Nitride Semiconductor Substrate Edge Chamfering for Crack Prevention
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Solution Overview
Problem
Existing nitride semiconductor substrates with semipolar planes lack effective chamfered portions to prevent cracking and chipping, which hampers the manufacturing yield of semiconductor devices.
Innovation Solution
A nitride semiconductor substrate with a main surface inclined at 71° to 79° relative to the (0001) plane or (000-1) plane, featuring a chamfered portion at the edge with an angle of 5° to 45° relative to adjacent surfaces, effectively reducing cracking and chipping during device fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a chamfered portion is provided at the edge of the outer periphery in the GaN substrate, then chipping and cracking are prevented, but the substrate structure becomes more complex and manufacturing difficulty increases
Solution Approach 1:
The patent specifies precise angular parameters for the chamfered portion (5° to 45° relative to the main surface) and for the main surface itself (71° to 79° relative to the (0001) plane). By optimizing these geometric parameters, the substrate achieves both structural integrity and manufacturability, resolving the contradiction between preventing chipping/cracking and maintaining simple structure.
2Productivity
If the main surface is inclined at a specific angle (71° to 79°) relative to the (0001) plane, then oscillation yield is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent identifies and specifies an optimal angular range (71° to 79°) for the main surface inclination relative to the (0001) plane. This parameter optimization improves oscillation yield while providing clear manufacturing specifications that balance precision requirements with practical fabricability.
3Reliability
If the chamfered portion is inclined at a smaller angle (5° to 45°), then cracking and chipping are suppressed, but the edge geometry becomes more complex
Solution Approach 1:
The patent specifies the chamfered portion inclination angle within the range of 5° to 45° relative to the main surface. This parameter optimization effectively suppresses cracking and chipping while maintaining manageable edge geometry for manufacturing, resolving the contradiction between crack resistance and geometric simplicity.
Data Source
AI summary
A nitride semiconductor substrate having a main surface serving as a semipolar plane and provided with a chamfered portion capable of effectively preventing cracking and chipping, a semiconductor device fabricated using the nitride semiconductor substrate, and a method for manufacturing the nitride semiconductor substrate and the semiconductor device are provided. The nitride semiconductor substrate includes a main surface inclined at an angle of 71° or more and 79° or less with respect to the (0001) plane toward the [1-100] direction or inclined at an angle of 71° or more and 79° or less with respect to the (000-1) plane toward the [−1100] direction; and a chamfered portion located at an edge of an outer periphery of the main surface. The chamfered portion is inclined at an angle θ1 or θ2 of 5° or more and 45° or less with respect to adjacent one of the main surface and a backside surface on a side opposite to the main surface. Accordingly, cracking and chipping occurring from the edge of the outer periphery of the nitride semiconductor substrate can be effectively suppressed.