Rib Waveguide Etch Stop Structure for Precise Photonic Patterning
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Solution Overview
Problem
As integrated circuits become smaller and faster, electrical signal delays due to capacitance, inductance, or resistance become a design concern, necessitating the use of optical signals for data transmission.
Innovation Solution
The development of a photonic device with rib waveguides and etch stop layers to prevent mask collapse during patterning, utilizing rib trenches and etch stop layers to protect underlying layers during etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching processes are used without etch stop layers, then the patterning process is simpler, but mask collapse occurs during etching
Solution Approach 1:
An etch stop layer is deposited on the substrate before the rib waveguide formation. This preliminary layer prevents mask collapse during the rib trench etching process by providing mechanical support to the mask structure, thereby enabling precise patterning without requiring complex mask support structures.
Solution Approach 2:
The etch stop layer acts as an intermediary between the substrate and the rib waveguide structure. It provides mechanical support during etching to prevent mask collapse, and is later selectively removed to release the rib waveguide, thus mediating between the need for structural support and the need for waveguide release.
2Productivity
If rib waveguides are formed without etch stop layers, then the fabrication process is faster, but mask collapse prevents precise patterning
Solution Approach 1:
The etch stop layer is deposited in advance before rib waveguide formation. This preliminary action provides the necessary mechanical support during etching to prevent mask collapse, enabling precise patterning to be achieved without requiring multiple support layers or complex fabrication procedures.
3Manufacturing precision
If etch stop layers are added to prevent mask collapse, then patterning precision is improved, but the number of fabrication steps increases
Solution Approach 1:
The etch stop layer is deposited as a preliminary step before rib waveguide formation. This single preliminary layer provides sufficient mechanical support during etching to prevent mask collapse, achieving precise patterning without requiring multiple support layers or complex fabrication procedures.
Solution Approach 2:
The etch stop layer serves as an intermediary that is temporarily present during fabrication to enable precise patterning, then selectively removed to complete the device. This mediator approach adds only one essential step while avoiding the need for multiple complex support structures.
4Manufacturing precision
If multiple support layers are used to prevent mask collapse, then patterning precision is maintained, but fabrication time increases
Solution Approach 1:
A single etch stop layer is deposited in advance to provide the necessary mechanical support during etching. This single preliminary layer is sufficient to prevent mask collapse, eliminating the need for multiple support layers and reducing fabrication steps compared to conventional approaches.
Data Source
AI summary
A photonic device structure and method of fabricating the same. The structure includes a substrate that has a topside oxide layer and a silicon layer that is formed on the topside oxide layer. The structure further includes a rib waveguide component formed in the silicon layer and that includes contact holes. The contact holes include a contact hole depth, and a contact hole trench that is formed in the silicon layer and which has a first sidewall, a second sidewall, and a bottom surface. The contact hole further includes a contact etch stop layer formed in the contact hole trench.