GaAs Substrate Compressive Strain Slip Suppression
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Solution Overview
Problem
GaAs crystals and wafers experience slip during semiconductor layer growth due to high temperature elevation rates, leading to dislocation and potential device failure.
Innovation Solution
A gallium arsenide single crystal and substrate with a compressive residual strain in the tangential direction of the outer circumferential portion, extending between specific inner and outer surface locations, are developed to suppress slip during semiconductor layer growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the temperature elevation rate is high during semiconductor layer growth, then productivity is improved, but slip occurs leading to dislocation and device failure
Solution Approach 1:
The patent applies preliminary anti-action by introducing compressive residual strain in the outer circumferential portion of the GaAs single crystal substrate before semiconductor layer growth. This pre-applied compressive strain counteracts the tensile stress that develops during high-rate temperature elevation, preventing slip and dislocation formation. The compressive strain acts as a preventive measure against the harmful tensile stress that would otherwise cause device failure.
Solution Approach 2:
The patent changes the strain parameter in the substrate by creating a specific residual strain distribution where the outer circumferential portion (from 10mm inward from the outer surface to 5mm inward from the outer surface) has compressive strain. This parameter change in the stress/strain state of the substrate allows it to withstand higher temperature elevation rates without causing slip, thus resolving the contradiction between productivity and reliability.
2Productivity
If the temperature elevation rate is high during semiconductor layer growth, then manufacturing efficiency is improved, but slip occurs leading to dislocation
Solution Approach 1:
The compressive residual strain introduced in the outer circumferential portion serves as a preliminary countermeasure against the tensile stress generated during rapid heating. This pre-established compressive stress field prevents slip planes from forming, thereby maintaining high crystal quality even when manufacturing efficiency is improved through faster temperature elevation rates.
Solution Approach 2:
By modifying the strain parameter distribution in the substrate (creating compressive strain in the outer circumferential region), the patent enables the material to tolerate higher heating rates without sacrificing crystal quality. This parameter change decouples the relationship between heating rate and dislocation formation, allowing both high manufacturing efficiency and high manufacturing precision to coexist.
3Reliability
If compressive residual strain is introduced in the outer circumferential portion, then slip is suppressed, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by introducing compressive residual strain specifically in the outer circumferential portion of the GaAs single crystal substrate (from 10mm inward from the outer surface to 5mm inward from the outer surface), rather than uniformly throughout the entire substrate. This localized strain introduction targets the specific region where slip is most likely to occur during thermal processing, effectively suppressing slip while minimizing the overall complexity of the manufacturing process.
Data Source
AI summary
A gallium arsenide single crystal including a straight body portion having a cylindrical shape, wherein a residual strain in a tangential direction in an outer circumferential portion is a compressive strain, the outer circumferential portion extending between an inner circumferential surface located 10 mm inward from an outer circumferential surface of the straight body portion toward a central axis and a location located 5 mm inward from the outer circumferential surface. There is a gallium arsenide single crystal substrate, wherein a residual strain in a tangential direction in an outer circumferential portion is a compressive strain, the outer circumferential portion extending between an inner circumference located 10 mm inward from an outer circumference toward a center and a location located 5 mm inward from the outer circumference.