Yttrium Fluoride Coating for Semiconductor Plasma Etching
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Solution Overview
Problem
Existing corrosion-resistant coatings for semiconductor manufacturing equipment fail to effectively prevent metal contamination and particle generation from yttrium-base coatings during plasma etching, leading to reduced production yields and substrate damage.
Innovation Solution
A thermally sprayed yttrium fluoride coating with a specific crystal structure, oxygen concentration, hardness, and porosity, combined with a rare earth oxide lower layer, is used to form a multilayer corrosion-resistant coating that minimizes particle generation and metal contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If yttrium oxide or yttrium fluoride coating is sprayed on substrate to provide corrosion resistance, then plasma resistance is improved, but particle generation and metal contamination increase
Solution Approach 1:
The patent changes the chemical composition parameters of the coating by using yttrium fluoride instead of yttrium oxide, and controls the oxygen concentration (1-6% by weight) and hardness (≥350 HV) to achieve both corrosion resistance and reduced particle generation. The specific crystal structure and compositional parameters are optimized to prevent spall-off while maintaining plasma resistance.
Solution Approach 2:
The patent creates a composite coating system combining yttrium fluoride with specific amounts of other compounds (Y5O4F7, YOF, Y2O3) in controlled ratios. This composite structure provides enhanced corrosion resistance while minimizing particle generation, achieving a balance between protection and contamination reduction.
2Reliability
If coating thickness is increased to improve corrosion resistance, then plasma resistance is improved, but substrate damage from acid penetration increases
Solution Approach 1:
The patent optimizes the coating thickness to a specific range (10-500 μm) and controls the oxygen concentration (1-6% by weight) and porosity (≤5%) to achieve sufficient corrosion resistance while preventing acid penetration. The controlled porosity and composition ensure the coating acts as an effective barrier without allowing acid to reach the substrate interface.
3Object-generated harmful factors
If cleaning is performed to remove reaction product, then particle contamination is reduced, but adhesion strength at coating-substrate interface decreases
Solution Approach 1:
The patent modifies the coating composition by controlling oxygen concentration (1-6% by weight) and porosity (≤5%) to create a coating that resists acid penetration during cleaning. This prevents the acid from reaching the substrate interface, thereby maintaining adhesion strength while still allowing effective removal of reaction products from the coating surface.
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 yttrium fluoride sprayed coating exhibits excellent corrosion resistance in halogen-base gas atmospheres, prevents substrate damage from acid penetration, and reduces particle generation, thereby enhancing the reliability and yield of semiconductor device fabrication.
Implementation Method 1
parts or members of metallic aluminum substrates or aluminum oxide ceramic substrates having coatings formed thereon by spraying yttrium oxide and yttrium fluoride to the substrate surface are known to be fully corrosion resistant
Implementation Method 2
a dielectric film etching system, gate etching system, CVD system and the like are used
Data Source
AI summary
The corrosion resistant coating has a multilayer structure comprising a lower layer in the form of a rare earth oxide sprayed coating having a thickness of 10 to 500 μm and a porosity of up to 5% and an outermost surface layer in the form of an yttrium fluoride sprayed coating.