Automatic determination method of the cleaning course end for the reaction boiler tube

Abstract

The reaction furnace tube cleaning procedure with automatically determined terminal suitable for low pressure chemical vapor deposition apparatus includes the following steps: leading cleaning gas into the reaction furnace tube to produce chemical reaction at specific temperature; continuously measuring the temperatures in several locations inside the reaction furnace tube; monitoring one of the temperatures until the temperature change converges to within some deflection value; monitoring all the temperatures until the temperature changes converge to within some deflection values; and over etching for one time period before stopping the reaction furnace tube cleaning procedure.

Description

technical field [0001] The invention relates to a cleaning process of a reaction furnace tube, and in particular to a method for automatically determining the end point of the cleaning process of the reaction furnace tube. Background technique [0002] Chemical vapor deposition (Chemical Vapor Deposition, CVD) is currently the most important thin film deposition method in the semiconductor process. According to the pressure of chemical vapor deposition, the chemical vapor deposition method can be divided into two types: atmospheric pressure chemical vapor deposition (APCVD) and low pressure chemical vapor deposition (LPCVD). Since the low-pressure chemical vapor deposition method deposits thin films at a pressure lower than 100 Torr (Torr), the formed thin films have excellent step coverage, and are currently widely used as a deposition method. method. [0003] In the semiconductor process, the thin film materials deposited by low pressure chemical vapor deposition mainly ...

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Problems solved by technology

[0005] However, setting the time required for dry cleaning in an artificially predictable manner creates problems

If the dry cleaning time is too long, the cleaning gas will corrode the inner wall of the reaction chamber and damage the quartz components in the reaction chamber, which will affect the service life of the entire low-pressure chemical vapor deposition machine

If the dry cleaning time is too short, the deposits on the inner wall of the reaction chamber cannot be completely removed, so when the next batch of chips is deposited, it will cause chip contamination

Moreover, if the sediment on the inner wall of the reaction chamber is not completely removed, another dry cleaning is required, which will increase the frequency of preventive maintenance (PM), reduce the uptime of the machine, and increase maintenance costs

[0006] In addition, since different film materials are deposited, the time required to clean the machine is also different, so it is necessary to find out the dry cleaning time suitable for each film deposition by trial and error method, but this This approach will consume a lot of manpower and time costs

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