Optical Semiconductor Protrusion Geometry for Precise Light Coupling
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Solution Overview
Problem
In optical integrated devices, low alignment accuracy between the optical semiconductor device and the optical functional device leads to reduced coupling efficiency of light, primarily due to inaccuracies in forming protrusions that act as alignment members.
Innovation Solution
The optical semiconductor device features a substrate with accurately formed protrusions, including a first mesa with a laminate structure containing an active layer and second protrusions with polygonal-shaped end faces, non-parallel to specific virtual lines, to enhance alignment accuracy. The manufacturing method involves forming mesas, filling spaces with current inhibition layers, and using etching with a mask to create these protrusions, ensuring precise alignment and coupling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If protrusions are formed as alignment members between optical semiconductor device and optical functional device, then alignment accuracy is improved, but manufacturing precision deteriorates due to difficulty in forming protrusions with sufficient accuracy
Solution Approach 1:
The end face of the second protrusion is given an asymmetric polygonal shape where each side is intentionally non-parallel to the <0-11> direction. This asymmetric configuration prevents symmetric etching artifacts and ensures that the protrusion maintains its intended geometry with high precision during the etching process, thereby improving manufacturing precision while maintaining alignment accuracy
Solution Approach 2:
The invention changes the directional parameters of the protrusion end face by specifying that each side should be non-parallel to the <0-11> direction. This parameter modification optimizes the etching behavior and prevents formation artifacts, thereby improving the manufacturing precision of the protrusion structure
2Measurement precision
If protrusions are formed with higher accuracy to ensure alignment, then alignment accuracy is improved, but device complexity increases due to additional processing requirements
Solution Approach 1:
By optimizing the directional parameters of the mask and etching process (making sides non-parallel to <0-11>), the invention achieves high protrusion accuracy through parameter optimization rather than adding complex processing steps, thereby improving alignment accuracy without significantly increasing device complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures more reliable alignment accuracy between the optical semiconductor device and the optical functional device, thereby maintaining high coupling efficiency of light and reducing manufacturing costs by eliminating unnecessary processing steps.
Implementation Method 1
forming a plurality of mesas protruding from the substrate at a plurality of locations separated in a second direction intersecting with the first direction by partially removing the laminate structure on an opposite side of the substrate
Implementation Method 2
forming the second mesa by performing etching using a mask, and in planar view from an opposite direction of the first direction, the mask has a polygonal shape with each side being non-parallel to a virtual line extending in <0-11> direction
Data Source
AI summary
An optical semiconductor device includes: a substrate having a (100) face as a surface; 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 surface 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 position distance from the first protrusion in a second direction intersecting with the first direction, and the second protrusion having a laminate structure in which a plurality of semiconductor layers are layered on the surface in the first direction. An end face in the first direction of the second protrusion has a substantially polygonal shape, and each side of the end face is non-parallel to a virtual line extending in [0-11] direction.