KR20000032024A - Insulating ring of electrostatic chuck for dry etching device - Google Patents

Abstract

PURPOSE: An insulating ring of an electrostatic chuck is provided to prevent an omission of a polymer by equaling a thermal expansion coefficient in every part of a body, to reduce processing numbers at an assembling and disassembling, and to minimize a damage by fragile property generated at a management after disassembling. CONSTITUTION: An insulating ring(700) is molded in a circular body to be installed by shielding an external circumference of an electrostatic chuck(15) placed a wafer inside a chamber using a ceramic of single material. The ceramic material formed the insulating ring(700) has the high thermal conductivity, cuts the heat generated by a plasma reaction inside the chamber directly into the electrostatic chuck(15), and conducts the heat into the electrostatic chuck(15) with a thermal gradient. Because the whole body of the insulating ring(700) is formed with the single material having the same thermal conductivity, a uniform etching of the wafer is performed by equaling the heat distribution of the electrostatic chuck(15). The standard of the insulating ring(700) is a 280mm, a 231mm inner diameter, a 41mm thickness of longest distance, and a 14mm thickness of shortest distance.

Description

Electrostatic Chuck Insulation Ring of Dry Etching Equipment

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic chuck insulating ring of a dry etching apparatus, and more particularly, to an electrostatic chuck insulating ring of a dry etching apparatus, which is mounted around an electrostatic chuck provided inside a chamber to protect an electrostatic chuck from plasma and block heat transfer to the electrostatic chuck. It is about.

Generally, in the pattern formation of a semiconductor wafer, in order to perform highly accurate etching with high integration and refinement | miniaturization of an element, the dry etching apparatus which performs etching by the plasma by a pair of parallel plate type electrode is used.

Referring to FIG. 1, which shows an example of a chamber structure used in a dry etching apparatus, the dry etching apparatus includes an upper electrode 14 for applying a high frequency power source RF to a chamber 10 inside which a high vacuum can be maintained. The lower electrode 15, the gas inlet 12 for the inlet of the compound mixed gas, and the outlet 13 for the discharge of the reaction gas, the thin film of the wafer WF placed on the lower electrode 15 to the gas plasma It is an apparatus for removing in accordance with the pattern of the photoresist film by etching.

FIG. 2 is an enlarged detailed view of the periphery of the lower electrode 15 shown in FIG. 1, wherein an electrostatic chuck (ESC) used as the lower electrode 15 is formed in a cylindrical flat plate to form a wafer ( WF) is fixed, and a cooling water passage is formed inside.

The insulating ring 70 handled in the present invention is mounted to surround the side surface of the electrostatic chuck 15, and has a structure in which a focus ring 16 for holding the position of the wafer WF is placed thereon. This structure is also applied to the UNITY 85DD facility of TEL (TOKYO ELECTRONIC LTD).

The insulating ring 70 protects the electrostatic chuck 15 from plasma and blocks heat generated during etching, and periodically removes by-products such as polymers generated in the etching process in the process management of the process. It is disassembled and assembled in the washing process performed by the.

By the way, the conventional insulating ring 70 is composed of the upper ring 72, the middle ring 74, the lower ring 76 to be matched to each other, the upper ring 72 and the lower ring 76 on the material Ceramic, the intermediate ring 74 is made of quartz.

As described above, since the conventional insulating ring 70 is composed of three parts having different materials, the upper ring 72, the middle ring 74, and the lower ring 76, the insulating ring 70 is disassembled and assembled. It takes a lot of work, and all three bodies (72, 74, 74) constituting the insulating ring (70) during the storage and storage after use, the brittle damage occurs and shakes during reassembly Since a gap is caused, it is difficult to achieve even etching of the wafer WF.

On the other hand, it is normal that the by-product polymer generated during etching adheres to the insulating ring 70, but the conventional insulating ring 70 is due to different materials between the connecting rings 72-74 and 74-76. Due to the difference in thermal conductivity, the degree of thermal expansion is different so that the polymer to stick to the joints between the rings 72-74 and 74-76 is likely to fall off. The polymer dropped out of the junction portion acts as a foreign material and adheres to the wafer WF, causing the wafer to be defective.

Accordingly, the present invention, in view of the above-described problems, the same thermal expansion rate in all parts of the insulating ring body to prevent the polymer from falling off, reduce the number of work during disassembly and assembly, brittleness occurs during management after decomposition An object of the present invention is to provide an electrostatic chuck insulating ring of a dry etching apparatus capable of minimizing damage by the same.

In order to achieve the above object, the present invention is provided in the chamber and mounted on the outer circumferential surface of the electrostatic chuck on which the wafer is placed, the electrostatic chuck insulation ring of the dry etching apparatus that protects the electrostatic chuck from plasma and blocks heat transfer to the electrostatic chuck. An electrostatic chuck insulating ring of a dry etching apparatus, wherein the annular body is formed so as to surround an outer circumferential surface of the electrostatic chuck at the time of mounting.

The present invention configured as described above can protect the electrostatic chuck from the plasma and block heat transfer to the electrostatic chuck as in the prior art, as well as prevent the defect of the wafer by the polymer dropped from the insulating ring to the maximum. It can minimize the work maneuver and minimize the damage caused by brittleness during management after disassembly.

1 is a schematic view of a typical dry etching apparatus

FIG. 2 is an enlarged detailed view of the periphery of the lower electrode illustrated in FIG. 1; FIG.

Figure 3 is a mounting state cross-sectional view showing the structure of the insulating ring according to the present invention

Explanation of symbols on the main parts of the drawings

10-chamber 12-gas inlet

13-outlet 14-upper electrode

15-electrostatic chuck (lower electrode) WF-wafer

16-Focus Ring 72-Top Ring

74-middle ring 76-lower ring

700-insulation ring

Figure 3 is a cross-sectional view showing the structure of the insulating ring according to the present invention, with reference to this will be described in detail a preferred embodiment of the present invention.

For reference, since the present invention is applied to the dry etching apparatus of FIG. 1 described in the prior art, reference numerals except for the insulating ring 700 will be given the same for the sake of clarity and to avoid overlapping descriptions.

Referring to FIG. 3, the insulating ring 700 of the present invention has an annular body to be mounted to surround the outer circumferential surface of the electrostatic chuck 15 on which the wafer WF in the chamber 10 is mounted using a single ceramic material. Molded. This does not separately form the upper ring 72, the middle ring 74 and the lower ring 76 constituting the conventional insulating ring 70, corresponding to the state in which the rings (72, 74, 76) assembled It is molded into one body in shape.

The material of the ceramic forming the insulating ring 700 is high in thermal conductivity, and prevents heat generated by the plasma reaction inside the chamber 10 from being directly transferred to the electrostatic chuck 15 and at a suitable temperature. It conducts to the electrostatic chuck 15 as a gradient. At this time, since the entire body of the insulating ring 700 is formed of a single material having the same thermal conductivity, the temperature distribution of the electrostatic chuck 15 is uniform, thereby realizing uniform etching of the wafer WF.

The diameter of the insulating ring 700 is 280mm outer diameter (Ro), inner diameter (Ri) is 231mm, longest distance thickness (Dg) is 41mm, shortest distance thickness (Ds) is 14mm. Ri, Ro Ds, Dg

The shortest distance thickness Ds is equal to the thickness of the conventional upper ring 72, and the longest distance thickness Dg includes the intermediate ring 74 from the conventional upper ring 72 and the lower ring 76. It is equal to the thickness leading to.

The insulating ring 700 of the present invention configured as described above is mounted by seating the inner circumferential surface of the insulating ring 700 made of one body on the outer circumferential surface of the electrostatic chuck 15 formed of a cylindrical flat plate. Therefore, the present invention can reduce the labor required for mounting compared to when the three bodies (72, 74, 76) separately mounted like the conventional insulating ring (70).

In addition, according to the present invention, since all of the body of the insulating ring 700 is formed of a single material of ceramic, thermal expansion coefficients of all parts of the body become the same, thereby preventing the dropping of the polymer due to the difference in thermal conductivity as in the prior art. Can be.

On the other hand, as shown in the present invention, if the insulating ring 700 is formed of one body, there is a fear that the electrical parameters will be predicted to be changed as compared to the conventional one formed by the assembly of the three bodies (72, 74, 76). However, experiments conducted by the Applicant confirmed that almost the same electrical parameters as in the prior art appear. That is, since the electrical parameters are almost the same, good dry etching can be performed without changing the gas mixing ratio, vacuum degree, temperature, high frequency power, and the like formed in the chamber 10.

As described above, the electrostatic chuck insulation ring of the dry etching apparatus of the present invention has the same thermal expansion rate at all parts of the body, thereby preventing foreign substances from adhering to the wafer by preventing the polymer from falling off when the thermal expansion rate is different, thereby increasing the yield. It is possible to improve the productivity by reducing the number of operations required during disassembly and assembly, and to increase the productivity by securing more equipment uptime. There is an effect that can improve the yield by preventing uneven etching of the wafer due to the gap play at the time.

On the other hand, the present invention is not limited to the specific preferred embodiment, it is a matter of course that a variety of applications are possible by ordinary knowledge in the art within the technical rights described in the claims.

Claims (1)

An electrostatic chuck insulation ring of a dry etching apparatus, which is provided in a chamber and mounted on an outer circumferential surface of an electrostatic chuck on which a wafer is placed, and which protects the electrostatic chuck from plasma and blocks heat transfer to the electrostatic chuck. An annular body to surround the electrostatic chuck insulation ring of a dry etching apparatus, characterized in that molded from a single material of ceramic.