Nitride Semiconductor Laser Cleavage Yield via Island Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nitride semiconductor laser elements face challenges in maintaining stable current and voltage characteristics due to dislocations and crystal defects, leading to issues like low start-up voltage and reduced service life, which affect the yield and quality of the manufacturing process.
Innovation Solution
A nitride semiconductor laser element is manufactured with a laminate structure that includes a first conductivity type nitride semiconductor layer, an active layer, and a second conductivity type nitride semiconductor layer, featuring an exposed region and an island layer to guide cleavage and reduce the impact of dislocations and crystal defects, thereby improving the cleavage yield and maintaining consistent quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If cleavage is performed to form cavity end faces, then the laser element structure is completed, but dislocation density and crystal defects cause cleavage plane distortion and reduce manufacturing precision
Solution Approach 1:
An intermediate layer is introduced between the nitride semiconductor layer and the substrate. This intermediate layer serves as a mediator that absorbs dislocations and crystal defects, preventing them from propagating to the cleavage plane. The intermediate layer has different mechanical and thermal properties that facilitate clean cleavage while maintaining structural integrity.
Solution Approach 2:
The harmful dislocation and defect-prone substrate region is separated from the active nitride semiconductor layer by removing or isolating the defective region. The intermediate layer effectively extracts the harmful effects from the cleavage path, allowing clean separation without carrying over substrate defects.
2Ease of manufacture
If electrodes are formed on the semiconductor layer, then electrical connections are established, but electrode drooping occurs during division and adversely affects characteristics
Solution Approach 1:
The intermediate layer is formed before electrode deposition, creating a stable foundation that prevents electrode drooping during subsequent processing. This preliminary structural preparation ensures that electrodes maintain their intended positions throughout manufacturing operations.
Solution Approach 2:
The mechanical and thermal parameters of the intermediate layer are optimized to match the nitride semiconductor layer while providing structural support. By adjusting the intermediate layer's properties (composition, thickness, crystalline structure), electrode stability is enhanced without compromising electrical performance.
3Manufacturing precision
If primary cleavage is performed with high accuracy to form smooth cavity end faces, then light emission quality is improved, but the complexity of the manufacturing process increases
Solution Approach 1:
The intermediate layer acts as a mediator that simplifies the cleavage process. Instead of directly cleaving through the entire structure from the substrate, the intermediate layer provides a predetermined cleavage plane that is easier to control, reducing the complexity of achieving high-precision cavity end faces.
Data Source
AI summary
A nitride semiconductor laser element includes a laminate. The laminate includes on a substrate a first conductivity type nitride semiconductor layer, an active layer, and a second conductivity type nitride semiconductor layer, and constitutes a cavity resonator. The laminate includes an element region, an exposed region and an island layer. The element region is a region in which the laser element is formed. The exposed region is a region in which at least the first conductivity type nitride semiconductor layer is exposed on both sides of the element region in the cavity direction, and which is provided continuously in a cavity resonating direction of the laser element. The island layer is separated from the element region by the exposed region, and that is disposed in a corner of the nitride semiconductor laser element.