Surface-Emitting Mesa Structure for Stress-Resistant Light Emission
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Solution Overview
Problem
Conventional surface-emitting elements face issues with stress resistance at the bottom portion of the mesa, leading to cracks and reduced reliability due to local stress concentration and potential chemical reactions from foreign matter intrusion.
Innovation Solution
The surface-emitting element features a mesa with a convex portion on its outer peripheral surface, covered by a protective film, and a conductive film on the protective film's peripheral region, enhancing stress resistance and preventing film peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mesa bottom portion is made flat and vertical, then the manufacturing process is simple, but stress concentrates at the bottom leading to cracks and reduced reliability
Solution Approach 1:
The patent applies curvature by forming a convex portion on the outer peripheral surface of the mesa bottom portion, replacing the flat vertical design with a curved profile. This curvature distributes stress more evenly across the mesa bottom, preventing stress concentration and crack formation while maintaining manufacturing feasibility through standard semiconductor processing techniques.
2Reliability
If the outer peripheral surface of the mesa is left exposed, then the structure is simple, but foreign matter can intrude causing chemical reactions and degradation
Solution Approach 1:
The patent employs thin film layers (protective film and conductive film) to cover the outer peripheral surface of the mesa. These films act as barriers that prevent foreign matter intrusion and chemical reactions while maintaining the electrical and mechanical functionality of the device. The flexible nature of these films allows them to conform to the convex portion geometry.
3Reliability
If a protective film is applied on the convex portion, then stress resistance improves, but the film may peel due to stress concentration
Solution Approach 1:
The convex portion's curved geometry on the mesa bottom provides a gradual transition that reduces stress concentration points. When the protective film is applied over this curved surface, the stress is distributed more uniformly, preventing film peeling while maintaining strong adhesion. The curvature acts as a stress-distributing feature that protects both the mesa structure and the film layer.
Data Source
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AI summary
To provide a surface-emitting element capable of improving stress resistance at a bottom portion of a mesa. A surface-emitting element according to the present technology includes a first structure including a first semiconductor structure, a second structure including a second semiconductor structure stacked with the first structure, and a light-emitting layer arranged between the first and second structures and including a light-emitting region, in which a mesa including at least a part of the first semiconductor structure, the light-emitting layer, and the second semiconductor structure and having a bottom portion in the at least a part is formed, and an outer peripheral surface of the bottom portion has a convex portion that circles around the light-emitting region in plan view. With the surface-emitting element according to the present technology, a surface-emitting element capable of improving stress resistance at a bottom portion of a mesa can be provided.