CN-122003124-A - Electrostatic chuck base and welding method thereof

CN122003124ACN 122003124 ACN122003124 ACN 122003124ACN-122003124-A

Abstract

The invention discloses an electrostatic chuck base and a welding method thereof, wherein the electrostatic chuck base comprises a base body, a welding plate and a welding plate, wherein the base body is provided with a cavity with an upward opening, a vortex-shaped guide plate is arranged at the bottom of the cavity, a vortex-shaped cooling groove is formed between the guide plate and the cavity, and the upper end surface of the guide plate is provided with a welding plate groove extending along the length direction of the guide plate; the brazing welding lug is arranged in the welding lug groove, the thickness of the brazing welding lug is the same as the groove depth of the welding lug groove, the brazing welding lug heats and melts, and the melted brazing welding lug fills the gap through capillary action. This scheme improves the joint strength of apron on the base body, prevents that the base from welding the problem that the apron perk caused cooling runner cluster liquid in the base in the heating process of welding, and the apron swell influences the base roughness under the long-term pressurized condition of cooling runner.

Inventors

ZHENG SHENGHUA
XIE RUYING
ZHOU ZIJUN
WANG HONGJUN
XU HUAJIAN

Assignees

浙江先导精密机械有限公司

Dates

Publication Date: 20260508
Application Date: 20251231

Claims (10)

1. An electrostatic chuck base, comprising: the base body is provided with a cavity with an upward opening, the bottom of the cavity is provided with a vortex-shaped guide plate, a vortex-shaped cooling groove is formed between the guide plate and the cavity, and the upper end surface of the guide plate is provided with a soldering lug groove extending along the length direction of the guide plate; The cover plate cover is arranged on the guide plate and forms a cooling flow passage with the cooling groove, and a gap is arranged between the upper end face of the guide plate positioned at the inner side of the soldering lug groove and the cover plate; The brazing welding lug is arranged in the welding lug groove, the thickness of the brazing welding lug is the same as the groove depth of the welding lug groove, the brazing welding lug is heated and melted, and the melted brazing welding lug fills the gap through capillary action.
2. An electrostatic chuck base according to claim 1, wherein the base body is provided with an inlet and an outlet, the inlet communicates with one end of the cooling tank and a lower end surface of the base body, and the outlet communicates with the other end of the cooling tank and a lower end surface of the base body.
3. An electrostatic chuck base according to claim 2, wherein the bottom of the lug well is provided with a fine hole communicating the lug well with the lower end surface of the base body.
4. An electrostatic chuck base according to claim 3, wherein said plurality of holes is a plurality of holes distributed along the length of said tab slot.
5. An electrostatic chuck base according to claim 1 or 2 or 3 or 4, wherein the upper end surface of the cover plate is flush with the upper end surface of the base body, and the peripheral wall of the cover plate engages the inner side wall of the base body.
6. An electrostatic chuck base according to claim 1 or 2 or 3 or 4 wherein said brazing tab mates with said tab slot, said brazing tab extending along the length of said guide plate.
7. A method of welding an electrostatic chuck base according to any one of claims 1 to 6, comprising the steps of, in order: step 1, sequentially installing a base body, a brazing welding lug and a cover plate before welding; step 2, welding the lower end surface of the cover plate with the base body through vacuum brazing; and 3, welding the peripheral wall of the cover plate with the base body through electron beam welding.
8. The welding method of the electrostatic chuck base according to claim 7, wherein in the step 2, the installed base is clamped and placed in a brazing furnace, the furnace is vacuumized to 5x10 < -3 > pa after the door is closed, the temperature is kept for 10min after the first 60min is raised to 360 degrees, the temperature is kept for 10min after the first 30min is raised to 550 degrees, the temperature is kept for 70min after the second 20min is raised to 570 degrees, the temperature is kept for 20min after the temperature is raised to 590 degrees, the pressure is released after the last 60min is lowered to 60 degrees or less, the vacuum brazing is completed after the pressure is released, and the base is taken out.
9. The welding method of the electrostatic chuck base according to claim 7, wherein in the step 3, the base is fixed on a vacuum electron beam welding workbench, a door is closed after a working distance is determined, a vacuum chamber is vacuumized to 5x10 < -5 > mbar, spot welding penetration is sequentially conducted for 1mm, sealing welding penetration is 2mm, formal welding penetration is 9mm, finishing welding penetration is 2.5mm, a vacuum chamber is opened after pressure relief, and the base is taken out after welding is checked.
10. The method of claim 7, wherein the step 1 is preceded by chemically cleaning the base body and the cover plate to be welded and packaging, and the packaging is opened and installed before the base is welded.

Description

Electrostatic chuck base and welding method thereof Technical Field The invention relates to the technical field of semiconductor device manufacturing, in particular to an electrostatic chuck base and a welding method thereof. Background The electrostatic chuck is an ultra-clean wafer carrier suitable for vacuum and plasma working conditions, utilizes the electrostatic adsorption principle to carry out flat and uniform clamping of an ultra-thin wafer, has the key effects of adsorbing silicon wafers, glass and various mask objects, and ensures that the silicon wafers, the glass and various mask objects maintain excellent flatness in the process, thereby effectively inhibiting deformation. The electrostatic chuck is typically composed of three core components, an insulating layer, a heater, and a susceptor. The pedestal is one of the main core components, and its performance quality directly affects the performance quality of the whole electrostatic chuck. At present, the manufacturing technology of the domestic electrostatic chuck base is not stable enough (liquid flowing among channels exists in the welding process of the base cooling channels), and particularly, the problem of liquid flowing among channels is difficult to solve by the traditional welding process aiming at the large-size base. With the development of new generation semiconductor technology, the processes such as low temperature etching and deposition generally require the wafer to reach a lower temperature, so that a higher requirement is put on the heat dissipation performance of the electrostatic chuck, and the problem of unstable welding process of the cooling flow channel of the base is solved to improve the cooling and heat dissipation performance. The welding of the existing electrostatic chuck base welds the peripheral wall of the cover plate and the base body through electron beam welding or friction stir welding, and the large-size base generates a larger gap with the base body after the cover plate is tilted due to thermal deformation in the welding process, so that the cooling flow channel is in fluid connection, and the cover plate is thinner because of no welding between the lower end surface of the cover plate and the base body, so that the cover plate is easy to bulge outwards under the condition that the cooling flow channel is pressed for a long time, and the problems of poor flatness of the base and the cooling flow channel are caused. For example, chinese patent publication No. CN118588624a, publication No. 2024, year 09 and month 03, entitled "a dual-function electrostatic chuck base for cooling and heating", includes a base body in which a cooling flow channel is provided, and a plurality of heating elements are mounted on the base body. The existing patent has the defects that the welding of the existing electrostatic chuck base welds the peripheral wall of the cover plate with the base body through electron beam welding or friction stir welding, the large-size base generates larger gaps between the cover plate and the base body after the cover plate is tilted due to thermal deformation in the welding process, so that liquid is mixed in the cooling flow channel, and part of the cover plate is thinner due to the fact that the lower end face of the cover plate is not welded with the base body, the cover plate is easy to bulge outwards under the condition that the cooling flow channel is pressed for a long time, and the problems of liquid mixing of the cooling flow channel of the base and poor flatness of the base are caused. Disclosure of Invention The invention aims to solve the problems of poor flatness and liquid stringing of a base cooling flow passage caused by welding heated deformation and long-term compression of the cooling flow passage in the base of a large size base under the conditions that the outer peripheral wall of a cover plate is welded with a base body through electron beam welding or friction stir welding in the welding of the existing electrostatic chuck base, and provides an electrostatic chuck base and a welding method thereof. In order to achieve the above purpose, the present invention adopts the following technical scheme: an electrostatic chuck base comprising: the base body is provided with a cavity with an upward opening, the bottom of the cavity is provided with a vortex-shaped guide plate, a vortex-shaped cooling groove is formed between the guide plate and the cavity, and the upper end surface of the guide plate is provided with a soldering lug groove extending along the length direction of the guide plate; The cover plate cover is arranged on the guide plate and forms a cooling flow passage with the cooling groove, and a gap is arranged between the upper end face of the guide plate positioned at the inner side of the soldering lug groove and the cover plate; The brazing welding lug is arranged in the welding lug groove, the thickness of the brazing welding lug is the same as the groove d