LED Trench Structure for Uniform Current Spreading
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Solution Overview
Problem
Conventional light emitting diodes (LEDs) face issues with uneven current distribution, leading to reduced brightness and increased initial light decay due to vertical current injection, which causes current accumulation and heat concentration.
Innovation Solution
Incorporating a first trench that penetrates the active layer and extends into the semiconductor layers, forcing current to flow horizontally and improving uniformity, which is achieved by using a dry etching method to form the trench with specific dimensions and filling it with insulating materials to prevent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If current is allowed to flow vertically through the semiconductor layers, then current injection efficiency is improved, but current accumulation and heat concentration occur leading to reduced reliability
Solution Approach 1:
The patent introduces a first trench that segments the vertical current path into separate regions. The trench divides the semiconductor layer into multiple current flow paths, preventing current accumulation in any single region while maintaining overall current injection efficiency. This segmentation resolves the contradiction by distributing current flow horizontally rather than allowing concentrated vertical flow.
Solution Approach 2:
The patent applies local quality by creating a specific structural feature (the first trench) at a particular location within the semiconductor layer. This local modification changes the current flow characteristics in that specific region, forcing current to flow horizontally around the trench rather than vertically through it, thereby preventing local current accumulation and heat concentration while maintaining overall device performance.
2Reliability
If current spreading paths are dispersed in multiple directions, then current distribution is improved, but brightness of light output is reduced
Solution Approach 1:
The patent transitions the current flow from a primarily vertical one-dimensional path to a two-dimensional horizontal flow pattern by introducing the first trench. This dimensional change forces current to spread horizontally across the semiconductor layer rather than flowing directly vertical, improving current uniformity while maintaining effective light output through the optimized current distribution.
Data Source
AI summary
A light emitting diode includes: a substrate; an epitaxial structure disposed on a surface of the substrate and including a first semiconductor layer, an active layer, and a second semiconductor layer sequentially disposed in a direction away from the substrate; a first electrode disposed on the first semiconductor layer; a second electrode disposed on the second semiconductor layer; and a first trench disposed on a surface of the second semiconductor layer away from the substrate, penetrating the active layer starting from the surface of the second semiconductor layer away from the substrate, and extending to a portion of the first semiconductor layer. In the disclosure, the arrangement of the trench is beneficial to the uniform distribution of the current, so that the brightness of light emission and reliability of a chip is improved.