Group 13 Nitride Substrate Off-Angle Optimization
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Solution Overview
Problem
Reducing the thickness of the epitaxial growth layer on semi-insulating zinc-doped gallium nitride substrates leads to a decrease in electron mobility and sheet carrier density, compromising the properties of the channel layer, especially at high frequency bands.
Innovation Solution
A group 13 nitride single crystal substrate with a specific off-angle range of 0.4° to 1.0° is used, incorporating zinc as a dopant, to maintain excellent epitaxial growth layer properties even when the thickness is reduced to 300 nm or smaller, by optimizing the substrate's surface morphology and carrier mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the thickness of the epitaxial growth layer is reduced to prevent channel layer deterioration, then device performance at high frequency is improved, but electron mobility and sheet carrier density decrease
Solution Approach 1:
The patent applies parameter changes by precisely controlling the off-angle of the substrate surface within 0.4° to 1.0°. This parameter optimization allows the epitaxial growth layer to maintain thickness of 300 nm or smaller while preserving electron mobility and sheet carrier density, thereby resolving the contradiction between high-frequency performance and carrier transport properties.
2Manufacturing precision
If the epitaxial growth layer thickness is reduced to 300 nm or smaller, then channel layer properties are prevented from deteriorating, but step bunching and distortion occur
Solution Approach 1:
By optimizing the substrate off-angle parameter to within 0.4° to 1.0°, the patent prevents step bunching and distortion even when the epitaxial growth layer is thinned to 300 nm or smaller. This parameter control ensures both manufacturing precision of channel layer properties and structural integrity of the epitaxial layers.
Data Source
AI summary
An object is to maintain excellent property of an epitaxial growth layer, even when the epitaxial growth layer on a group 13 nitride single crystal substrate in thinned. A group 13 nitride single crystal substrate is composed of a group 13 nitride single crystal and has a first main face and a second main face. The group 13 nitride single crystal substrate 2 contains zinc as a dopant, and the first main face has an off-angle of 0.4° or more and 1.0° or less.