JPH0312949A - Wafer carrier holding device - Google Patents

Abstract

PURPOSE:To prevent a wafer from being charged with electric charges independently of the material of a wafer carrier by providing a wafer contact part such that at least one end of the wafer in the wafer carrier makes contact with the wafer contact part upon placing the wafer carrier. CONSTITUTION:A conductive or semiconductive wafer contact part 3 is provided such that one end of a wafer 5 placed on a wafer carrier 4 makes contact with the wafer carrier 4. For this, even though the wafer carrier 4 is charged with static electricity after processing and hence static electricity is induced on the wafer 5, when the wafer carrier 4 on which the wafer 5 is placed is placed on a wafer carrier holding device 1, the static electricity on the wafer 5 can be removed through the wafer contact part by earthening the wafer 5 contact part. Hereby, the material of the wafer carrier 4 comprises an insulator material, e.g. Teflon liable to be charged, the wafer 5 can be prevented from being charged in storage thereof irrespective of the material.

Description

[Detailed Description of the Invention] (Summary) Regarding a wafer carrier holding device, the present invention provides a wafer carrier holding device that can prevent wafers from being charged regardless of the material of the wafer carrier when storing wafers loaded on the wafer carrier. A wafer carrier holding device for holding a wafer carrier, comprising: a wafer contact portion so that at least one end of a wafer in the wafer carrier contacts when the wafer carrier is placed; do.

[Industrial application field] The present invention relates to a wafer carrier holding device.

In recent years, the miniaturization of semiconductor devices has progressed further, and yields are increasingly affected by dust adhesion to wafers.

Dust adhesion to wafers occurs during wafer processing or wafer storage. In particular, it is necessary to store the wafer for a long time between processing steps, and in this case, there are many opportunities for dust to adhere to the wafer surface. Therefore, in order to improve yield, it is important to prevent dust from adhering to wafers during storage.

[Conventional technology]

Conventionally, when storing wafers, the wafers were loaded onto Teflon wafer carriers that can be directly treated with chemical solutions, placed in storage boxes, and stored while maintaining a clean environment.

[Problem to be solved by the invention]

By the way, since the wafer carrier is made of an insulator,
Static electricity is easily induced in the wafer carrier during processing steps and remains as it is.

Therefore, if the wafers are stored as they are without being transferred after processing, static electricity will be induced in the loaded wafers.

Therefore, if the wafer is stored for a long time, dust in the storage box will accumulate on the surface of the wafer. For example, if the wafer is left in a storage box maintained in a clean atmosphere of Class 10 for 20 hours, approximately 100 pieces of dust with a size of 0.2 μm or more will adhere to the wafer surface. Confirmed with a detection device.

For this reason, there is a problem in that particularly when the pattern is made finer, the yield decreases significantly.

In order to solve this problem, the wafer contact part is provided by mixing a conductive substance such as carbon into the Teflon material of the wafer carrier or by coating the surface of the wafer carrier with a conductive substance. This is accomplished by a wafer carrier holding device.

[For production]

In the wafer carrier holding device of the present invention, a conductive or semiconductive wafer contact portion is provided so that one end of a wafer loaded on the wafer carrier comes into contact with the wafer carrier.

Therefore, even if the wafer carrier is charged with static electricity after processing and, as a result, static electricity is induced on the wafer, when the wafer carrier loaded with wafers is placed on the wafer carrier holding device, the wafer contact part is grounded. By doing so, static electricity on the wafer can be removed via the wafer contact portion.

Thereby, even if the material of the wafer carrier is an insulating material that is easily charged, such as Teflon, charging of the wafer during storage can be prevented regardless of the material.

It is possible to prevent static electricity from being induced.

However, when chemical processing is performed using this wafer carrier, the conductive material on the surface of the wafer carrier is exposed to the chemical.
There is a problem that the wafer carrier becomes unusable.

Therefore, when performing chemical treatment, it is necessary to transfer the wafer to a Teflon wafer carrier. However, when transferring wafers, there is a problem in that the chances of dust generation are further increased.

The present invention was made in view of such conventional problems, and
It is an object of the present invention to provide a wafer carrier holding device that can prevent wafers from being charged regardless of the material of the wafer carrier when the wafers are stored on a wafer carrier.

(Means for Solving the Problem) The above problem is to provide a wafer carrier holding device on which a wafer carrier is placed, so that at least one end of the wafer in the wafer carrier comes into contact with the wafer carrier when the wafer carrier is placed on the wafer carrier. Conductive Examples Next, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a wafer carrier holding device according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a stainless steel holding stand on which a wafer carrier (not shown) is placed, and numeral 2 stands for stainless steel holding stands provided at the four corners of the holding stand 1 to fix the wafer carrier in a predetermined position. guide, 3 is holding stand 1
Approximately 2 cm wide and 1 cm high, located approximately in the center of
The wafer contact part is about the same length as the wafer carrier, and is made of carbon-containing Teflon with a resistivity of 105 Ωcm, and when the wafer carrier loaded with wafers is placed,
It is provided so that one end of the wafer comes into contact with it. It is grounded at least while the wafer carrier is placed thereon.

Next, a case in which wafer carriers are stored using this wafer carrier holding device will be described with reference to FIG. 2. The figure shows a state in which the wafer carrier is already placed on the wafer carrier holding device.

In the same figure, the same reference numerals as those in FIG. 1 indicate the same parts as in FIG. is a Si wafer with a diameter of 4 inches loaded on a wafer carrier 4.

First, in order to remove the resist film and other organic substances remaining on the Si wafer 5, the wafer carrier 4 loaded with the Si wafer 5 is immersed in a mixed solution of 11°s04/11202, and then washed and dried. At this time, since the wafer carrier 4 is made of Teflon, it will not be exposed to the chemical solution. However, static electricity is induced in the wafer carrier 4 due to friction with the chemical solution, and the wafer carrier 4 becomes electrically charged. This charging voltage can be as high as about -10,000 V.

Therefore, the same amount of static electricity is induced in the Si wafer 5 as well.

Next, in order to store the Si wafer 5, the dried wafer carrier 4 is placed on the holding table 1 of the wafer carrier holding device in a storage box (not shown). At this time, one end of the lower portion of the Si wafer 5 comes into contact with the wafer contact portion 3 which has been grounded in advance. As a result, static electricity induced in the Si wafer 5 begins to escape to the ground electrode via this semiconductive wafer contact portion 3.

After leaving it in this state for 20 hours, it is taken out from the storage box for the next step.

Here, the size of the material attached to the surface of the Si wafer 5 is 0.2
When the number of dust particles larger than μm was measured using a dust detection device using laser light, the number of dust particles was about 10, which is equivalent to 1/10 of the conventional case. In this way, Si
The fact that the dust on the surface of the wafer 5 is significantly reduced indicates that
This shows that the static electricity on the wafer 5 has been sufficiently removed.

As described above, according to the wafer carrier holding device of the present invention, even if the material of the wafer carrier 4 is an insulating material that easily induces static electricity, static electricity induced on the Si wafer 5 can be prevented while the Si wafer 5 is being stored. Since it is possible to prevent the Si wafer 5 from being charged by removing it, the amount of dust adhering to the surface of the Si wafer 5 can be significantly reduced.

Thereby, the yield of semiconductor devices can be improved. In addition, since the wafer carrier can be made of chemically resistant material, it is possible to make the Si wafer 5
There is no need to transfer. Therefore, the generation of dust during transfer can be prevented, and the yield of semiconductor devices can be further improved.

[Effects of the Invention] As described above, according to the wafer carrier holding device of the present invention, even if the material of the wafer carrier is an insulating material that easily induces static electricity, static electricity induced in the wafer during storage of the wafer can be reduced. can be removed to prevent the wafer from becoming electrically charged.
Dust adhering to the wafer surface can be significantly reduced.

Thereby, the yield of semiconductor devices can be improved. Furthermore, since the wafer carrier can be made of a chemically resistant material, there is no need to transfer the wafer when processing it with a chemical solution. Therefore, the generation of dust during transfer can be prevented, and the yield of semiconductor devices can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view illustrating a wafer carrier holding device according to an embodiment of the present invention, and FIG. 2 is a perspective view illustrating a method of using the wafer carrier holding device according to an embodiment of the present invention. (Explanation of symbols) ■... Holding stand, 2... Guide, 3... Eva contact portion, 4... Wafer carrier, 5... Si wafer carrier

Claims (1)

[Claims] A wafer carrier holding device for mounting a wafer carrier, comprising a conductive or semiconductive wafer contact portion such that at least one end of a wafer in the wafer carrier comes into contact with the wafer carrier when the wafer carrier is mounted. A wafer carrier holding device comprising: