Semiconductor Exhaust System Plasma Cleaning
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Solution Overview
Problem
In conventional epitaxial growth systems, unreacted or excessive gases can form solid-phase by-products along the exhaust pipe and over pressure control valves, leading to malfunctioning of the pressure control system.
Innovation Solution
The system incorporates a novel exhaust system design with multiple pipes to direct etching gases and radicals generated by a remote plasma source into the exhaust pipe to etch the by-products, and a diluted gas is used to prevent damage from the etching process, ensuring that the by-products are converted back to a gaseous phase and removed, thereby maintaining the integrity of the pressure control valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If unreacted gases are exhausted through the exhaust pipe, then the pressure in the reaction chamber is controlled, but solid-phase by-products form along the pipe and over the pressure control valve
Solution Approach 1:
The patent applies remote plasma processing to convert the harmful solid-phase by-products into beneficial gaseous phases. The plasma generates reactive species that chemically react with the deposited by-products, transforming them from harmful deposits into removable gaseous compounds that can be evacuated through the exhaust system.
Solution Approach 2:
The patent introduces remote plasma as an intermediary substance between the exhaust pipe and the by-products. This plasma acts as a mediator that indirectly processes the by-products without requiring direct contact between processing components and the deposits, enabling cleaning while maintaining system integrity.
2Reliability
If etching gas is applied to remove by-products, then the pressure control valve is protected, but damage may occur from the etching process itself
Solution Approach 1:
The patent uses remote plasma as an intermediary that delivers the etching action without requiring the etching gas to be in direct contact with sensitive components. The plasma processes the by-products in the exhaust pipe while the diluted gas protects downstream components from excessive etching damage.
Solution Approach 2:
The patent controls the concentration and flow parameters of the etching gas and diluted gas to optimize the etching process. By adjusting these parameters, the system achieves effective by-product removal while limiting potential damage to system components through controlled exposure levels.
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 approach effectively prevents the formation of solid-phase by-products, maintaining the controllability of the pressure control valve and ensuring stable chemical reactions within the reaction chamber by converting the by-products into a gaseous phase for removal.
Implementation Method 1
a second pipe that is coupled to the exhaust pipe and a remote plasma source such that the second pipe is configured to provide a radical into the exhaust pipe
Implementation Method 2
etching gas into the exhaust pipe to etch a layer that is formed, at least in part, of gas that is not reacted in a chamber coupled to the exhaust pipe
Implementation Method 3
a first pipe that is coupled to the exhaust pipe and configured to provide an etching gas into the exhaust pipe
Implementation Method 4
a third pipe that is coupled to the exhaust pipe and configured to provide diluted gas into the exhaust pipe
Data Source
AI summary
An apparatus for a semiconductor process includes an exhaust pipe coupled to a reaction chamber and a pump; a pressure control valve that is coupled to the exhaust pipe and configured to control a pressure value in the reaction chamber; a first pipe that is coupled to the exhaust pipe and etching gas source such that the first pipe is configured to provide an etching gas into the exhaust pipe; a second pipe that is coupled to the exhaust pipe and a radical generator such that the second pipe is configured to provide a radical into the exhaust pipe; and a third pipe that is coupled to the exhaust pipe and a diluted gas source such that the third pipe is configured to provide diluted gas into the exhaust pipe.