Pre-deposition method for forming protection film in chamber

Abstract

The invention discloses a method for predepositing a protective film formed on the inner wall of a cavity, and relates to a slit filling processing procedure by pure hydrogen HDP-CVD process. A protective film formed by the prior predeposition method is easily separated in a subsequent processing procedure. The method comprises the following steps: first, introducing reaction gas in the cavity; then, opening top radio frequency and side radio frequency of the cavity to carry out a predeposition step to form the protective film on the inner wall of the cavity, wherein the predeposition step iscarried out in two steps: in one step, power of the top radio frequency is more that that of the side radio frequency; and in the other step, the power of the top radio frequency is less than that ofthe side radio frequency. Compared with the prior art, the protective film formed by the predeposition method has the advantages of even distribution and good adherence, so that in the subsequent pure hydrogen HDP-CVD process, the protective film can not be easily separated by plasma in fierce motion, thereby particle deficiency on the surface of a wafer is reduced in the processing procedure of filling a slit.

Description

technical field [0001] The invention relates to a shallow trench (STI) filling process using a pure hydrogen high-density plasma chemical vapor deposition (HDP-CVD) process, in particular to a pre-deposition method in the shallow trench filling process, which can be used in a cavity The inner wall forms a protective film. Background technique [0002] Due to its better filling capability, the pure hydrogen HDP-CVD process has become the mainstream process for filling shallow trenches in the technology generation of 90nm and below. In the pure hydrogen HDP-CVD filling shallow trench process, the temperature in the chamber (chamber) can generally reach about 800°, and the plasma activity is relatively intense. Therefore, the stability of the wafer surface characteristics becomes a key factor affecting the yield of the wafer. . [0003] Due to the intense activity of the plasma in the pure hydrogen HDP-CVD process, in order to avoid damage to the inner wall of the cavity by t...

AI Technical Summary

Problems solved by technology

However, in the actual manufacturing process, it is found that the protective film formed on the inner wall of the cavity is unevenly formed under the action of high-power radio frequency by using the existing technology, and some places are thick, and some places are thin, resulting in adhesion to the inner wall of the cavity. Not solid

In the pure hydrogen HDP-CVD process, the unevenly distributed protective film is easily peeled off by the violent collision of the plasma, resulting in particle defects on the wafer surface

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