Indium Target Surface Roughness Control for Sputtering Arcing
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Solution Overview
Problem
The melt casting method for producing indium targets results in a roughened surface due to oxide film formation, leading to arcing issues during sputtering, which is exacerbated by the softness of indium, causing inefficiencies in the formation of thin-film solar cells.
Innovation Solution
The surface roughness of indium targets is controlled by cutting processing to achieve an arithmetic average roughness (Ra) of 1.6 µm or less and a ten-point height of irregularities (Rz) of 15 µm or less, using scrapers made of materials like stainless steel or ceramics, to prevent arcing during sputtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the surface of the indium target is abraded to remove the oxide film, then the oxide film is removed, but the surface is roughened causing arcing during sputtering
Solution Approach 1:
The invention changes the surface roughness parameter from a rough state (causing arcing) to a controlled smooth state (Ra ≤ 1.6 μm). This is achieved by controlling the cutting depth and tool parameters during the cutting process to achieve the optimal surface finish that prevents arcing while maintaining oxide film removal
Solution Approach 2:
The invention converts the harmful effect of surface roughness into a beneficial controlled surface finish. By deliberately controlling the cutting process to achieve a specific roughness range (Ra ≤ 1.6 μm), the previously harmful rough surface becomes a controlled surface that prevents arcing while maintaining effective oxide film removal
2Reliability
If cutting processing is applied to reduce surface roughness, then arcing is restrained, but the manufacturing process becomes more complex
Solution Approach 1:
The invention performs the surface cutting operation as a preliminary step before sputtering. By controlling the surface roughness to Ra ≤ 1.6 μm in advance, the subsequent sputtering process proceeds without arcing issues, eliminating the need for additional surface treatment steps and simplifying the overall manufacturing 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 effectively reduces arcing occurrences, ensuring smoother target surfaces that enhance the sputtering process and improve the efficiency of thin-film solar cell production by maintaining a controlled surface finish.
Implementation Method 1
by subjecting the surface of the indium target manufactured by the melt casting method to cutting processing
Implementation Method 2
an indium ingot obtained by flow casting of indium into a mold
Data Source
AI summary
Provided are an indium target that can favorably inhibit the occurrence of arcing, and a method for producing the indium target. The indium target having a surface arithmetic average roughness (Ra) of 1.6 µm or less.