Semiconductor Etching with Amine Protection for Selective Silicon Films
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Solution Overview
Problem
Existing etching methods struggle to selectively protect and etch oxygen-containing silicon films on semiconductor wafers, leading to inefficiencies and increased costs due to the need for multiple gas supply systems and prolonged processing times.
Innovation Solution
An etching method that uses amine gas to form a protective film on oxygen-containing silicon films, allowing selective etching of polysilicon films while preventing etching of adjacent silicon oxide and SiOCN films, followed by hydrogen fluoride gas etching, all within a single processing container.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple gas supply systems are used to selectively protect and etch oxygen-containing silicon films, then etching selectivity is improved, but device complexity and manufacturing costs increase
Solution Approach 1:
The amine gas serves multiple functions: it acts as a protective film forming gas to prevent etching of oxygen-containing silicon films, and simultaneously serves as a carrier gas for delivering fluorine-containing etching gases to polysilicon regions. This multi-functionality eliminates the need for separate protective gas and carrier gas supply systems, reducing device complexity while maintaining etching selectivity.
2Manufacturing precision
If multiple processing steps with additional transport steps are used, then etching precision is improved, but productivity decreases
Solution Approach 1:
The patent combines protective film formation and etching operations into a single integrated processing step. The amine gas forms protective films on oxygen-containing silicon surfaces while simultaneously serving as a carrier gas for fluorine-containing etching gases that etch polysilicon regions. This merging of functions allows both protective and etching processes to occur concurrently in the same processing chamber without additional transport steps, thereby maintaining etching precision while significantly improving productivity.
3Reliability
If separate processing chambers are used for protection and etching, then process reliability is improved, but loss of time increases
Solution Approach 1:
The amine gas performs preliminary protective film formation on oxygen-containing silicon surfaces before the fluorine-containing etching gas is introduced. This preliminary protection occurs in-situ within the same processing chamber, eliminating the need for separate transport steps between chambers. The protective film is formed and maintained throughout the etching process, ensuring process reliability while reducing total processing time by eliminating chamber transitions.
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 method reduces manufacturing and operating costs by eliminating the need for additional gas supply systems and enhances throughput by allowing simultaneous processing of polysilicon and silicon oxide films without additional transport steps.
Implementation Method 1
supplying amine gas to a substrate having an oxygen-containing silicon film to form a protective film for preventing etching by etching gases with respect to a surface of the oxygen-containing silicon film
Implementation Method 2
supplying a first etching gas, which is one of the etching gases and is a fluorine-containing gas, and the amine gas to the substrate to etch the oxygen-containing silicon film
Data Source
AI summary
An etching method of supplying etching gases to a substrate to etch a surface of the substrate, includes a protection step of supplying amine gas to the substrate having an oxygen-containing silicon film to form a protective film for preventing etching by the etching gases on a surface of the oxygen-containing silicon film, for protecting the oxygen-containing silicon film, and a first etching step of supplying a first etching gas, which is one of the etching gases and is a fluorine-containing gas, and the amine gas to the substrate to etch the oxygen-containing silicon film.