CN-113903699-B - Electrostatic chuck and semiconductor processing equipment

CN113903699BCN 113903699 BCN113903699 BCN 113903699BCN-113903699-B

Abstract

The invention provides an electrostatic chuck and semiconductor processing equipment, wherein an air passage structure comprises an annular air passage, a main air passage group and a secondary air passage group, wherein the annular air passage is positioned at the edge close to the upper surface of a chuck body and used for limiting a heat exchange area on the inner side of the annular air passage, the main air passage group surrounds a central air inlet hole, the secondary air passage group surrounds the main air passage group, the main air passage group is respectively communicated with the central air inlet hole and the secondary air passage group and is arranged to improve the speed of conveying back-blowing gas flowing out of the central air inlet hole to the secondary air passage group, and the secondary air passage group is respectively communicated with the main air passage group and the annular air passage and is arranged to enable the back-blowing gas to be uniformly distributed at different positions of the heat exchange area. The electrostatic chuck and the semiconductor processing equipment provided by the invention can effectively shorten the ventilation time of back-blowing gas on the premise of ensuring that the back-blowing gas pressure meets the requirements of stability and uniformity, thereby improving the productivity of the equipment.

Inventors

SHI QUANYU
YE HUA
YU BIN

Assignees

北京北方华创微电子装备有限公司
北京北方华创微电子装备有限公司

Dates

Publication Date: 20260421
Application Date: 20210922
Priority Date: 20210922

Claims (8)

1. An electrostatic chuck is applied to semiconductor processing equipment and comprises a chuck body, and is characterized in that the upper surface of the chuck body is provided with a central air inlet hole and an air channel structure; The air passage structure comprises an annular air passage, a main air passage group and a secondary air passage group, wherein the annular air passage is positioned at the edge of the upper surface of the chuck body and used for limiting a heat exchange area on the inner side of the chuck body; the main air passage group comprises a plurality of main air passages uniformly distributed around the circumference of the central air inlet hole, each main air passage is arranged along the radial direction of the central air inlet hole, the air inlet end of each main air passage is communicated with the central air inlet hole, and the air outlet end of each main air passage is communicated with the secondary air passage group; The secondary air passage group comprises a multi-stage sub air passage group which sequentially surrounds along the direction far away from the central air inlet hole, each stage of the sub air passage group comprises a plurality of secondary air passages, the air outlet end of each primary air passage is communicated with the air inlet ends of the plurality of secondary air passages in the adjacent stage of the sub air passage group, the plurality of secondary air passages communicated with the same primary air passage extend from the air outlet end of the primary air passage to different directions far away from the central air inlet hole, the air outlet end of each secondary air passage of the upstream stage is communicated with the air inlet ends of the plurality of secondary air passages of the adjacent downstream stage, the plurality of secondary air passages of the downstream stage communicated with the same secondary air passage of the upstream stage extend from the air outlet end of the secondary air passage of the upstream stage to different directions far away from the central air inlet hole, each secondary air passage of the sub air passage group adjacent to the annular air passage is converged into a public air outlet end, the public air outlet end is communicated with the annular air passage, and at least two other air passages not adjacent to the annular air passage are converged into the public air outlet end.
2. The electrostatic chuck of claim 1, wherein the secondary air channels have a width of 0.5mm or more and 3mm or less, a depth of 0.1mm or more and 0.4mm or less, and a number of 9 or more and 100 or less.
3. The electrostatic chuck of claim 1, wherein the secondary air passage group comprises two levels of the sub air passage groups, namely a first level air passage group and a second level air passage group, wherein the first level air passage group comprises a plurality of first secondary air passages, the air outlet end of each primary air passage is communicated with the air inlet ends of three primary air passages, and the air outlet ends of the two primary air passages are converged into a first common air outlet end with the air outlet ends of the adjacent primary air passages; The second-stage air passage group comprises a plurality of second air passages, wherein in three first air passages communicated with the same main air passage, the air outlet ends of the middle first air passages are communicated with the air inlet ends of two second air passages, each first public air outlet end is communicated with the air inlet ends of two second air passages, the air outlet ends of each second air passage and the adjacent air outlet ends of the second air passages are converged into a second public air outlet end, and the second public air outlet ends are communicated with the annular air passages.
4. The electrostatic chuck of claim 1 or 3, wherein said secondary air path set further comprises a plurality of transition air paths, wherein an air inlet end of each transition air path is in communication with each common air outlet end adjacent to said annular air path in a one-to-one correspondence, and an air outlet end of each transition air path is in communication with said annular air path.
5. The electrostatic chuck of any of claims 1-3, wherein the annular centerline of the annular air channel has a diameter of 270mm or more and 290mm or less, a radial width of the annular air channel is 0.5mm or more and 3mm or less, and a depth of the annular air channel is 0.1mm or more and 0.4mm or less.
6. The electrostatic chuck of claim 1, wherein the upper surface of the chuck body is further provided with a bump structure, the bump structure is located in a non-air channel region of the upper surface of the chuck body for carrying a wafer, and a preset distance is provided between a carrying surface of the bump structure and the upper surface of the chuck body; the bump structure comprises a plurality of bumps uniformly distributed in the non-air passage area, wherein the ratio of the total orthographic projection area of the bumps on the upper surface of the chuck body to the upper surface area of the chuck body is more than or equal to 2% and less than or equal to 10%.
7. The electrostatic chuck of claim 6, wherein the predetermined pitch is 2 μm or more and 10 μm or less.
8. A semiconductor processing apparatus comprising a process chamber and an electrostatic chuck disposed in the process chamber, wherein the electrostatic chuck employs the electrostatic chuck of any one of claims 1-7.

Description

Electrostatic chuck and semiconductor processing equipment Technical Field The invention relates to the field of semiconductor manufacturing, in particular to an electrostatic chuck and semiconductor processing equipment. Background The electrostatic chuck (Electrostatic Chuck, ESC) is used for carrying the wafer in an electrostatic adsorption manner, so as to avoid the movement or dislocation of the wafer in the process. In the process, back-blowing gas with certain pressure is introduced into a gap between the electrostatic chuck and the wafer to improve the heat transfer capability of the electrostatic chuck to the wafer, and avoid vacuum insulation, so that the control capability of the electrostatic chuck to the wafer temperature can be improved, and in addition, the electrostatic chuck can also provide radio frequency bias voltage for the wafer. The electrostatic chuck is typically placed in a vacuum chamber, for example a physical vapor deposition (Physical Vapor Deposition, PVD) apparatus, which is at a background vacuum (typically on the order of 10 -8 Torr or 10 -9 Torr) when the wafer is transferred into the vacuum chamber of the PVD apparatus and placed on the electrostatic chuck. At this time, the wafer and the electrostatic chuck are in a vacuum heat-insulating state, the electrostatic chuck cannot realize temperature control of the wafer, back-blowing gas needs to be introduced into a gap between the wafer and the electrostatic chuck and kept at a certain air pressure (for example, 1-20 Torr), and the back-blowing gas can perform heat transfer between the electrostatic chuck and the wafer so as to realize temperature control capability of the electrostatic chuck. The electrostatic chucks may be classified into a coulomb type electrostatic chuck, which operates on the principle that an electrostatic attraction force generated between an electrode and a wafer is used to adsorb the wafer, and a very back type electrostatic chuck, which operates on the principle that an electrostatic attraction force generated between an upper surface of the electrostatic chuck and the wafer is used to adsorb the wafer. In order to improve the heat transfer efficiency, an air channel is usually disposed on the upper surface of the electrostatic chuck, which is helpful for the back-blowing gas to diffuse to different positions of the wafer through the air channel, but the thickness of the dielectric layer above the electrode is thinner due to the fact that the electrode in the coulomb type electrostatic chuck is closer to the wafer, the air channel cannot be disposed, and the electrode in the J-R type electrostatic chuck is farther from the wafer, the dielectric layer above the electrode is thicker, and the air channel can be manufactured. However, for the J-R type electrostatic chuck, the existing air passage structure needs to be filled with back-blowing air for a long time (more than 100 s), so that the stability and uniformity of back-blowing air pressure can meet the process requirements, the PVD process can be started, the PVD process time is generally only in the range of 20-100s, the equipment productivity is low, and the PVD process cannot be applied to industrial production. Disclosure of Invention The invention aims to at least solve one of the technical problems in the prior art, and provides an electrostatic chuck and semiconductor processing equipment, which can effectively shorten the ventilation time of back-blowing gas on the premise of ensuring that the back-blowing gas pressure meets the requirements of stability and uniformity, thereby improving the productivity of the equipment. The invention provides an electrostatic chuck for semiconductor processing equipment, which comprises a chuck body, wherein the upper surface of the chuck body is provided with a bump structure, a central air inlet hole and an air channel structure, the bump structure is positioned in a non-air channel area of the upper surface of the chuck body and is used for bearing a wafer, and a preset distance is reserved between a bearing surface of the bump structure and the upper surface of the chuck body; The air passage structure comprises an annular air passage, a main air passage group and a secondary air passage group, wherein the annular air passage is positioned at the edge of the upper surface of the chuck body and used for limiting a heat exchange area on the inner side of the chuck body; the main air passage group is respectively communicated with the central air inlet hole and the secondary air passage group and is arranged to increase the speed of conveying back-blowing air flowing out of the central air inlet hole to the secondary air passage group; The secondary air passage group is respectively communicated with the main air passage group and the annular air passage, and is arranged so that the back-blowing air can be uniformly distributed at different positions of the heat exchange area. Optionally, the ratio o