WO2009113749A1

WO2009113749A1 - Wafer testing system comprising chiller

Info

Publication number: WO2009113749A1
Application number: PCT/KR2008/001499
Authority: WO
Inventors: Myung-Koo Kang; Chan-Min Park; Kun-Su Kang
Original assignee: Semics Inc.
Priority date: 2008-03-12
Filing date: 2008-03-17
Publication date: 2009-09-17
Also published as: KR100888054B1; JP2011514008A; JP5269107B2

Abstract

A wafer test system including a wafer prober device having a chuck is provided. The wafer test system includes: a dry air supply device receiving compressed air and dehumidifying the compressed air; a cooling device including a container for storing liquefied gas; and a central control device cooling dry air supplied from the dry air supply device, mixing the cooled dry air with a predetermined amount of the liquefied gas stored in the container, and supplying the mixture to the chuck of the wafer prober device. Accordingly, the wafer test system has refrigeration efficiency optimized for testing a wafer in an ultra-low temperature environment by using the wafer prober device, thereby reducing a preparation time for testing the wafer in the ultra-low temperature environment.

Description

[DESCRIPTION] [Invention Title]

WAFER TESTING SYSTEM COMPRISING CHILLER [Technical Field]

The present invention relates to a wafer test system including a cooler, and more particularly, to a wafer test system including a cooler and a wafer prober device so as to easily test a wafer in an ultra-low temperature environment. [Background Art]

A conventional wafer prober device generally includes a chuck for conveying a wafer to a proper position, X and Y stages for directly conveying the chuck, and a loader unit for moving a wafer loaded on a cassette onto the chuck. The wafer prober device is used to check an electrical defect of an individual chip generated on a wafer produced in a procedure of manufacturing a semiconductor device.

In addition, the wafer prober device additionally includes various devices so as to check reliability of an environment for the wafer in addition to the aforementioned basic test.

Specifically, in order to test the wafer in an ultra-low temperature environment, a cooling device for lowering a temperature of the wafer is indispensable for a conventional wafer prober device.

The cooling device uses a two-stage cooler and a single-stage cooler which are sold in the past. However, it is difficult to expect that a general-use cooler has a standard and a function optimized for testing a wafer in an ultra-low temperature environment by using the wafer prober device.

In addition, the cooling device lowers the temperature of the wafer by circulating liquid coolant into the chuck.

However, since the wafer prober device that employs the aforementioned method lowers the temperature of the chuck by directly using the cooled liquid coolant, cooling efficiency is high. However, in a case where the liquid coolant circulating the chuck is leaked, the liquid coolant may damage the wafer and components of the wafer prober device. In addition, in order to remove the danger caused by the aforementioned method, one of conventional wafer prober devices uses air instead of the liquid coolant as a fluid circulating the chuck.

However, in the wafer prober device, since the air has a lower specific heat than the liquid coolant, it takes much time to cool the wafer.

Although it is possible that the cooler is in operation at all times so as to reduce the time taken to cool the wafer, it is economically inefficient to continuously operating the cooler so as to test the wafer in the ultra-low temperature environment. [Disclosure] [Technical Problem]

The present invention provides a wafer test system with refrigeration efficiency optimized for a test in an ultra-low temperature environment capable of reducing a preparation time for a test in the ultra-low temperature environment. [Technical Solution]

According to an aspect of the present invention, there is provided a wafer test system including a wafer prober device having a chuck for locating a wafer, the wafer test system comprising: a dry air supply device receiving compressed air, dehumidifying the compressed air, and externally supplying the dehumidified air; a cooling device that includes a container for storing liquefied gas, the cooling device cooling the air supplied from the dry air supply device, supplying the cooled air, and supplying the liquefied gas stored in the container; a user input unit including a rapid cooling mode key for selecting a rapid cooling mode for rapidly lowering a temperature of the chuck; and a central control device operating in a general cooling mode for controlling the cooling device so that the air that is supplied from the dry air supply device is cooled and supplied to the chuck of the wafer prober device and in a rapid cooling mode for controlling the cooling device so that the air supplied from the dry air supply device is cooled, mixed with a predetermined amount of the liquefied gas stored in the container, and supplied to the chuck of the wafer prober device when the rapid cooling mode is selected through the rapid cooling mode key.

In the above aspect of the present invention, the wafer prober device may include a cooling channel formed in the chuck, and the central control device may control the cooling device so that the air supplied from the dry air supplying device is cooled and supplied to the cooling channel and control the cooling device so that the air cooled by the cooling device is mixed with a predetermined amount of the liquefied gas stored in the container and supplied to the cooling channel when the rapid cooling mode is selected.

Here, the cooling device may include a general cooling module cooling the air supplied from the dry air supply device, a rapid cooling module including the container and supplying the liquefied gas stored in the container, and a cool air supply module supplying the air that is cooled by the general cooling module and the liquefied gas supplied by the rapid cooling module to the cooling channel, and the central control device may control the general cooling module so that the air supplied from the dry air supply device is cooled and supplied to the cool air supply module, control the cool air supply module so that the air supplied by the general cooling module is supplied to the cooling channel, control the rapid cooling module so that a predetermined amount of the liquefied gas is supplied to the cool air supply module when the rapid cooling mode is selected, and control the cool air supply module so that the liquefied gas supplied by the rapid cooling module is supplied to the cooling channel.

In addition, the temperature control module of the wafer prober device may include a temperature sensor for sensing a temperature of the chuck, and when the rapid cooling mode is selected through the user input unit, the central control device may calculate an amount of the liquefied gas supplied to the cooling channel in consideration of the temperature of the chuck sensed by the temperature sensor and control the cooling device so that the calculated amount of the liquefied gas is supplied to the cooling channel.

In addition, the user input unit may include a temperature selection key for selecting the temperature of the chuck, the temperature control module of the wafer prober device includes a heating member for heating the chuck, and the central control device may control the cooling device and the heating member so that the temperature of the selected chuck is the same as the temperature of the chuck sensed by the temperature sensor when the temperature of the chuck is selected through the temperature selection key. In addition, the wafer prober device may include a housing for enclosing surrounding air of the chuck and an internal air supply module for supplying air passing through the cooling channel into the housing, and the central control device may control the internal air supply module so that the air passing through the cooling channel is supplied into the housing. In addition, the temperature control module may include a dew point sensor for sensing a dew point temperature of the surrounding air of the chuck, and the central control device may control the internal air supply module so that the temperature of the chuck sensed by the temperature sensor is compared with the dew point temperature sensed by the dew point sensor and so that an amount of air supplied into the wafer prober device is adjusted based on the comparison result. Here, the liquefied gas stored in the container may be liquefied nitrogen. [Advantageous Effects]

As described above, it is possible for the wafer test system according to an embodiment of the present invention to provide cooling efficiency optimized for a test in an ultra-low temperature environment by being embodied as a system in which a refrigerating device optimized not for a general-use cooler but for a wafer prober device is integrated.

In addition, since the wafer test system according to an embodiment of the present invention cools a chuck by using gas coolant instead of liquid coolant in a cooling channel, it is possible to reduce a danger caused by leakage of the liquid coolant.

In addition, since a rapid cooling mode in which a small amount of liquefied nitrogen is sprayed, mixed with cool air, and used is embodied in the wafer test system according to an embodiment of the present invention, it is possible to considerably reduce a time taken to prepare a test of a wafer in an ultra-low temperature environment.

In addition, it is possible for the wafer test system according to an embodiment of the present invention to prevent dew generated in a housing when testing a wafer in an ultra-low temperature environment by reusing air that is used to cool a chuck by spraying the air into the housing. [Description of Drawings] FIG. 1 is a schematic block diagram illustrating a wafer test system according to an embodiment of the present invention.

FIG. 2 is a schematic block diagram illustrating a flow of air in the wafer test system according to the embodiment of the present invention.

FIG. 3 is a flowchart illustrating a procedure in which a central control device according to the embodiment of the present invention tests a wafer in an ultra-low temperature environment.

FIG. 4 is a flowchart illustrating a procedure in which the central control device according to the embodiment of the present invention prevents dew while testing a wafer in the ultra-low temperature environment. [Best Mode]

Hereinafter, a structure and an operation of a wafer test system according to an embodiment of the present invention will be described in detail with reference to the attached drawings.

A wafer test system 1 according to an embodiment of the present invention schematically includes a wafer prober device 300 capable of testing a thermal environment of a wafer and a cooling unit for providing a low temperature environment. As shown in FIG. 1, the wafer test system 1 according to the embodiment includes a dry air supply device 100, a cooling device 200, a wafer prober device 300, a user input unit 400, and a central control device 500.

The wafer prober device 300 according to the embodiment of the present invention operates in two modes so as to test a wafer in an ultra-low environment. A first operation mode is a general cooling mode that is performed by cooling air that is supplied from the dry air supply device 100 and supplying the cooled air to the wafer prober device 300. A second operation mode is a rapid cooling mode that is performed by cooling air supplied from the dry air supply device 100 by mixing a predetermined amount of liquefied gas supplied from a rapid cooling module 230 with cooled air supplied from a general cooling module 210 and supplying the cooled air to the wafer prober device 300.

A structure of the wafer test system 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic block diagram illustrating the wafer test system 1 according to the embodiment of the present invention. FIG. 2 is a schematic block diagram illustrating a flow of air in the wafer test system 1 according to the embodiment of the present invention.

First, the dry air supply device 100 serves to receive compressed air, dehumidify the compressed air, and supply the dehumidified air to the cooling device 200.

As shown in FIG. 1, the dry air supply device 100 may be constructed with an air compressor 120 and an air drier 110. The air compressor 120 supplies internal compressed air. The air drier 110 serves to dry the supplied air. The air drier 110 dries the supplied air by using an absorbent. Accordingly, the dry air supply device 100 may generate dry air at a temperature of about 20 °C .

Here, the dry air is cooled by the cooling device 200 and used as a medium for lowering a temperature of a chuck 310 included in the wafer prober device 300.

The cooling device 200 cools the air supplied from the dry air supply device 100 and supplies the cooled air. The cooling device 200 includes a container for storing the liquefied gas. The liquefied gas stored in the container 231 is supplied to the wafer prober device 300 under a control of the central control device 500.

As shown in FIG. 1 , the cooling device 200 may be constructed with a general cooling module 210, a cool air supply module 220, a rapid cooling module 230, and the container 231.

As shown in FIG. 2, the general cooling module 210 may be constructed with a refrigerator 211 and a heat exchanger 212. The general cooling module 210 cools the air supplied from the dry air supply device 100 and supplies the cooled air. Here, the refrigerator 211 may use a two-stage or single-stage refrigerator capable of lowering a temperature of coolant below a temperature ranging from -80 ^°C to -90 ^°C . The heat exchanger 212 cools the air supplied from the dry air supply device 100 through a heat exchanging method by using coolant cooled by the refrigerator 211 and supplies the cooled air to the cool air supply module 220. The heat exchanger 212 can cool the supplied air to a temperature of about -70 ^°C . Since the refrigerator 211 and the heat exchanger 212 are known, detailed description on them will be omitted. The rapid cooling module 230 that includes the container 231 for containing the liquefied gas supplies the liquefied gas stored in the container 231 to the cool air supply module 220 under a control of the central control device 500. Here, liquefied nitrogen is generally used as the liquefied gas. The container 231 is made of a heat resistant material tolerable under an ultra-low temperature (about -190^°C).

The cool air supply module 220 supplies the air cooled by the general cooling module 210 or the liquefied gas supplied by the rapid cooling module 230 to the wafer prober device 300 under a control of the central control device 500.

The wafer prober device 300 serves to test whether a semiconductor wafer is defective. The wafer prober device 300 includes a chuck 310 for placing a wafer to be tested, X and Y stage units (not shown) for moving and fixing the chuck 310, a prober unit (not shown) for providing an electrical connection with the wafer to be tested and transmitting and receiving an electrical signal, a tester (not shown) for suitably testing each wafer by using a program for checking whether each wafer is manufactured according to a predetermined specification by using the electrical signal transmitted and received from the prober unit (not shown), and a loader (not shown) for moving a wafer from a cassette (not shown) in which a plurality of wafers are inserted to the chuck 310 of the stage unit (not shown). Since these components are known, detailed description on these components will be omitted.

For convenience, FIG. 2 illustrates only a part of the wafer prober device 300. This is because this part is related to a test in an ultra-low temperature environment according to the embodiment of the present invention.

The wafer prober device according to an embodiment of the present invention includes the chuck 310, a temperature control module 311, an internal air supply module 320, and a housing 330.

The chuck 310 located in the housing 330 serves as a location board for locating and fixing a wafer. A cooling channel 310a is formed in the chuck 310. Here, the chuck 310 serves to transfer heat to the wafer.

The cooling channel 310a is formed so that the cool air and liquefied gas supplied from the cool air supply module 220 of the cooling device 200 pass through the inside of the chuck 310 so as to lower the temperature of the chuck 310. The cooling channel 310a may be formed in various manners so that heat of the chuck 310 is effectively transferred.

The temperature control module 311 controls the temperature of the chuck 310. The temperature control module 311 includes a heating member 311a, a temperature sensor 311b, and a dew point sensor 311c.

The heating member 311a is formed under the cooling channel 310a so as to increase the temperature of the chuck 310. Heat is generated by applying a source voltage to the heating member 311a. The applying of the source voltage is controlled by the central control device 500.

The temperature sensor 311b senses the temperature of the chuck 310 and transmits the temperature of the chuck 310 to the central control device 500. The dew point sensor 311c senses the dew point temperature of surroundings of the chuck 310 and transmits the dew point temperature of the surroundings of the chuck 310 to the central control device 500.

The internal air supply module 320 supplies internal air into the housing 330 under a control of the central control device 500. That is, the internal air supply module 320 supplies the air passing through the cooling channel 310a into the housing 330. In addition, the internal air supply module 320 includes an outlet (not shown) for discharging some of the air passing through the cooling channel 31 Oa to the outside of the housing 330. Accordingly, it is possible to control an amount of air supplied into the housing 330.

The housing 330 provides a closed space for testing a wafer in an ultra-low temperature environment. While testing the wafer in the ultra-low temperature environment, dew is prevented from being formed on the wafer by preventing external air from being introduced into the housing 330.

A user input unit 400 is constructed with a rapid cooling mode key 410 and a temperature selection key 420.

Here, the rapid cooling mode key 410 is used to select a rapid cooling mode for rapidly lowering the temperature of the chuck 310. When the user selects the rapid cooling mode key 410, the wafer test system 1 according to the embodiment operates in the rapid cooling mode. Here, the rapid cooling mode key 410 may be prepared in various types such as a button switch and a touch screen in which a user interface is embodied.

The temperature selection key 420 is used to select the temperature of the chuck 310. A control signal corresponding to the selected temperature of the chuck 310 is transmitted to the central control device 500. Here, the temperature of the chuck 310 is set to about -80 ^°C so as to test a wafer in an ultra-low temperature environment.

The central control device 500 includes a low temperature setting module (not shown) and a dew prevention module (not shown) so as to test a wafer in the ultra-low temperature environment.

Here, the low temperature setting module (not shown) may be constructed with a rapid cooling mode and a general cooling mode.

That is, when the rapid cooling mode is not selected through the user input unit 400, that is, in case of a general cooling mode, the central control device 500 controls the cooling device 200 so as to cool the air supplied from the dry air supply device 100 and supply the cooled air to the chuck 310 of the wafer prober device 300.

In case of the general cooling mode, when the refrigerator 211 operates, the coolant of the low temperature side is cooled down to a temperature ranging from -80 ^°C to -90 ^°C , and the dry air supplied from the dry air supply device 100 is cooled down below a temperature of -70 ^°C . The central control device 500 controls the cool air supply module 220 so that the cooled dry air is supplied to the cooling channel 31 Oa of the chuck 310 of the prober device 300.

In a case where the rapid cooling mode is selected through the user input unit 400, that is, in case of the rapid cooling mode, the central control device 500 controls the cooling device 200 so that some of the liquefied gas stored in the container 231 and cooled air supplied from the general cooling module 210 are mixed and supplied to the chuck 310 of the wafer prober device 300. Here, liquefied nitrogen is used as the liquefied gas.

In case of the rapid cooling mode, the central control device 500 controls the rapid cooling module 230 so that some of the liquefied gas stored in the container 231 is supplied to the cool air supply module 220. The liquefied gas is leaked from the container 231 and vaporized at the same time to be mixed with the cool air supplied from the general cooling module 210. An amount of the liquefied gas supplied from the rapid cooling module 230 is less than that of the air supplied from the general cooling module 210. That is, the amount of the liquefied gas may be a tenth of that of the air.

Next, the central control device 500 controls the cool air supply module 220 so that the liquefied gas supplied by the rapid cooling module 230 is supplied to the cooling channel 310a of the chuck 310.

In addition, the central control device 500 calculate an amount of the supplied liquefied gas in consideration of the temperature of the chuck 310 sensed by the temperature sensor 311b of the temperature control module 311. That is, the central control device 500 adjusts an amount of the liquefied gas within a range between about a twelfth and an eighth of the amount of the air in correspondence with the sensed temperature of the chuck 310 and supplies the liquefied gas to the cool air supply module 220.

In addition, when the temperature of the chuck 310 is selected through the temperature selection key 420, the central control device 500 controls the cooling device 200 and the heating member 311a so that the selected temperature of the chuck 310 is the same as the temperature of the chuck 310 sensed by the temperature sensor 311b.

As is not shown in FIG. 2, in order to allow the central control device to control a flow of fluid, as described above, the cooling device 200 and the wafer prober device 300 have to include a switching member such as an ultra-low temperature valve or fluid valve (not shown). The central control device 500 controls the flow of fluid of the cooling device 200 and the wafer prober device 300 by driving the switching member.

Hereinafter, a procedure of controlling the low temperature setting module (not shown) and the dew prevention module (not shown) by using the central control device 500 will be described with reference to FIGS. 3 and 4.

Hereinafter, the low temperature setting module and the dew prevention module will be described with reference to FIGS. 3 and 4.

FIG. 3 is a flowchart illustrating a procedure in which the central control device 500 tests a wafer in an ultra-low temperature environment. First, the central control device 500 receives a temperature that is set through the temperature selection key 420 and stores the received temperature in a memory (operation SlOO).

Here, a case where the set temperature is -60 °C is exemplified. This indicates that the wafer test system 1 starts to test a wafer at an ultra-low temperature of -60 ^°C .

Next, the central control device 500 receives a current temperature of the chuck 310 and a dew point temperature of surroundings of the chuck 310 and stores the current temperature and the dew point temperature in the memory (operation SI lO). This procedure is periodically performed so as to monitor the current state of the chuck 310.

Next, the central control device 500 executes the low temperature setting module by controlling the cooling device 200 (operation S 120). That is, the central control device 500 cools coolant of a low temperature side of the refrigerator to a temperature of about -80 ^°C by driving the general cooling module 210. Then, the central control device 500 operates so that the air cooled through the heat exchanger 212 cools the air supplied from the dry air supply device 100 to a temperature of -70 "C and supplies the air to the cool air supply module 220.

In addition, the central control device 500 performs the aforementioned operation S 120 and a control procedure of FIG. 4, at the same time. In the control procedure of FIG. 4, the dew prevention module is executed. Description on the control procedure will be described later.

Next, the central control device 500 determines whether the rapid cooling mode is selected (operation S 130). This depends on whether the rapid cooling mode key 410 is selected. Here, the rapid cooling mode is divided into a manual mode and an automatic mode. In FIG. 3, only the automatic mode will be described. The manual mode will be described later.

Next, if the rapid cooling mode is not selected in operation S 130, operation S 150 is performed.

Alternatively, when the rapid cooling mode is selected in operation S 130, the central control device 500 calculates a temperature of the chuck 310 and determines whether a difference between the set temperature that is stored in operations SlOO and SI lO and the temperature of the chuck 310 is equal to or less than 5 ^°C (operation S 140).

Next, as the determination result of operation S 140, if the difference in temperature is equal to or less than 5 ^°C, the central control device 500 performs operation S 150.

Alternatively, as the determination result of operation S 140, if the difference in temperature is greater than 5 "C, the central control device 500 executes the rapid cooling module 230 (operation S145). That is, as the difference in temperature becomes greater than 5 ^°C, the central control device 500 controls the rapid cooling module 230 so that a supply of liquefied nitrogen is increased. For example, in a case where a current temperature of the chuck is sensed at 100 ^°C and a low temperature setting temperature is -60 ^°C , the rapid cooling module 230 supplies the liquefied nitrogen of which amount is about an eighth of an amount of the air supplied to the cool air supply module 220 to the cool air supply module 220. In a case where the current temperature of the chuck is -20 ^°C, the rapid cooling module 230 reduces the supply of the liquefied nitrogen to a twelfth of the amount of the air supplied to the cool air supply module 220.

Here, the amount of the liquefied nitrogen with respect to the difference in temperature may be stored in a memory as a lookup table or calculated in real time according to a predetermined calculation equation.

Next, as the determination result of operation S 140, if the difference in temperature is equal to or less than 5 ^°C , the central control device 500 supplies the cool air that is supplied to the cool air supply module 220 in the previous procedures to the cooling channel 310a of the chuck 310 (operation S150).

Next, the central control device 500 determines whether the current temperature of the chuck 310 that is stored in the aforementioned operations SlOO and SI lO is higher than the set temperature (operation S 160).

Next, as the determination result of operation S 160, if the current temperature of the chuck 310 is higher than the set temperature, the central control device 500 returns to operation S 140. Alternatively, as the determination result of operation S 160, if the current temperature of the chuck 310 is lower than the set temperature, the central control device 500 drives the heating member 311a and returns to operation S 160 (operation S 170).

As described above, in a case where the rapid cooling mode is selected, since the central control device 500 rapidly lowers the temperature of the chuck 310 by supplying liquefied nitrogen, it is possible to considerably reduce a preparation time for testing a wafer in an ultra-low temperature environment.

The manual mode will be briefly described independently of the automatic mode of the wafer test system according to the embodiment of the present invention.

If the rapid cooling mode is selected through the rapid cooling mode key 410, the central control device 500 recognizes the selection of the rapid cooling mode, performs a previously set sequence regardless of the current temperature of the chuck 310 and the dew point temperature of surroundings of the chuck 310, and completes the sequence. That is, the general cooling module 210 is driven, thereby supplying cool air to the cool air supply module 220. The supplied cool air is supplied to the cooling channel 310a of the chuck 310, again. At the same time, the rapid cooling module 230 is driven, thereby supplying the liquefied nitrogen of which amount is a tenth of the amount of the air supplied to the cool air supply module 220 to the cool air supply module 220. The liquefied nitrogen is vaporized by the air supplied to the cool air supply module 220 and supplied to the cooling channel 310a by using the cool air supply module 220.

Hereinafter, the dew prevention module (not shown) will be described with reference to FIG. 4.

FIG. 4 is a flowchart illustrating a procedure in which the central control device 500 prevents dew while testing a wafer in the ultra-low temperature environment.

First, the central control device 500 reads a current temperature of the chuck 310 that is monitored in the aforementioned operation SI lO and the dew point temperature of surroundings of the chuck 310 and subtracts the dew point temperature of the surroundings of the chuck 310 from the current temperature of the chuck 310 (operation S200). That is, it is determined whether a difference between the temperature of the chuck 310 and the dew point temperature of the surroundings of the chuck 310 is equal to or less than +10 ^"C .

Next, as the determination result of operation S200, if the difference between the temperature of the chuck 310 and the dew point temperature is equal to or less than +10^°C, the central control device 500 controls the internal air supply module 320 so that the entire air passing through the cooling channel 310a is supplied into the housing 330 (operation S210).

Alternatively, as the determination result of operation S200, if the difference between the temperature of the chuck 310 and the dew point temperature is greater than +10^°C, the central control device 500 controls the supply module 320 so that half the air passing through the cooling channel 310a is supplied into the housing 330 and the other half is discharged to the outside of the housing 330 by opening an outlet (not shown) (operation S220).

As described above, it is possible to prevent dew occurring in the housing 330 when testing a wafer in an ultra-low temperature environment by allowing the central control device 500 to reuse the air that is used to cool the chuck 310 by spraying the air into the housing 330 of the wafer prober device 300. [Industrial Applicability]

The wafer test system according to an embodiment of the present invention may be effectively used to test a semiconductor device and manufacture a semiconductor device.

Claims

[CLAIMS] [Claim 1 ]

A wafer test system including a wafer prober device having a chuck for locating a wafer, the wafer test system comprising: a dry air supply device receiving compressed air, dehumidifying the compressed air, and supplying the dehumidified air to the outside of the dry air supply device; a cooling device that includes a container for storing liquefied gas, the cooling device cooling the air supplied from the dry air supply device, supplying the cooled air, and supplying the liquefied gas stored in the container; a user input unit including a rapid cooling mode key for selecting a rapid cooling mode for rapidly lowering a temperature of the chuck; and a central control device operating in a general cooling mode for controlling the cooling device so that the air that is supplied from the dry air supply device is cooled and supplied to the chuck of the wafer prober device and in a rapid cooling mode for controlling the cooling device so that the air supplied from the dry air supply device is cooled, mixed with a predetermined amount of the liquefied gas stored in the container, and supplied to the chuck of the wafer prober device when the rapid cooling mode is selected through the rapid cooling mode key. [Claim 2]

The wafer test system of claim 1, wherein the wafer prober device includes a cooling channel formed in the chuck, and wherein the central control device controls the cooling device so that the air supplied from the dry air supplying device is cooled and supplied to the cooling channel and controls the cooling device so that the air cooled by the cooling device is mixed with a predetermined amount of the liquefied gas stored in the container and supplied to the cooling channel when the rapid cooling mode is selected. [Claim 3]

The wafer test system of claim 2, wherein the cooling device includes a general cooling module cooling the air supplied from the dry air supply device, a rapid cooling module including the container and supplying the liquefied gas stored in the container, and a cool air supply module supplying the air that is cooled by the general cooling module and the liquefied gas supplied by the rapid cooling module to the cooling channel, and wherein the central control device controls the general cooling module so that the air supplied from the dry air supply device is cooled and supplied to the cool air supply module, controls the cool air supply module so that the air supplied by the general cooling module is supplied to the cooling channel, controls the rapid cooling module so that a predetermined amount of the liquefied gas is supplied to the cool air supply module when the rapid cooling mode is selected, and controls the cool air supply module so that the liquefied gas supplied by the rapid cooling module is supplied to the cooling channel. [Claim 4]

The wafer test system of claim 2, wherein the temperature control module of the wafer prober device includes a temperature sensor for sensing a temperature of the chuck, and wherein when the rapid cooling mode is selected through the user input unit, the central control device calculates an amount of the liquefied gas supplied to the cooling channel in consideration of the temperature of the chuck sensed by the temperature sensor and controls the cooling device so that the calculated amount of the liquefied gas is supplied to the cooling channel. [Claim 5]

The wafer test system of claim 4, wherein the user input unit includes a temperature selection key for selecting the temperature of the chuck, wherein the temperature control module of the wafer prober device includes a heating member for heating the chuck, and wherein the central control device controls the cooling device and the heating member so that the temperature of the selected chuck is the same as the temperature of the chuck sensed by the temperature sensor when the temperature of the chuck is selected through the temperature selection key. [Claim 6]

The wafer test system of claim 5, wherein the wafer prober device includes a housing for enclosing surrounding air of the chuck and an internal air supply module for supplying air passing through the cooling channel into the housing, and wherein the central control device controls the internal air supply module so that the air passing through the cooling channel is supplied into the housing. [Claim 7]

The wafer test system of claim 6, wherein the temperature control module includes a dew point sensor for sensing a dew point temperature of the surrounding air of the chuck, and wherein the central control device controls the internal air supply module so that the temperature of the chuck sensed by the temperature sensor is compared with the dew point temperature sensed by the dew point sensor and so that an amount of air supplied into the wafer prober device is adjusted based on the comparison result. [Claim 8]

The wafer test system of claim 1 , wherein in the cooling device, the liquefied gas stored in the container is liquefied nitrogen.