KR-20260066260-A - Wafer Edge Contact Grounding Device and Method

KR20260066260AKR 20260066260 AKR20260066260 AKR 20260066260AKR-20260066260-A

Abstract

The present invention relates to a wafer edge contact grounding device and method for effectively removing electric charge accumulated on a wafer, and more specifically, when a wafer descends onto the wafer chuck surface, the edge portion of the wafer contacts the grounding spring portion, thereby allowing electric charge to flow to the connected circuit portion through this, so as to uniformly remove the electric charge remaining on the wafer. According to the present invention, the wafer edge contact ground device (G) includes a ground spring part (20) and a circuit part (30).

Inventors

유형욱
김일광
임은재

Assignees

주식회사 코비스테크놀로지

Dates

Publication Date: 20260512
Application Date: 20241104

Claims (13)

In a wafer edge contact ground device for removing electric charge from a wafer, A ground spring portion that contacts the edge of the wafer when the wafer descends into the wafer chuck; and A circuit part connected to the ground spring part and transferring the charge of the wafer; A wafer edge contact ground device including
In paragraph 1, An actuator that moves the above ground spring portion horizontally, vertically, or rotationally; A wafer edge contact ground device further comprising
In paragraph 1, A wafer edge contact ground device characterized in that the wafer chuck is an electrostatic chuck or a vacuum chuck with an anti-static coating.
In paragraph 1, The above grounding spring part is, Placed in the internal space of the wafer chuck above, and A fixing bolt for fixing the ground spring portion to the wafer chuck; and A fixing washer located between the grounding spring portion and the fixing bolt; A wafer edge contact ground device characterized by including
In paragraph 2, The above grounding spring part is, It is positioned at the top of the above actuator, and A fixing bolt for fixing the above ground spring portion to the top of the actuator; and A fixing washer located between the grounding spring portion and the fixing bolt; A wafer edge contact ground device characterized by including
In paragraph 1, The above ground spring part is any one of an elastic leaf spring, a cam pivot type spring, or a pogo pin, and A wafer edge contact ground device characterized by the force of the ground spring part being set to a minimum elasticity.
In paragraph 1, A wafer edge contact ground device characterized by the ground spring portion being disposed in one or more places on the wafer chuck.
In paragraph 1 or 2, The above circuit section is, A wafer edge contact ground device characterized by penetrating the wafer chuck or the actuator or being directly connected to the ground spring portion.
In a method for relieving residual charge on a wafer using a wafer edge contact ground device, A step of supplying a wafer to the upper part of a wafer chuck using a wafer transfer robot; A step in which the wafer is lowered to the surface of the wafer chuck by the wafer transfer robot; A step in which the edge of the wafer contacts a ground spring portion; and A step of electrically connecting the wafer and the ground spring portion; A method for relieving residual charge on a wafer including
In Paragraph 9, After the wafer descends onto the surface of the wafer chuck, the actuator connected to the ground spring unit approaches the wafer chuck; A wafer residual charge removal method further comprising
In Paragraph 10, A method for relieving residual charge on a wafer, characterized in that the actuator is one of a horizontal actuator, a vertical actuator, or a rotary actuator.
In Paragraph 9, The above grounding spring part is, Placed in the internal space of the wafer chuck above, and A fixing bolt for securing the grounding spring to the wafer chuck; and A fixing washer located between the grounding spring and the fixing bolt; A method for relieving residual charge on a wafer, characterized by including
In Paragraph 10, The above grounding spring part is, It is positioned at the top of the above actuator, and A fixing bolt for fixing the grounding spring to the top of the actuator; and A fixing washer located between the grounding spring and the fixing bolt; A method for relieving residual charge on a wafer, characterized by including

Description

Wafer Edge Contact Grounding Device and Method The present invention relates to a wafer edge contact grounding device and method for effectively removing electric charge accumulated on a wafer, and more specifically, when a wafer descends onto the wafer chuck surface, the edge of the wafer contacts a grounding spring portion, thereby allowing electric charge to flow to a connected circuit portion through this, so as to uniformly remove the electric charge remaining on the wafer. A wafer chuck is a device that fixes the bottom of a wafer to maintain its stable position during various manufacturing and inspection processes, and is primarily used in semiconductor and display inspection equipment. Wafer chucks operate by securing the wafer through vacuum pressure or electrostatic force, and can be implemented in various forms, such as vacuum chucks or electrostatic chucks, depending on the process. In semiconductor and display manufacturing and inspection processes, electric charges may accumulate on wafers as they move through each stage due to equipment, manufacturing lines, and various process materials. If charges accumulate on the wafer, it can lead to equipment damage or data errors during precise inspection and measurement processes. In particular, the accumulation of electric charge on the wafer surface can lead to quality degradation, reduced production yield, and instability of measurement data. For example, static electricity can cause problems by adhering airborne contaminants to the wafer surface, which damages fine circuit patterns or alters device characteristics. Additionally, static electricity can cause patterns to be distorted or incompletely formed during etching and deposition processes, and during the doping process, non-uniform doping distribution can cause changes in the electrical characteristics of the device or generate unnecessary energy levels, posing a risk of device performance degradation. Existing methods for removing static electricity include creating a cleanroom environment, grounding workers, neutralizing static electricity using ionizing air generators, and using equipment contact devices with anti-static (ESD) coatings. However, vacuum chucks have limitations in dispelling static electricity on wafers because they are coated with ESD to prevent electrical conductivity. Consequently, it is common practice to dissipate static electricity using a separate ionized air device or grounding method before the wafer is placed in the vacuum chuck. Nevertheless, this process increases processing time, and the problem of recurring static electricity caused by contact with wafer transfer robots or friction with the atmosphere still persists. In addition, while there is a method of grounding by contacting a grounding pin to the bottom of the wafer, this carries the risk of damaging specific patterns or coating layers formed on the underside of the wafer during the process. Therefore, there is a need to develop wafer charge dissipation devices and methods to solve these problems. The technology regarding a method, apparatus, and system for wafer grounding, which forms the background of the present invention, is described in Korean Registered Patent No. 10-2704793 (published September 11, 2024). FIG. 1 is a drawing for explaining a wafer edge contact ground device according to one embodiment of the present invention. FIG. 2 is a drawing for explaining the horizontal movement of a wafer edge contact ground device according to one embodiment of the present invention. FIG. 3 is a diagram illustrating the vertical movement of a wafer edge contact ground device according to one embodiment of the present invention. FIG. 4 is a diagram illustrating the rotational movement of a wafer edge contact ground device according to one embodiment of the present invention. FIG. 5 is a drawing showing a plurality of wafer edge contact ground devices according to one embodiment of the present invention installed on a wafer chuck. FIG. 6 is a flowchart illustrating a method for relieving residual charge on a wafer using a wafer edge contact ground device according to an embodiment of the present invention. FIG. 7 is a drawing for illustrating a wafer edge contact ground device according to another embodiment of the present invention. The present invention is capable of various modifications and may take various forms, and embodiments (aspects or examples) are to be described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed forms, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. The terms used in this specification are used merely to describe specific embodiments (aspects or examples) and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms