Ridge Waveguide Semiconductor Laser Electrode Separation
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Solution Overview
Problem
The manufacturing yield of ridge waveguide type semiconductor integrated elements is compromised due to incomplete removal of electrode layers caused by shadow effects during dry etching, leading to decreased separation resistance and response speed of semiconductor lasers.
Innovation Solution
A method involving the formation of a concave/convex structure with insulating material extending between electrode areas, embedding this structure before electrode layer deposition, and using oriented dry etching to ensure complete electrode removal, preventing shadowing and ensuring perfect electrical separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electrode material is directly evaporation-deposited onto the passivation film, then electrode formation is simplified, but incomplete electrode removal occurs in shadow areas during dry etching
Solution Approach 1:
The patent applies preliminary action by forming the concave/convex structure on the passivation film before electrode material deposition. This pre-formed structure guides the electrode material to specific areas, ensuring that during subsequent dry etching, the electrode material can be completely removed from non-electrode areas without leaving residues in shadow regions. The structure is created by selective etching of the passivation film to form patterns that prevent shadowing effects.
Solution Approach 2:
The patent uses the concave/convex structure as an intermediary element between the passivation film and the electrode material. This intermediate structure serves as a template that controls where electrode material is deposited and ensures complete removal from areas that should not contain electrodes. The structure mediates the interaction between the deposition and etching processes, eliminating the shadow effect problem.
2Manufacturing precision
If dry etching with orientation is used to form electrode patterns, then precise electrode positioning is achieved, but shadow effects cause electrode layer remnants to remain
Solution Approach 1:
The patent applies preliminary action by pre-forming the concave/convex structure on the passivation film before electrode material deposition. This pre-formed structure guides the electrode material to specific areas, ensuring that during subsequent dry etching, the electrode material can be completely removed from non-electrode areas without leaving residues in shadow regions. The structure is created by selective etching of the passivation film to form patterns that prevent shadowing effects.
Solution Approach 2:
The patent introduces a vertical dimension by forming concave and convex structures on the passivation film surface. This three-dimensional structure changes the topology of the surface, creating slopes and angles that allow the ion beam to access areas that would otherwise be in shadow. By adding this vertical dimension, the patent eliminates the shadow effect while maintaining precise electrode positioning through oriented dry etching.
3Area of stationary object
If electrodes are formed on thick passivation film areas, then electrode coverage is improved, but separation resistance between electrodes decreases
Solution Approach 1:
The patent applies local quality by creating a non-uniform passivation film structure with concave and convex areas. The electrode material is deposited on the convex areas where electrodes are desired, while the concave areas serve as separation regions. This local differentiation ensures that electrodes are properly formed on the substrate while maintaining high separation resistance between adjacent electrodes through the concave regions that prevent electrical coupling.
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 allows for the electrical and perfect separation of electrodes, enhancing the manufacturing yield and response speed of semiconductor lasers by preventing electrode layer remnants and ensuring consistent electrode formation.
Implementation Method 1
a portion where the thickness of passivation film 68 changes becomes a shadow of an ion beam and there is a case where an electrode layer 66 formed in such a portion is not perfectly removed
Implementation Method 2
an electrode material (for example, Au) is evaporation-deposited on the passivation film
Data Source
AI summary
A semiconductor element and a manufacturing method of the semiconductor element are provided. A ridge waveguide type semiconductor integrated element includes: an electrode of an EA portion and an electrode of an LD portion which are arranged so as to be away from each other; a contact layer of the EA portion and a contact layer of the LD portion which are arranged so as to be away from each other and in each of which the electrode is formed on an upper surface and an edge of at least a part of the upper surface is set to the same electric potential as that of the electrode; a passivation film as an insulative concave/convex structure extending from an edge of one of the two contact layers to an edge of the other contact layer; and a polyimide resin for embedding the passivation film.