Cooling Gas Filter Structure to Suppress Plasma Discharge
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Solution Overview
Problem
Conventional plasma processing apparatuses face issues with reduced etching rates and equipment downtime due to discharge generation, which affects substrate processing efficiency and manufacturing yield.
Innovation Solution
A substrate processing apparatus with a gas filter featuring regions of different dielectric materials, inclined with respect to the gas flow path, to suppress discharge by colliding electrons and guide cooling gas effectively, preventing discharge and enhancing processing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling gas is supplied through a gas filter in a conventional plasma processing apparatus, then the substrate temperature is uniformized, but discharge is generated which lowers etching rate and reduces manufacturing yield
Solution Approach 1:
The patent changes the dielectric constant parameter of the gas filter by using a composite structure with a dielectric layer and a conductive layer. This parameter change prevents discharge generation while maintaining cooling gas flow, thereby resolving the contradiction between temperature uniformity and etching rate.
Solution Approach 2:
The gas filter is constructed using composite materials - specifically a dielectric layer and a conductive layer combined together. This composite structure prevents discharge by controlling the electric field distribution while allowing cooling gas to pass through, thus maintaining both temperature uniformity and high etching rate.
2Temperature
If cooling gas is supplied through a gas filter, then substrate temperature is controlled, but equipment must be stopped for maintenance which reduces manufacturing yield
Solution Approach 1:
By changing the dielectric parameter of the gas filter through the composite layer structure, the patent prevents discharge generation that would otherwise require equipment shutdown for maintenance. This reduces equipment downtime while maintaining temperature control capability.
Solution Approach 2:
The patent designs the gas filter with a conductive layer that can be easily replaced. When the conductive layer becomes carbonized, it can be quickly replaced without replacing the entire gas filter, thereby minimizing equipment downtime and maintenance loss.
3Productivity
If a conductive layer is added to the gas filter to prevent discharge, then etching efficiency is improved, but device complexity increases
Solution Approach 1:
The gas filter uses a composite structure of dielectric layer and conductive layer. This composite design prevents discharge and improves etching efficiency while keeping the overall structure relatively simple and manageable.
Solution Approach 2:
The gas filter is segmented into distinct functional layers - a dielectric layer and a conductive layer. This segmentation allows each layer to perform its specific function (insulation and discharge prevention respectively) while maintaining a relatively simple overall structure that is easier to manufacture and maintain.
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 prevents discharge, improves etching efficiency, reduces equipment downtime, and enhances manufacturing yield by ensuring consistent substrate processing performance.
Implementation Method 1
the gas filter includes one or more wall surfaces at least partially defining a gas flow path for the cooling gas, wherein the gas filter includes a first region including a first material and a second region including a second material having a dielectric constant, the first and second materials having different respective dielectric constants
Implementation Method 2
the first region and the second region are configured to cause the cooling gas flowing through the gas flow path to flow upwardly concurrently with colliding with the one or more wall surfaces at least partially defining the gas flow path
Implementation Method 3
a substrate is adsorbed on the lower dry electrode by an electrostatic chuck
Implementation Method 4
the cooling gas (for example, helium gas) is sprayed from the gas filter toward a bottom surface of the substrate to uniformize temperature distribution of the substrate
Implementation Method 5
when plasma is generated on the substrate, a voltage equal to a voltage generated between the lower electrode and the plasma is generated between the lower electrode and a member by high frequency power. In this case, electrons in the cooling gas are accelerated in the gas filter to generate discharge
Data Source
AI summary
A substrate processing apparatus includes a process chamber having an internal space; upper and lower electrode portions facing each other in the internal space; and a gas supply unit configured to supply cooling gas to a bottom surface of a substrate seated on the lower electrode portion. The gas supply unit may include a gas supply source outside the process chamber and configured to provide a cooling gas, and a gas filter connected to the gas supply source and including one or more wall surfaces at least partially defining a gas flow path for the cooling gas. The gas filter may include a first and second regions formed of respective materials having different dielectric constants. The first and second regions may be configured so that the cooling gas flowing along the gas flow path flows upwardly concurrently with colliding with a wall surface of the gas flow path.