Microwave Plasma Cleaning Method for Uneven Surfaces
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Solution Overview
Problem
Existing cleaning methods for microwave plasma processing apparatuses are inefficient in removing deposits from the uneven surfaces and edges of components, leading to particle generation and reduced yield during film formation processes.
Innovation Solution
A method that adjusts the internal pressure of the processing container to match the size of the cleaning target parts, generating plasma of varying densities to effectively clean the ceiling surfaces, window parts, and gas holes by controlling the plasma diffusion distance, allowing for localized and comprehensive cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single pressure condition is used for cleaning, then the cleaning process is simple, but deposits on uneven surfaces and edges cannot be effectively removed
Solution Approach 1:
The patent applies parameter changes by adjusting the pressure condition in two distinct steps: first at a lower pressure to generate diffuse plasma for reaching uneven surfaces and edges, then at a higher pressure to generate dense plasma for effective deposit removal. This dynamic parameter adjustment resolves the contradiction between process simplicity and cleaning effectiveness.
Solution Approach 2:
The cleaning process is segmented into two distinct pressure-based steps: a first cleaning step at lower pressure and a second cleaning step at higher pressure. Each step targets different aspects of deposit removal, with the segmentation allowing optimization for both surface accessibility and cleaning intensity without requiring a single complex process.
2Manufacturing precision
If plasma density is increased to improve deposit removal, then cleaning effectiveness improves, but plasma diffusion distance decreases reducing coverage
Solution Approach 1:
The patent employs periodic action by alternating between two pressure conditions in sequence: first applying lower pressure to enable plasma diffusion across the chamber, then applying higher pressure to concentrate plasma density for effective deposit removal. This periodic switching resolves the contradiction between plasma diffusion distance and density.
3Area of stationary object
If pressure is reduced to increase plasma diffusion distance, then coverage area increases, but plasma density decreases reducing cleaning power
Solution Approach 1:
The patent applies dynamics by making the pressure condition variable rather than fixed, transitioning from a first pressure condition to a second pressure condition based on the cleaning requirements. This dynamic adjustment allows the system to achieve both wide plasma coverage and high cleaning power at different stages of the cleaning process.
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 enables thorough removal of deposits from all surfaces, preventing particle generation and improving the coating state of pre-coating films, thus enhancing the film formation process and reducing yield loss.
Implementation Method 1
perform a cleaning process using plasma of the cleaning gas
Implementation Method 2
a microwave plasma processing apparatus which has a processing container and a microwave radiation part
Implementation Method 3
cleaning step of adjusting an internal pressure of the processing container to a pressure corresponding to a size of a cleaning target part, among parts within the processing container including a wall surface of the processing container, the microwave radiation part, and the window part, while supplying a cleaning gas, and performing a cleaning process using plasma of the cleaning gas
Data Source
AI summary
A method for cleaning a microwave plasma processing apparatus which has a processing container and a microwave radiation part, and which has a window part provided at a position where the microwave radiation part is disposed in the processing container, includes a cleaning step of adjusting a pressure to a pressure corresponding to a size of a cleaning target part, among parts within the processing container including a wall surface of the processing container, the microwave radiation part, and the window part, while supplying a cleaning gas, and performing a cleaning process using plasma of the cleaning gas.