KR20010029094A - Method of cooling wafer stage in a wafer probe station - Google Patents

Abstract

PURPOSE: A method for cooling a stage of an equipment for testing a wafer is provided to prevent a decrease of equipment efficiency, in which the decrease is caused because the temperature of the stage is not easily changed from a high temperature to a room temperature when the wafer is tested at the high temperature and the room temperature in the equipment. CONSTITUTION: An air spraying apparatus is installed in an equipment for testing a wafer, in which the air spraying apparatus forcibly and uniformly supplies coolant air to the entire surface of a stage on which the wafer is placed.

Description

Method of cooling wafer stage in a wafer probe station

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stage cooling method of a wafer inspection equipment, and more particularly, to a method of cooling a stage on which a wafer is placed in a wafer probe inspection equipment used for inspecting a function in a semiconductor device step formed on a wafer.

Wafers go through a variety of processes for manufacturing semiconductor devices. Therefore, the required device is formed on the wafer in units of chips. In this state, the wafer is cut into chips to form individual semiconductor devices through packaging. However, not all chips on the wafer are normally formed, and in some cases, repairs are necessary or discarded. Inspecting and removing these parts from the finished product through packaging is unreasonable and wasteful. Therefore, once the semiconductor device is entirely or partially formed on the wafer, the semiconductor device is inspected by connecting the element elements with a probe without dividing the semiconductor device into chip units. Such inspection devices are often referred to as prober systems. In this inspection equipment, the wafer must be placed in the correct position for accurate inspection of the semiconductor device, and the place where the wafer is placed is called a stage. The stage mainly consists of chucks.

This wafer inspection is not only done at room temperature, but also at significant temperatures, such as 80 ° C or 110 ° C, to ensure the stability of the peripherals while the chip is actually operating. In order to inspect at such high temperatures, the temperature of the wafer must be increased, which in turn increases the temperature of the stage on which the wafer is placed. In order to increase the temperature of the stage, all the parts of the wafer must have an even and accurate temperature at the time of inspection.

By the way, increasing the temperature of the stage can be carried out easily and quickly by using a heating device such as a heater, but lowering the temperature took more than several times to several tens of times the heating time in the current inspection equipment. For example, heating from room temperature to 110 ° C takes several minutes to ten minutes, but conversely, cooling takes up to two or three hours. Therefore, the efficiency and effectiveness of the equipment at the inspection stage becomes a problem.

According to the present invention, the time required for lowering the temperature of the stage on which the wafer is placed to inspect another wafer at room temperature after heating to confirm functionality at high temperature in the semiconductor device probe inspection at the wafer stage is too high. It aims to provide a new cooling method for wafer inspection equipment that can improve the problem of deteriorating its own operation rate and effectiveness.

1 and 2 are side and bottom views of stage cooling apparatus that may be used to practice the present invention.

3 is a side view showing another cooling device for carrying out the method of the present invention.

4 is a configuration diagram showing a state in which an air inlet is installed so that cooling air can be applied to a vacuum chuck with heating equipment in a wafer inspection facility.

※ Explanation of symbols for main parts of drawing

10: air tube 20: air inlet

30, 60: body 40: legs

50: air nozzle 80: fan

90: electric lead wire 100: motor

110: chuck 111: hole

120, 160: controller 130: electric wire

140: heating wire 170: valve

171: air piping 172: vacuum piping

180: timer

The cooling method of the present invention for achieving the above object is characterized in that the air injection device is installed so as to forcibly supply the cooling air evenly to the front surface of the stage on which the wafer is placed in the wafer inspection equipment.

In the present invention, the method for supplying the cooling air evenly may have a disk-shaped body provided with a plurality of injection holes for spraying the inlet for the outside air and the upper surface of the stage on which the wafer is placed. It may be a device for selectively supplying the air for cooling and vacuum depending on the process by connecting the air for cooling to the vacuum chuck forming.

In addition, it may not be a method of distributing external air, but may be a method of directly installing a motor and a fan to send cooling air to the front of the stage on which the wafer is placed.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. 1 and 2 are side and bottom views of stage cooling apparatus that may be used to practice the present invention. The stage cooling device as a whole, the main body 30 is a disk-like or short cylindrical made of a metal such as copper, a plurality of air inlet 50 is formed on the lower surface of the main body 30, the air inlet 20 is It is installed and connected to the external air supply tube. And in the center is installed a separate air tube 10 having a valve upwards. The air tube is divided into four parts so that each end is positioned toward the lower stage from the periphery of the body. The air tube 10 can be further separated into the desired number. The air tube 10 has a variable structure made of an iron tube or a soft metal. And four legs 40 are installed on the lower surface so that the main body 30 is placed on the stage. On the lower surface of the main body 30, the air injection hole 50 is provided in the vertex part and center of a regular hexagon.

Figure 3 shows another cooling apparatus for carrying out the method of the present invention. The short cylindrical body 60 is provided with a fan 80 and a motor 100 capable of supplying cooling air directly above the stage. And instead of the outside air inlet is provided with an electric lead wire 90 to supply power to the motor (100). A plurality of air injection holes may be formed on the lower surface of the main body 60, but instead, the front surface is opened so that the air from the fan 80 can be supplied evenly to the front surface of the stage. Although the leg 40 is formed in the main body 60 here, the whole body is installed in the arm which can be moved in parallel, and may take the form which supplies cooling air to the required part according to the movement of an arm.

4 shows a state in which an air inlet is installed so that cooling air can be applied to a heating chuck for raising the temperature of the wafer from room temperature to high temperature in a wafer inspection facility. In this example, the cooling air is supplied through the air pipe 171 and is connected to the heating chuck 110 through the valve 170 to be selectively applied with the vacuum supplied through the vacuum pipe 172. A plurality of holes 111 are formed on the upper surface of the 110 to serve as an air injection hole to which a vacuum for holding a wafer is applied or air for cooling the heating chuck is supplied. Whether to apply a vacuum or cooling air to the chuck 110 in the valve 170 is controlled through a controller 160 formed separately from the controller 120 for supplying current to the heating wire 140 and the process proceeds. Timer 180 is connected with the controller 160 for.

In the above, the controller for controlling the current supply and the valve for applying the cooling air and the timer may be integrally formed together, and the air and vacuum may be applied by supplying the controller to branch and adjust the valve from the controller that sends the current to the heating wire. You can also adjust.

According to the present invention, when the wafer is inspected while alternating the high temperature and the normal temperature in the wafer inspection equipment, the temperature of the stage on which the wafer is placed does not easily change from a high temperature to a normal temperature, thereby reducing the efficiency of the equipment.

Claims (3)

A stage cooling method of a wafer inspection equipment, characterized by providing an air injector so as to forcibly supply cooling air to the front surface of the stage on which the wafer is placed in the wafer inspection equipment. The method of claim 1, The stage cooling device has a main body portion of a disk or a short cylindrical shape, a plurality of air injection holes are formed on the lower surface, the air inlet is installed on the side is connected to the external air supply tube, the central portion having a valve upwards A separate air tube is installed so that the air tube is separated into a plurality of stages, each end is positioned so as to face the stage to the periphery of the main body, the stage cooling method of the wafer inspection equipment, characterized in that it takes a variable structure. The method of claim 1, The stage consists of a heating vacuum chuck to increase the temperature of the wafer, the cooling air is connected to the heating chuck through a valve to be selectively applied with the vacuum, the vacuum hole for holding the wafer on the upper surface of the heating chuck is It is installed to act as an air inlet when air is supplied, the stage of the wafer inspection equipment, characterized in that the controller is connected with a timer to control whether to apply the vacuum or air to the heating chuck in the valve Cooling method.