Movable Edge Ring and Gas Injection for Etch Uniformity
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Solution Overview
Problem
Substrate processing systems face challenges in achieving uniform etch rates and controlling etch uniformity due to variations in pocket depth, edge ring geometry, and gas flow patterns, leading to issues like redeposition of etch by-products and non-uniform material distribution across the substrate.
Innovation Solution
A substrate support system with a variable depth edge ring and a controller that dynamically adjusts the edge ring height and gas injection parameters to modulate gas flow recirculation and by-product deposition, ensuring consistent etch uniformity by associating edge ring height with specific gas injection parameters and etch by-product distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a fixed edge ring geometry is used, then the device structure is simple, but etch uniformity deteriorates due to variations in pocket depth and gas flow patterns
Solution Approach 1:
The edge ring is made movable rather than fixed, allowing its height to be dynamically adjusted during substrate processing. The controller raises or lowers the edge ring based on real-time feedback about material distribution, enabling the system to adapt to variations in pocket depth and gas flow patterns, thereby achieving uniform etching across the substrate.
Solution Approach 2:
The system changes the physical parameter of edge ring height to control the pocket depth. By adjusting this geometric parameter dynamically, the system optimizes gas flow patterns and plasma distribution, resolving the contradiction between maintaining simple structure and achieving precise etch uniformity.
2Productivity
If gas flow rate is increased to improve etch rate, then productivity increases, but by-product redeposition worsens due to enhanced gas flow recirculation
Solution Approach 1:
The controller uses feedback from measurements of material distribution on the substrate to adjust gas flow rates and edge ring position. When by-product redeposition is detected, the system responds by modifying gas flow parameters or edge ring height to reduce recirculation, thereby maintaining high etch rates while minimizing harmful redeposition.
Solution Approach 2:
The system extracts and removes by-products from the gas flow recirculation path by adjusting the edge ring position to alter flow patterns, preventing their redeposition on the substrate while maintaining productive etching conditions.
3Manufacturing precision
If edge ring height is adjusted to control material distribution, then etch uniformity improves, but device complexity increases due to movable components
Solution Approach 1:
The movable edge ring serves multiple functions: it confines plasma, protects the substrate support from erosion, and acts as a variable depth structure to control gas flow and material distribution. By making one component multi-functional, the system achieves precise control without proportionally increasing overall device complexity.
Solution Approach 2:
The system uses its own movable edge ring mechanism to self-regulate material distribution and by-product removal, eliminating the need for separate complex control systems for each function. The integrated design allows the edge ring to simultaneously perform confinement, protection, and uniformity control.
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 solution effectively controls etch uniformity by dynamically adjusting the edge ring height and gas injection parameters, reducing by-product redeposition and achieving consistent etch rates across the substrate, thereby improving processing outcomes.
Implementation Method 1
directing first process gases toward the inner portion using the gas distribution device
Implementation Method 2
modulate gas flow recirculation and by-product deposition
Implementation Method 3
gas mixtures including one or more precursors may be introduced into the processing chamber and plasma may be used to initiate chemical reactions
Implementation Method 4
A controller determines distribution of material deposited on the substrate during processing
Data Source
AI summary
A substrate processing system for a substrate processing chamber includes a gas delivery system configured to direct process gases toward a substrate support in the substrate processing chamber and a controller. During processing of a substrate arranged on the substrate support the controller is configured to calculate, based on at least one of a position of an edge ring of the substrate support and characteristics of the process gases directed toward the substrate support, a distribution of etch by-product material redeposited onto the substrate during processing and, in response to the calculated distribution, generate control signals to cause an actuator to selectively adjust a position of the edge ring relative to the substrate and cause the gas delivery system to selectively adjust a flow of the process gases.