Silicon Deposition for High Aspect Ratio Etch Profile Control
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Solution Overview
Problem
In semiconductor device formation, existing deposition methods fail to effectively prevent sidewall etching and bowing in high aspect ratio features, leading to poor etch profile control and increased complexity as feature sizes shrink.
Innovation Solution
A method involving the formation of a plasma in a processing chamber using silicon-containing and COS-containing gases to deposit a passivation layer comprising silicon, oxygen, and sulfur, which is highly resistant to etching and reduces sidewall etching, thereby maintaining a straight etch profile and preventing bowing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing deposition methods are used, then deposition can be formed, but sidewall etching and bowing occur in high aspect ratio features
Solution Approach 1:
The patent changes the chemical composition parameters of the deposition layer by using a novel gas mixture containing silicon-containing gas and COS-containing gas. This creates a deposition layer with specific silicon, oxygen, and sulfur composition that provides enhanced etch resistance while maintaining the desired deposition properties, thereby resolving the contradiction between etch profile control and sidewall etching resistance
Solution Approach 2:
The invention creates a composite deposition layer containing multiple elements (silicon, oxygen, sulfur) deposited simultaneously from different gas sources. This composite material structure provides superior etch resistance compared to conventional single-element deposition layers, enabling effective prevention of sidewall etching in high aspect ratio features while maintaining good etch profile control
2Length of moving object
If feature sizes are reduced, then device scaling is achieved, but etch profile control deteriorates
Solution Approach 1:
By adjusting the chemical composition parameters of the deposition layer through controlled gas flow ratios of silicon-containing gas and COS-containing gas, the patent creates a deposition layer with optimized etch resistance properties. This enables maintaining precise etch profile control even as feature sizes are reduced for device scaling
Solution Approach 2:
The deposition process is performed as a preliminary step before etching high aspect ratio features. This preliminary deposition of the specialized silicon-oxygen-sulfur layer prepares the sidewalls with enhanced etch resistance, ensuring that subsequent etching processes maintain excellent profile control regardless of the reduced feature dimensions
3Reliability
If deposition layer is added for etch resistance, then sidewall protection is improved, but process complexity increases
Solution Approach 1:
The patent merges the deposition of multiple elements (silicon, oxygen, sulfur) into a single deposition step by simultaneously flowing silicon-containing gas and COS-containing gas. This combined approach provides comprehensive etch resistance and sidewall protection without requiring multiple separate deposition steps, thereby avoiding increased process complexity while achieving superior etch resistance
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 deposited layer provides excellent etch resistance and improved step coverage, allowing for better control of etch profiles and preventing etch stop, while being easily removable without damaging features, thus enhancing the semiconductor device fabrication process.
Implementation Method 1
A plasma is formed from the silicon containing gas and the COS containing gas in the processing chamber, wherein the plasma provides the deposition over the substrate
Implementation Method 2
A silicon containing gas is flowed into the processing chamber. A COS containing gas is flowed into the processing chamber. A plasma is formed from the silicon containing gas and the COS containing gas in the processing chamber
Data Source
AI summary
A method for processing a substrate in a processing chamber, comprising forming a deposition over the substrate is provided. A silicon containing gas is flowed into the processing chamber. A COS containing gas is flowed into the processing chamber. A plasma is formed from the silicon containing gas and the COS containing gas in the processing chamber, wherein the plasma provides the deposition over the substrate.