Semiconductor Laser Ridge Structure for Uniform Transparent Electrode Contact
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Solution Overview
Problem
Existing semiconductor laser technologies face challenges in forming a transparent conductive layer that ensures a wide contact area with the semiconductor layer, leading to potential voltage rise and uneven current injection, and struggle with achieving sufficient light trapping in the lateral direction.
Innovation Solution
A semiconductor device configuration featuring a first semiconductor layer with a stripe-shaped ridge, a second semiconductor layer, and a transparent conductive layer formed of transparent conductive material, where the transparent conductive layer has a uniform thickness and specific width ratios, ensuring a wide contact area and uniform current injection, and includes intermediate layers for improved adhesion with electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the transparent conductive layer is formed using conventional process flows with resist removal, then the manufacturing process is simple, but the contact area between the transparent conductive layer and semiconductor layer is reduced, causing voltage rise and uneven current injection
Solution Approach 1:
The patent applies preliminary action by forming the transparent conductive layer over the entire ridge surface before any patterning or resist removal steps. This ensures maximum contact area is established early in the process, preventing subsequent reduction of contact area that would occur with conventional resist-based patterning methods.
Solution Approach 2:
The patent extracts the resist removal step from the conventional process flow. By eliminating the resist application and removal steps, the transparent conductive layer remains continuously deposited over the entire ridge surface without gaps or reduced contact areas, thereby maintaining both manufacturing simplicity and electrical connection reliability.
2Illumination intensity
If the transparent conductive layer is etched into waveguide shape, then the light trapping effect in lateral direction is improved, but the contact area with semiconductor layer is reduced, causing voltage rise
Solution Approach 1:
The patent applies dimensionality change by maintaining the transparent conductive layer in its original planar form over the ridge surface, rather than etching it into a three-dimensional waveguide shape. This preserves the two-dimensional contact area with the semiconductor layer, ensuring stable electrical connection while still allowing light trapping through the ridge structure itself.
Solution Approach 2:
The patent makes the ridge structure itself serve multiple functions: it provides both the current blocking structure for electrical confinement and the waveguide shape for optical confinement. This eliminates the need for separate etching of the transparent conductive layer into waveguide shape, thereby maintaining electrical connection stability while achieving light trapping effects.
3Device complexity
If the contact area between transparent conductive layer and semiconductor layer is reduced, then the device structure is simplified, but voltage rise and uneven current injection occur
Solution Approach 1:
The patent applies homogeneity by ensuring the transparent conductive layer is uniformly deposited across the entire ridge surface, creating a homogeneous contact area with the semiconductor layer. This uniform contact distribution ensures even current injection throughout the active region, preventing localized hot spots or uneven lasing modes that would result from reduced or non-uniform contact areas.
Data Source
AI summary
To provide a semiconductor device, a semiconductor laser, and a method of producing a semiconductor device that are capable of sufficiently ensuring electrical connection between a transparent conductive layer and a semiconductor layer. [Solving Means] A semiconductor device according to the present technology includes: a first semiconductor layer; a second semiconductor layer; an active layer; and a transparent conductive layer. The first semiconductor layer has a first conductivity type, a stripe-shaped ridge being formed on a surface of the first semiconductor layer. A second width is not less than 0.99 and not more than 1.0 times a first width, a third width is not less than 0.96 and not more than 1.0 times the second width, and the transparent conductive layer has a uniform thickness within a range of not less than 90% and not more than 110% in a range of the third width, the first width being a width in a direction perpendicular to an extending direction of the ridge on a surface of the ridge on which the transparent conductive layer is formed, the second width being a width in the direction on a surface of the transparent conductive layer on a side of the ridge, the third width being a width in the direction on a surface opposite to the ridge of the transparent conductive layer.