PEO Coating Reduces Copper Contamination in Plasma Chambers
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Solution Overview
Problem
Plasma chambers and semiconductor processing equipment face challenges with copper contamination, which can lead to device failure due to copper's high diffusion rate in semiconductor materials, and existing protective coatings are either susceptible to corrosive effects or contribute to copper contamination.
Innovation Solution
A method using plasma electrolytic oxidation (PEO) to create an oxide coating with reduced copper concentration and increased magnesium concentration, allowing for the formation of magnesium halide, which enhances corrosion/erosion resistance and reduces copper contamination risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective coating is applied to protect against corrosive effects, then corrosion/erosion resistance is improved, but copper contamination increases
Solution Approach 1:
The invention changes the chemical composition parameters of the protective coating by incorporating magnesium oxide and controlling copper content. The coating is formulated with specific ratios of magnesium oxide (5-50 wt%) in combination with alumina, creating a composite material that provides corrosion resistance while limiting copper contamination to below 5 wt%, and preferably below 1 wt%.
Solution Approach 2:
The invention uses a composite coating material consisting of multiple oxides (alumina, magnesium oxide) rather than a single material. This composite structure combines the corrosion resistance of alumina with the magnesium oxide component that forms protective magnesium halide layers, while maintaining low copper content to prevent contamination.
2Reliability
If existing protective coatings are used, then surface protection is provided, but they are susceptible to corrosive effects or contribute to copper contamination
Solution Approach 1:
The magnesium oxide component acts as an intermediary that reacts with halogen-containing plasmas to form magnesium halide (MgX2) on the coating surface. This magnesium halide layer serves as a protective barrier that prevents direct contact between the corrosive plasma and the underlying substrate, thereby mediating the interaction between the coating and corrosive environment.
Solution Approach 2:
The invention modifies the chemical composition of the protective coating by incorporating magnesium oxide at controlled concentrations (5-50 wt%). This parameter change enables the formation of magnesium halide protective layers during plasma exposure, significantly improving resistance to corrosive effects while maintaining surface protection.
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 PEO process results in a protective layer with improved corrosion/erosion resistance and reduced copper contamination, enabling safer operation in corrosive environments and extending the operational capabilities of plasma sources in semiconductor processing.
Implementation Method 1
oxidizing the surface of the object using a plasma electrolytic oxidation process to form the oxide layer comprising alumina and an oxide of magnesium
Implementation Method 2
converting at least a portion of the magnesium oxide to magnesium halide by exposing the oxide layer to an excited gas that includes a halide or to a plasma that includes a halide
Implementation Method 3
Plasmas are often used to activate gases placing them in an excited state so that they have an enhanced reactivity. In some cases, the gases are excited to produce dissociated gases containing ions, free radicals, atoms and molecules
Implementation Method 4
the gases are excited to produce dissociated gases containing ions, free radicals, atoms and molecules
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A
AI summary
A method for creating an oxide layer having a reduced copper concentration over a surface of an object comprising aluminum and copper for use in a semiconductor processing system. The oxide layer produced using a plasma electrolytic oxidation process has a reduced copper peak concentration, which decreases a risk of copper contamination, and includes magnesium oxides that can be converted to magnesium halide upon exposure to an excited halogen- comprising gas or halogen-comprising plasma to increase the erosion/corrosion resistance of the oxide layer.