into a plurality of regions, and the wafer mounting surface 110a is heated from a position closer to the cooling unit 130 by using the heater 121 provided in each region according to the temperature of the region. Thus, the local temperature change of the wafer mounting surface 110a is dealt with by heating each region by the heating unit 120 having good responsiveness. In addition, by absorbing heat from the entire wafer mounting surface 110a by using the cooling unit 130 together with the above-mentioned heating, it is also possible to deal with local heating during the electrical characteristics inspection of a device with high heat density.

[0117] It should be noted that the prior art is different from the present embodiment in that only one of cooling and heating is performed, and in addition, the top plate of the mounting table is made thicker to increase the heat capacity. Furthermore, when the device under inspection generates heat, the heat capacity of the top plate is used to absorb the heat. However, in recent years, the heat density of devices has increased, and the method of the prior art cannot maintain a device with a high heat density at a desired temperature.

[0118] On the other hand, according to the present embodiment, as described above, even for a device with a high heat density, local heat generation during an electrical characteristics test can be dealt with and maintained at a desired temperature.

[0119] In the above example, when the wafer mounting surface 110a is divided into a plurality of regions, each region is either the main region Zm or the adjacent sub-region Zs. However, depending on the division method of the wafer mounting surface 110a, the regions that divide the wafer mounting surface 110a may include a region that is neither the main region Zm nor the sub-region Zs. In this case, the heater 121 of the region that is neither the main region Zm nor the sub-region Zs may be controlled in the same manner as the heater 121 of the main region Zm, or in the same manner as the heater 121 of the sub-region Zs.

[0120] It should be understood that the embodiments disclosed in this application are illustrative in all points and are not limiting. In addition, the above-mentioned embodiments may be omitted, replaced, and modified in various ways without departing from the claims and the gist thereof.

Claims

1. A temperature control method for controlling the temperature of a mounting table for mounting a substrate in an inspection device for inspecting an inspection target device formed on a substrate, wherein: The substrate mounting surface of the mounting table is divided into a plurality of regions, and heaters are respectively provided for the plurality of regions. The temperature adjustment method comprises: A step of feedback-controlling the heater of a main area corresponding to the inspection target device among the plurality of areas so that the temperature of the main area becomes a set temperature, wherein the set temperature is a control target temperature of the main area; and a step of controlling the heater of the sub-region adjacent to the main region in the plurality of regions on the substrate mounting surface, In the step of controlling the heater of the sub-zone, When the temperature of the main region does not overshoot, the heater of the sub-region is controlled so that the temperature difference between the main region and the sub-region becomes a deviation amount, When the temperature of the main region overshoots, the heater of the sub-region is controlled so that the difference between the set temperature and the temperature of the sub-region becomes the deviation amount. The deviation amount is set in such a manner that heat does not flow from the sub-region to the main region and warping does not occur on the substrate mounting surface. Whether the temperature of the main region has overshot is determined based on whether the temperature of the main region exceeds a reference temperature determined based on the set temperature.

2. The temperature adjustment method according to claim 1, characterized in that: Whether the temperature of the main area has overshot is determined based on whether the operation amount of the heater in the main area is zero.

3. The temperature adjustment method according to claim 1 or 2, characterized in that: The mounting table includes a cooling unit for cooling the substrate mounting surface of the mounting table. The heater is disposed at a position closer to the substrate mounting surface than the cooling unit.

4. The temperature adjustment method according to claim 1 or 2, characterized in that: The mounting table has at least one temperature sensor in each of the plurality of regions. The temperature adjustment method further includes the step of acquiring, as the temperature of the main area, the temperature of a portion of the main area where the inspection target device is located. This step acquires the temperature of the portion where the device under inspection is located in the main region based on the measurement results of the plurality of temperature sensors around the device under inspection and weights corresponding to the distances of the temperature sensors from the device under inspection.

5. An inspection device for inspecting an inspection target device formed on a substrate, characterized in that: include: A mounting table for mounting a substrate; and Control Department, The substrate mounting surface of the mounting table is divided into a plurality of regions, and heaters are respectively provided for the plurality of regions. The control unit, Feedback control is performed on the heater of the main area corresponding to the inspection target device among the plurality of areas so that the temperature of the main area becomes a set temperature, wherein the set temperature is a control target temperature of the main area, and controlling the heater of the sub-region adjacent to the main region in the plurality of regions on the substrate mounting surface, When controlling the heater of the sub-zone, When the temperature of the main region does not overshoot, the heater of the sub-region is controlled so that the temperature difference between the main region and the sub-region becomes a deviation amount, When the temperature of the main region overshoots, the heater of the sub-region is controlled so that the difference between the set temperature and the temperature of the sub-region becomes the deviation amount. The deviation amount is set in such a manner that heat does not flow from the sub-region to the main region and warping does not occur on the substrate mounting surface. The control unit determines whether the temperature of the main region has overshot based on whether the temperature of the main region exceeds a reference temperature determined based on the set temperature.

6. The inspection device according to claim 5, characterized in that: The control unit further determines whether the temperature of the main region has overshot based on whether the operation amount of the heater in the main region is zero.

7. The inspection device according to claim 5 or 6, characterized in that: The mounting table includes a cooling unit for cooling the substrate mounting surface of the mounting table. The heater is disposed at a position closer to the substrate mounting surface than the cooling unit.

8. The inspection device according to claim 5 or 6, characterized in that: The mounting table has at least one temperature sensor in each of the plurality of regions. The control unit obtains the temperature of the portion of the main area where the inspection object device is located as the temperature of the main area. At this time, the temperature of the portion of the main area where the inspection object device is located is obtained based on the measurement results of the multiple temperature sensors around the inspection object device and the weighting corresponding to the distance of each temperature sensor from the inspection object device.

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