Silicon Nitride Plasma Deposition with VHF Phase-Mixed RF Control
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Solution Overview
Problem
Existing film forming methods struggle to achieve both uniform in-plane distribution of film thickness and desired film quality in silicon nitride films, as these parameters are in a trade-off relationship, making it difficult to control both simultaneously.
Innovation Solution
A film forming method that uses TVW RF power generated by phase-controlling and superimposing RF power with different frequencies in the VHF band to plasmarize a processing gas containing silicon, nitrogen, and diluent gases, allowing for enhanced control over film quality while maintaining in-plane distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional single-frequency RF power is used for film formation, then the in-plane distribution of film thickness can be maintained, but the film quality (refractive index, stress) cannot be adjusted with sufficient controllability
Solution Approach 1:
The RF power is segmented into multiple frequency components (first frequency and second frequency in VHF band) that are superimposed to form TVW RF power. This segmentation allows independent control of each frequency component's amplitude and phase, enabling precise adjustment of film quality parameters such as refractive index and stress while maintaining uniform film thickness distribution.
Solution Approach 2:
The invention changes the parameter of RF power from single-frequency to multi-frequency superposition. By adjusting the amplitude ratio and phase difference between the first and second frequency components, the film quality can be controlled with enhanced controllability. The phase difference parameter specifically enables adjustment of refractive index and stress without affecting film thickness uniformity.
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
The method enables adjustable film quality, including refractive index and stress, with improved controllability while maintaining uniform film thickness distribution, using TVW RF power with specific frequency combinations and pressure settings.
Implementation Method 1
plasmarizing the processing gas by supplying, into the processing container, power obtained by phase-controlling and superimposing first power with a first frequency in a VHF band and second power with a second frequency different from the first frequency in the VHF band, and forming a silicon nitride film on the substrate by the plasmarized processing gas
Data Source
AI summary
A film forming method includes: a supply operation of supplying a processing gas into a processing container in which a substrate is accommodated, the processing gas including a silicon-containing gas, a nitrogen-containing gas, and a diluent gas; and a film forming operation of plasmarizing the processing gas by supplying, into the processing container, power obtained by phase-controlling and superimposing first power with a first frequency in a VHF band and second power with a second frequency different from the first frequency in the VHF band, and forming a silicon nitride film on the substrate by the plasmarized processing gas.