Integrated Grating and Edge Couplers With Shared Etch Flow
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Solution Overview
Problem
The separate fabrication of grating couplers and edge couplers on a photonic integrated circuit (PIC) is time-consuming and costly, making it impractical to integrate both types on the same chip due to the complexity and number of photolithography, patterning, and etching steps involved.
Innovation Solution
A method is introduced to integrate the fabrication of grating couplers and edge couplers on the same substrate by performing deep trench etches and multiple etching steps using masks, reducing the number of photolithography and etching processes, and incorporating multiple trench depths and tapered structures in both couplers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate fabrication processes are used for grating couplers and edge couplers, then each coupler type can be optimized for its specific performance, but the production time and cost increase significantly
Solution Approach 1:
The patent combines the fabrication of grating couplers and edge couplers into a single integrated process flow. Multiple coupler types are formed simultaneously on the same substrate using shared etching steps and common process sequences, eliminating the need for separate fabrication lines and reducing overall production time while maintaining the distinct performance characteristics of each coupler type.
Solution Approach 2:
The fabrication process is designed to be universal, accommodating both grating coupler and edge coupler formation within the same process sequence. The method uses configurable masks and adjustable etching parameters that can be tuned to produce different coupler geometries and depths, allowing a single process to serve multiple coupler fabrication needs.
2Reliability
If separate fabrication processes are used for grating couplers and edge couplers, then each coupler type can be optimized for its specific performance, but the manufacturing complexity increases
Solution Approach 1:
The patent merges the fabrication sequences for grating couplers and edge couplers into a unified process. By combining mask deposition, patterning, and etching steps that are common to both coupler types, the overall process complexity is reduced despite the diversity of coupler geometries being produced.
Solution Approach 2:
The method applies local quality by using region-specific mask patterns and selective etching parameters within the unified process. Different areas of the substrate receive tailored processing conditions (such as varying etch depths, mask configurations, and patterning densities) to produce the appropriate coupler type for each location, while still following the same overall process flow.
3Reliability
If separate fabrication processes are used for grating couplers and edge couplers, then each coupler type can be optimized for its specific performance, but the production cost increases
Solution Approach 1:
The patent combines fabrication operations to reduce the total number of process steps required. By integrating grating coupler and edge coupler formation into a single process flow with shared equipment usage and consolidated process chambers, the patent eliminates redundant operations and reduces per-unit manufacturing costs.
Solution Approach 2:
The fabrication process is designed as a universal platform that can produce multiple coupler types using the same equipment and material layers. This multi-functionality allows for better equipment utilization, reduced material waste, and streamlined production planning, all of which contribute to lower overall manufacturing costs.
Data Source
AI summary
Some embodiments relate to an integrated chip (IC) including a handle substrate; a semiconductor layer comprising a grating coupler region and an edge coupler region; an insulative layer between the handle substrate and the semiconductor layer; a grating coupler in the grating coupler region comprising a plurality of trenches arranged in the semiconductor layer; and an edge coupler in the edge coupler region of the semiconductor layer including: a base structure having an end proximate to an edge of the insulative layer, and tapered sidewalls extending laterally from the end; and an upper structure extending over the base structure, the upper structure having an end proximate to the edge of the insulative layer, and tapered sidewalls extending laterally from the end between the tapered sidewalls of the base structure; where the handle substrate continuously extends from directly beneath the plurality of trenches to directly beneath the upper structure.