Anodized Titanium Dielectric Layer for High-Voltage Thermal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrostatic chucks in plasma etching apparatuses face challenges in achieving high withstand voltage and thermal stability due to differences in thermal expansion coefficients between alumina and aluminum, leading to potential dielectric breakdown and cracking.
Innovation Solution
An anodized titanium material with a porous first anodized titanium layer is developed, featuring a withstand voltage of 500 V or more at 25°C, Vickers hardness of 200 or more, film thickness of 20 μm or more and less than 80 μm, and surface roughness within specific limits, thereby improving thermal stability and preventing dielectric breakdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If alumina is used as the dielectric layer in electrostatic chucks, then insulation performance is improved, but thermal stability deteriorates due to large thermal expansion coefficient difference with aluminum substrate
Solution Approach 1:
The patent changes the material parameter (thermal expansion coefficient) by replacing alumina with titanium oxide, which has a thermal expansion coefficient closer to aluminum, thereby reducing thermal stress while maintaining insulation performance
Solution Approach 2:
The patent uses a composite structure consisting of an aluminum substrate with a titanium oxide dielectric layer formed through anodization, combining the advantages of both materials to achieve both electrical insulation and thermal stability
2Force
If high voltage is applied to achieve strong electrostatic holding force, then substrate holding capability is improved, but dielectric breakdown risk increases
Solution Approach 1:
The patent changes the dielectric material from alumina to titanium oxide, which provides higher breakdown voltage, enabling stronger electrostatic holding forces to be applied without risking dielectric breakdown
3Reliability
If anodized titanium layer thickness is increased to improve withstand voltage, then insulation performance is improved, but surface roughness increases
Solution Approach 1:
The patent optimizes the anodization process parameters (electrolyte composition, temperature, voltage, time) to produce a titanium oxide layer with controlled thickness and fine pore structure, achieving both high withstand voltage and acceptable surface roughness
Solution Approach 2:
The patent utilizes the porous structure formed during anodization, where the pore walls provide insulation while the controlled porosity allows for optimized electrical and mechanical properties without excessive surface roughness
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 anodized titanium material effectively enhances the withstand voltage and thermal stability, preventing dielectric breakdown and cracking even under high-temperature plasma etching conditions, making it suitable for electrostatic chucks and other vacuum applications.
Implementation Method 1
anodized titanium material includes a titanium base material and an anodized titanium layer
Implementation Method 2
anodized titanium layer includes a porous first anodized titanium layer
Implementation Method 3
The anodized titanium layer has a withstand voltage at 25° C. of 500 V or more
Implementation Method 4
differences in thermal expansion coefficients between alumina and aluminum, leading to potential dielectric breakdown and cracking
Data Source
AI summary
An anodized titanium material includes a titanium base material and an anodized titanium layer. The anodized titanium layer is provided on a surface of the titanium base material. The anodized titanium layer includes a porous first anodized titanium layer. The anodized titanium layer has a withstand voltage at 25° C. of 500 V or more, a Vickers hardness of 200 or more, a film thickness of 20 μm or more and less than 80 μm, an arithmetic average roughness Ra of a surface of less than 1.6 μm, and a maximum height roughness Rz of the surface is less than 6.3 μm. In both of a section perpendicular to a thickness direction of the first anodized titanium oxide layer and the surface, no pore sections having a shape capable of including a circle having a diameter of 0.5 μm or more are observed.