Optical Semiconductor Protrusion Alignment for Compact Photonic Assembly
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Solution Overview
Problem
Existing optical integrated devices face challenges in securing alignment accuracy between optical semiconductor devices and functional devices due to variations in passivation film thickness and peeling, leading to reduced light coupling efficiency, and suffer from increased device size due to structural requirements for alignment.
Innovation Solution
The optical semiconductor device features a substrate with first and second protrusions having a laminate structure with exposed semiconductor layers, where the second protrusions serve as alignment members, and a manufacturing method involving etch stop layers and current inhibition layers to ensure precise alignment and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a passivation film is provided at the leading end of the protrusion for alignment, then alignment in the layering direction is achieved, but the passivation film thickness variation and peeling occur leading to reduced alignment accuracy
Solution Approach 1:
The invention extracts the alignment function from the passivation film and relocates it to the end face of the protrusion itself. By making the protrusion end face the alignment reference surface, the patent eliminates dependence on the passivation film's thickness and adhesion properties, thereby resolving the reliability issue while maintaining alignment accuracy.
Solution Approach 2:
Instead of using a separate passivation film layer for alignment, the invention inverts the approach by using the structural element (protrusion) itself as the alignment reference. This inversion eliminates the intermediate layer that causes reliability problems while achieving the same alignment function.
2Manufacturing precision
If salient portions are housed in depressed portions for alignment, then alignment in the layering direction is achieved, but the device size increases
Solution Approach 1:
The invention extracts the alignment function from the depressed portion structure and implements it directly on the protrusion end face. This eliminates the need for large depressed portions that house salient portions, thereby reducing device size while maintaining alignment accuracy through the exposed semiconductor layer at the protrusion tip.
Solution Approach 2:
Instead of creating negative space (depressed portions) for alignment, the invention uses the positive protrusion structure itself as the alignment reference. This inversion eliminates the need for large housing spaces, significantly reducing device volume while achieving precise alignment.
Data Source
AI summary
An optical semiconductor device includes: a substrate; a first protrusion protruding from the substrate in a first direction and including a first mesa having a laminate structure in which a plurality of semiconductor layers are layered on the substrate in the first direction, the first mesa including an active layer as one of the semiconductor layers; and a second protrusion protruding from the substrate in the first direction at a distance from the first protrusion in a second direction intersecting with the first direction, the second protrusion having a same laminate structure as the laminate structure of the first mesa, wherein one of the plurality of semiconductor layers is exposed at an end portion of the second protrusion in the first direction.