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CN-114388384-B - Pre-vacuumizing chamber with wafer cleaning function and wafer cleaning method

CN114388384BCN 114388384 BCN114388384 BCN 114388384BCN-114388384-B

Abstract

The invention discloses a pre-vacuumizing chamber with a wafer cleaning function and a wafer cleaning method, belongs to the technical field of semiconductors, and solves the problems of low yield and process conversion alignment errors caused by the existence of particulate matters on the back of a wafer in the prior art. The pre-vacuumizing chamber comprises a chamber, a nozzle, a bracket and a vacuum chuck, wherein the bracket is arranged in the center of the chamber, the vacuum chuck is fixed at the top end of the bracket, the nozzle is arranged in the radial direction of a circle taking the vacuum chuck as the center of the circle, the vacuum chuck is used for fixing a wafer and driving the wafer to rotate, and the nozzle is arranged below the wafer. The invention is suitable for cleaning the back of the wafer.

Inventors

  • LI HUANGUI
  • ZHOU NA
  • LI LIN
  • WANG JIA
  • LI JUNJIE

Assignees

  • 中国科学院微电子研究所
  • 真芯(北京)半导体有限责任公司

Dates

Publication Date
20260512
Application Date
20201019

Claims (9)

  1. 1. The wafer cleaning method is characterized in that the following pre-vacuumizing chamber with a wafer cleaning function is used, wherein the pre-vacuumizing chamber comprises a chamber, a nozzle, a bracket and a vacuum chuck; The support is arranged in the center of the cavity, the vacuum chuck is fixed at the top end of the support, and the nozzle is arranged in the radial direction of a circle taking the vacuum chuck as the center of the circle; the vacuum chuck is used for fixing the wafer and driving the wafer to rotate, and the nozzle is arranged below the wafer; The bottom of the cavity is provided with an air extraction opening, the air extraction opening and the nozzle are positioned on the same side, and the air extraction opening is positioned below the nozzle; the nozzle is provided with micropores capable of uniformly blowing gas to the back of the wafer, the gas injection width formed by a plurality of rows of micropores is larger than or equal to the radius of the wafer, and the opening row number of the micropores is adjustable according to the size of the wafer; the distance between the nozzle and the back of the wafer is 1 10cm; The wafer cleaning method comprises the following steps: transferring the wafer into a pre-vacuumizing chamber, and fixing the wafer by adopting a vacuum chuck; In the atmospheric state, the vacuum chuck drives the wafer to rotate, and the nozzle blows gas to clean the back of the wafer when the air suction starts; after the pressure of the pre-vacuumizing chamber is pumped to 300mT, the blowing of gas is stopped, and the dropped fine foreign matters are discharged from the pumping line.
  2. 2. The method of claim 1, wherein a filter is disposed in an air inlet line of the nozzle.
  3. 3. The method of claim 1, wherein the chamber bottom is provided with an N 2 inlet, and the N 2 inlet is provided with a diffuser.
  4. 4. The method of claim 1, wherein the nozzle is provided with micro-holes that uniformly purge gas to the back of the wafer.
  5. 5. The method of claim 1, wherein the number of micropores is 1 to 10000, and the size of the micropores is 0.001mm to 50mm.
  6. 6. The method of claim 1, wherein the nozzle is one of a circular, triangular, tetragonal, pentagonal, hexagonal shaped tube.
  7. 7. The method of any of claims 1-6, wherein a nozzle holder is disposed below the nozzle.
  8. 8. The method of claim 1, wherein the rotational speed of the wafer is 10 to 1000 rpm.
  9. 9. The method of claim 1, wherein the flow rate of the gas blown from the nozzle is 1 to 50torr.

Description

Pre-vacuumizing chamber with wafer cleaning function and wafer cleaning method Technical Field The invention belongs to the technical field of semiconductors, and particularly relates to a pre-vacuumizing chamber with a wafer cleaning function and a wafer cleaning method. Background Wafer cleaning is generally classified into front side and back side cleaning. If particulate matter exists on the back of the wafer, the fine foreign matter can cause helium leakage fault on hardware of the etching process chamber during processing. The fine particles on the back of the wafer cause errors in equipment and plasma deformation in the 8-process of semiconductor fabrication, resulting in various problems such as process drift (CD, low yield, particles) and misalignment. The existing wafer back surface cleaning process is to clean the back surface by utilizing water in wet cleaning equipment so as to achieve the effect of cleaning particles on the back surface of the wafer. In the integrated circuit manufacturing process, the wet cleaning process steps of a plurality of wafers are included, and cleaning is needed before each etching process, so that the manufacturing time of the integrated circuit is greatly prolonged. Disclosure of Invention In view of the above analysis, the present invention aims to provide a pre-vacuum chamber with a wafer cleaning function and a wafer cleaning method, which are used for solving the problems of low yield, wafer transfer alignment error and the like caused by particulate matters on the back of a wafer in the prior art. The aim of the invention is mainly realized by the following technical scheme: A pre-vacuumizing chamber with a wafer cleaning function comprises a chamber, a nozzle, a bracket and a vacuum chuck; The vacuum chuck is used for fixing the wafer and driving the wafer to rotate, and the nozzle is arranged below the wafer. In one possible design, a filter is provided in the air inlet line of the nozzle. In one possible design, the bottom of the chamber is provided with an N 2 inlet and a pumping port, and the N 2 inlet is provided with a diffuser. In one possible design, the nozzles are provided with micro holes that can uniformly purge gas to the back of the wafer. In one possible design, the number of micropores is 1 to 10000, and the size of micropores is 0.001mm to 50mm. In one possible design, the nozzle is one of a circular, triangular, tetragonal, pentagonal, hexagonal shaped tube. In one possible design, a nozzle holder is provided below the nozzle. A method of cleaning a wafer, comprising the steps of: transferring the wafer into a pre-vacuumizing chamber, and fixing the wafer by adopting a vacuum chuck; In the atmospheric state, the vacuum chuck drives the wafer to rotate, and the nozzle blows gas to clean the back of the wafer when the air suction starts; after the pressure of the pre-vacuumizing chamber is pumped to 300mT, the blowing of gas is stopped, and the dropped fine foreign matters are discharged from the pumping line. In one possible design, the wafer may rotate at 10 to 1000rpm. In one possible design, the flow rate of the nozzle purge gas is 1 to 50Torr. Compared with the prior art, the invention can at least realize one of the following technical effects: 1) In the pre-vacuumizing chamber, a wafer is fixed by a vacuum chuck, and gas (such as N 2) is blown on the surface of the wafer in a rotating state to remove foreign matters, so that the problems of CD, low yield, particles and the like caused by errors generated by fine particles or process drift caused by plasma deformation are solved. And equipment back He leakage caused by fine particles on the back is improved (shutdown loss is reduced and productivity is improved). 2) The back cleaning device is arranged in the pre-vacuumizing chamber, so that the back cleaning of the wafer in the pre-etching process (wet etching) can be skipped, the wafer cleaning is required before each etching process in the integrated circuit manufacturing process is avoided, and the manufacturing time and the working procedures of the integrated circuit are greatly saved. 3) The nozzle arranged below the wafer has a micropore structure, and can uniformly purge gas to the back of the wafer through micropores, so that foreign matters can be effectively removed. 4) The filter is arranged on the air inlet pipeline of the nozzle, so that the introduction of foreign matters can be avoided. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and drawings. Drawings The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, like numbers referring to like parts t