Cleaning method used in amorphous carbon deposition process

Abstract

The invention relates to a cleaning method used in an amorphous carbon deposition process. The cleaning method comprises a process step S1 of pre-cleaning a plasma chamber body under a plasma condition and a process step S2 of depositing an environment protecting film on the plasma chamber body; the step S2 particularly comprises the steps of introducing gas containing C2H2, Ar and He into the plasma chamber body, depositing a layer of non-N-doped amorphous carbon film having a first thickness on the plasma chamber body wall, then introducing gas containing C2H2 and N2 into the plasma chamber body, again growing a layer of N-doped amorphous carbon film having a second thickness on the non-N-doped amorphous carbon film, wherein the second thickness is less than the first thickness. Therefore, the problems of wafer backside aluminum pollution and caused easy migration of a wafer position are avoided.

Description

technical field [0001] The invention relates to the technical field of integrated circuit manufacturing, and more specifically relates to a cleaning method using plasma enhanced chemical vapor deposition (Plasma Enhanced Chemical Vapor Deposition, referred to as PECVD) in an amorphous carbon film deposition process. Background technique [0002] Usually, before using chemical vapor deposition equipment to deposit thin films on silicon wafers, the cavity needs to be pre-cleaned to remove the deposited film accumulated in the cavity and the particles suspended in the cavity. In the cleaning process, first of all, it is necessary to pass cleaning gas into the cavity, such as NF 3 . Gas NF 3 In the plasma environment, fluorine ions are ionized and react with the chamber wall and the deposited film on the heater (Heater) to generate fluorine-containing gas, which is pumped away to clean the chamber. [0003] For deposition machines including amorphous carbon film (APF for shor...

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Problems solved by technology

[0013] To sum up, the above two existing technologies have aluminum contamination on the back of the wafer and the problem that the position of the wafer is easily shifted

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