Silicon Waveguide Fabrication on Non-SOI Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high cost and complexity of producing silicon photonic devices, particularly crystalline silicon waveguides, on silicon-on-insulator (SOI) substrates hinder their integration with electronic devices, as they require separate manufacturing processes on different substrates, increasing costs and difficulty.
Innovation Solution
A method to produce silicon waveguides on non-SOI substrates by forming a ridge structure with high aspect ratio, melting and reshaping it using laser illumination to create a structure with a broad upper and narrow lower part, and then oxidizing the narrow lower part to form a silicon waveguide, allowing for integration with electronic devices on a common silicon substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon photonic devices are produced on SOI substrate, then the device performance is improved, but the production cost and process complexity increase
Solution Approach 1:
The patent replaces expensive SOI substrates with inexpensive common silicon substrates. The method uses a disposable sacrificial oxide layer that is grown and then selectively removed to create the waveguide structure, eliminating the need for costly SOI substrate fabrication while achieving the same photonic device performance
Solution Approach 2:
The patent changes the physical and chemical parameters of the silicon substrate by growing a thick oxide layer that is subsequently selectively removed. This parameter transformation (adding oxide then removing it selectively) creates the waveguide structure on common silicon substrates, achieving SOI-like performance without SOI substrate complexity
2Manufacturing precision
If silicon photonic devices are produced on SOI substrate, then the device quality is improved, but the integration with electronic devices becomes more difficult
Solution Approach 1:
The patent merges the fabrication processes for electronic devices and photonic devices by using the same common silicon substrate for both. The selective oxidation and etching methods used to create photonic waveguides are compatible with standard CMOS electronic device fabrication, allowing both device types to be manufactured together on the same substrate
Solution Approach 2:
The patent makes the common silicon substrate universal for both electronic and photonic device fabrication. The process methodology using selective oxidation and etching serves multiple functions: creating waveguide structures, defining device regions, and maintaining compatibility with electronic device manufacturing, thereby enabling seamless integration
3Ease of manufacture
If common silicon substrate is used instead of SOI substrate, then the production cost is reduced, but the ability to produce high-quality crystalline silicon waveguides is compromised
Solution Approach 1:
The patent replaces the mechanical/physical SOI substrate structure (silicon-silicon dioxide-silicon layers) with a chemical process approach. By using selective oxidation to grow oxide and then selective etching to remove it, the method creates the equivalent waveguide structure on common silicon substrates, achieving high-quality crystalline waveguides without the complex SOI substrate manufacturing
4Reliability
If separate substrates are used for electronic devices and photonic devices, then each device type can be optimized, but the overall system complexity and integration cost increase
Solution Approach 1:
The patent merges separate electronic and photonic device fabrication onto a single common silicon substrate. The process allows different device regions to be optimized independently while sharing the same substrate and compatible fabrication steps, reducing system complexity and enabling direct integration without additional assembly steps
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 method reduces production costs and simplifies the integration of silicon photonic devices with electronic devices, enabling them to be produced on the same substrate, thus lowering integration costs and complexity, and facilitating optical connections between ICs and semiconductor devices.
Implementation Method 1
melting and reshaping the ridge structure by laser illumination
Implementation Method 2
melting and reshaping the ridge structure by laser illumination
Implementation Method 3
oxidizing the narrow lower part of the structure and periphery part of the broad upper part of the structure to form a silicon waveguide
Data Source
AI summary
The present invention relates to a method for producing silicon waveguides on non-SOI substrate (non-silicon-on-insulator substrate), and particularly relates to a method for producing silicon waveguides on silicon substrate with a laser. This method includes the following steps: (1) forming a ridge structure with high aspect ratio on a non-SOI substrate; (2) melting and reshaping the ridge structure by laser illumination for forming a structure having broad upper part and narrow lower part; and (3) oxidizing the structure having broad upper part and narrow lower part to form a silicon waveguide.