Backside Gas Flow Switching for Plasma-Safe Substrate Supports
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor processing systems face issues with plasma byproducts damaging substrate support components during cleaning operations, leading to increased replacement costs and reduced performance.
Innovation Solution
Utilizing non-reactive backside gases during both substrate processing and cleaning operations, with controlled flow rates to limit plasma byproduct ingress and protect substrate support components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma cleaning operation is performed to strip residual materials from chamber surfaces, then cleaning effectiveness is improved, but substrate support components are damaged by plasma byproducts
Solution Approach 1:
A gas flow system is introduced as an intermediary between the plasma cleaning operation and the substrate support components. The gas flows through the substrate support during cleaning to create a protective barrier that prevents plasma byproducts from directly contacting and damaging the substrate support, while allowing the cleaning plasma to effectively strip residual materials from chamber surfaces.
Solution Approach 2:
An inert gas atmosphere is established by flowing non-reactive gas through the substrate support during plasma cleaning operations. This inert environment protects the substrate support components from chemical damage by plasma byproducts while maintaining the cleaning effectiveness on chamber surfaces, as the inert gas does not react with either the plasma or the substrate support materials.
2Reliability
If backside gas flow rate is increased to protect substrate support during cleaning, then component protection is improved, but thermal control during processing is degraded
Solution Approach 1:
The backside gas flow rate is made dynamic and variable rather than fixed. The system automatically adjusts the flow rate based on the operational phase: a first flow rate is used during substrate processing to maintain proper thermal control, and a second higher flow rate is used during plasma cleaning operations to enhance protection of substrate support components. This dynamic adjustment resolves the contradiction between thermal control and component protection.
Solution Approach 2:
The gas flow rate parameter is changed based on operational conditions. During substrate processing, the flow rate is maintained at a level that ensures adequate thermal control of the substrate support. During plasma cleaning operations, the flow rate is increased to provide enhanced protection against plasma byproduct damage. This parameter change allows the system to optimize performance for each specific operational phase.
3Productivity
If substrate support is exposed to plasma byproducts during cleaning, then chamber cleaning is effective, but substrate support lifetime is reduced
Solution Approach 1:
Protective gas flow is established before and during the plasma cleaning operation to preemptively protect the substrate support components. The gas flows through the substrate support in advance of plasma byproduct exposure, creating a protective barrier that prevents damage accumulation, thereby extending substrate support lifetime while maintaining cleaning efficiency.
Solution Approach 2:
The system uses the plasma cleaning operation itself to benefit the substrate support by directing gas flow that carries plasma byproducts away from the substrate support components. The harmful plasma byproducts are converted into a beneficial cleaning action on chamber surfaces while being simultaneously diverted from the substrate support, thus protecting it and extending its operational lifetime.
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
Improves thermal control and reduces component damage, enhancing the lifetime and performance of processing chambers while lowering operational costs.
Implementation Method 1
A backside purge gas may be delivered between the substrate seated on the chuck and the chuck surface to regulate the temperature of the wafer
Implementation Method 2
a chamber cleaning operation may be performed, during which plasma byproducts are utilized to strip residual materials from chamber surfaces
Data Source
AI summary
Methods of semiconductor processing may include performing a process on a semiconductor substrate. The semiconductor substrate may be seated on a substrate support positioned within a processing region of a semiconductor processing chamber. The methods may include flowing a first backside gas through the substrate support at a first flow rate. The methods may include removing the semiconductor substrate from the processing region of the semiconductor processing chamber. The methods may include performing a plasma cleaning operation within the processing region of the semiconductor processing chamber. The methods may include flowing a second backside gas through the substrate support at a second flow rate. At least a portion of the second backside gas may flow into the processing region through accesses in the substrate support.