SiC Susceptor Cleaning Endpoint Control via Mass Feedback
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Solution Overview
Problem
The existing semiconductor substrate manufacturing processes face challenges in accurately determining the end point of cleaning for SiC film deposition on susceptors, leading to inefficient cleaning and potential damage to the susceptor, which affects the yield and quality of epitaxial growth.
Innovation Solution
A semiconductor substrate manufacturing apparatus is designed with a film-forming chamber, a cleaning chamber for removing SiC films from susceptors using ClF3 gas, and a regeneration chamber for re-coating the susceptor, allowing for concurrent cleaning and film formation, and utilizing a chlorine gas detector to determine the end of cleaning treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cleaning is performed for a longer time to ensure complete removal of SiC film, then cleaning reliability is improved, but manufacturing time is wasted and susceptor damage risk increases
Solution Approach 1:
The patent implements feedback control by monitoring the mass change of the susceptor during cleaning using a balance. The cleaning process is dynamically adjusted based on real-time mass change data, allowing the system to automatically terminate cleaning when the SiC film is completely removed, thus avoiding unnecessary cleaning time and potential susceptor damage while ensuring complete film removal.
2Ease of manufacture
If cleaning is controlled by fixed etching time based on film thickness, then process simplicity is maintained, but cleaning precision deteriorates
Solution Approach 1:
The system replaces fixed-time control with real-time feedback control based on mass change monitoring. The balance continuously measures the susceptor mass during cleaning, and the control unit adjusts the cleaning process accordingly, achieving precise cleaning termination without complex manual calculations or fixed parameters.
Solution Approach 2:
The patent replaces the conventional mechanical/time-based control system with a measurement-based control system using mass detection. This substitution enables more precise control of the cleaning endpoint by using physical measurement data rather than predetermined time parameters.
3Reliability
If multiple chambers are used for film formation and cleaning, then process interference is avoided, but device complexity increases
Solution Approach 1:
The patent divides the manufacturing apparatus into functionally independent chambers: a film formation chamber for growing SiC films on wafers and a separate cleaning chamber for removing deposited films from susceptors. This segmentation allows each chamber to be optimized for its specific function and prevents process interference while maintaining overall system efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the efficiency of film formation by eliminating unnecessary cleaning, preventing susceptor damage, and improving the yield of high-quality SiC epitaxial wafers by accurately controlling the cleaning process and regenerating the susceptor surface.
Implementation Method 1
a cleaning chamber in which SiC film deposited on the susceptor is removed
Implementation Method 2
a regeneration chamber in which SiC film is formed on the susceptor
Implementation Method 3
a film-forming chamber in which a SiC epitaxial film is formed on a wafer placed on a susceptor
Data Source
AI summary
According to this embodiment, a semiconductor substrate manufacturing apparatus for epitaxial growth in which gases are supplied to a wafer placed on a susceptor and in which a heater is provided on the back surface of the susceptor. As a result of this epitaxial growth, SiC film is deposited onto the susceptor in the film-forming chamber. The susceptor is then moved into a separate chamber and the SiC film deposited on the susceptor during the epitaxial process is removed. After removal of SiC film, regeneration of the SiC film of the susceptor occurs. This semiconductor substrate manufacturing apparatus makes it possible to remove film deposited on a susceptor during epitaxial growth that would otherwise limit manufacturing yield.