Semiconductor Optical Waveguides on Opposing Insulating Film Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor devices with optical waveguides formed on a single surface of an insulating film often suffer from poor characteristics due to material stress, cracking, and mismatched processing conditions, especially when the waveguides have different thicknesses and materials, leading to suboptimal performance.
Innovation Solution
The semiconductor device features a first optical waveguide on one surface and a second optical waveguide on an opposing surface of the insulating film, with the second waveguide overlapping only one end of the first waveguide in plan view, allowing for separate formation and reduced stress, thereby improving manufacturing efficiency and device characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If both optical waveguides are formed on the same surface of the insulating film, then the device structure is simplified, but cracks may form in the first optical waveguide due to material stress from the second optical waveguide
Solution Approach 1:
The patent transitions from forming both waveguides on the same surface (2D arrangement) to forming waveguides on opposite surfaces of the insulating film (3D arrangement). This dimensional change eliminates the stress-induced cracking problem while maintaining a compact device structure, as the waveguides are separated in the vertical dimension rather than occupying the same planar space.
2Ease of manufacture
If both optical waveguides are formed under the same processing condition, then the manufacturing process is simplified, but desired characteristics cannot be obtained when waveguides have different thicknesses
Solution Approach 1:
The patent divides the waveguide formation process into separate stages: first waveguide formation on the initial surface, then insulating film deposition, and finally second waveguide formation on the opposite surface. This segmentation allows each waveguide to be optimized with different processing conditions, materials, and thicknesses independently, achieving precise control over waveguide characteristics while maintaining manufacturing feasibility.
3Reliability
If the second optical waveguide covers the end portion of the first optical waveguide on the same surface, then light can propagate between waveguides, but the overlapping configuration causes stress and cracking issues
Solution Approach 1:
The patent resolves the conflict between optical coupling and stress prevention by moving the overlapping configuration from the same surface (2D overlap) to opposite surfaces (3D overlap through the insulating film). This allows evanescent field coupling to occur through the insulating film while physically separating the waveguides to eliminate stress-induced cracking, achieving both optical functionality and structural integrity.
Data Source
AI summary
A semiconductor device includes a first insulating film, a first optical waveguide and a second optical waveguide. The first insulating film has a first surface and a second surface opposite to the first surface. The first optical waveguide is formed on the first surface of the first insulating film. The second optical waveguide is formed on the second surface of the first insulating film. The second optical waveguide, in plan view, overlaps with an end portion of the first optical waveguide without overlapping with another end portion of the first optical waveguide.