Ice Particle Blasting for Sputter Target Surface Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In sputtering processes, scattered metal particles deposit on unintended surfaces like shields and target sidewalls, leading to flaking and contamination, which reduces target lifetime and can cause defects in the sputtered pattern.
Innovation Solution
Optimizing textured target surfaces by blasting them with ice particles to remove cantilevered structures and contaminants, using methods like bead blasting, grit blasting, plasma spraying, or twin-wire-arc spraying, and then using a particle blasting device with ice particles to create a smooth, clean surface that enhances adhesion and reduces particle generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If arc spraying or plasma spraying is used to texture target surfaces, then surface roughness is increased to limit stress build-up, but the coating may release due to inconsistent roughness and trapped contaminants
Solution Approach 1:
The method performs preliminary cleaning of the textured surface using ion bombardment or plasma treatment before deposition. This preliminary action removes contaminants and oxides that would otherwise be trapped in the rough surface, ensuring proper adhesion of subsequent deposited layers while maintaining the stress-relieving roughness structure
Solution Approach 2:
The invention replaces mechanical cleaning methods (which might damage the textured surface) with ion bombardment or plasma cleaning. This substitution allows effective removal of contaminants and formation of a reactive surface layer without mechanically altering the carefully controlled roughness profile, thereby maintaining both stress limitation and coating retention
2Stability of the object's composition
If bead blasting or grit blasting is used to texture surfaces, then surface roughness is increased, but blasting material becomes embedded in the surface and releases during thermal cycling
Solution Approach 1:
The method extracts and removes embedded blasting material and contaminants from the textured surface using ion bombardment or plasma cleaning. This extraction process eliminates the source of harmful particles that would otherwise be released during thermal cycling, while preserving the roughness structure needed for stress management
Solution Approach 2:
The invention changes the physical and chemical state of the surface through ion bombardment or plasma treatment. This creates a reactive, clean surface layer that improves adhesion and prevents the release of embedded particles during subsequent thermal cycling, effectively converting a harmful condition into a beneficial surface state
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 optimized textured surfaces improve adhesion and retention of deposited particles, reducing the generation of undesirable particles and extending target lifetime by minimizing stress build-up and contamination, while maintaining a high surface area for deposition.
Implementation Method 1
blasting them with ice particles to remove cantilevered structures and contaminants
Implementation Method 2
The ice particles may be sublimable particles, such as frozen carbon dioxide or dry ice
Implementation Method 3
two wires with an opposing electrical charge are fed through a motorized gun. As the wires are fed through the gun, they almost touch and create an electrical arc
Implementation Method 4
A compressed gas is fed through an orifice behind the electrical arc, atomizing the metal and propelling it onto the surface to be coated
Implementation Method 5
a metal coating is sprayed onto target surfaces to increase the roughness of the sidewalls
Data Source
AI summary
Methods for treating texturized surfaces of sputter targets in order to improve adhesion and retention of deposited particles thereon. The target surfaces may first be texturized by a precursor texturizing method such as bead blasting, grit blasting, plasma spraying, or a twin-wire-arc spraying (TWAS) method. The thus textured surface is then sprayed or blasted with ice particles to form an optimized textured surface. The ice particles may comprise sublimable particles such as frozen carbon dioxide or dry ice. Also, argon may be used as exemplary ice particles.