Bidirectional Wafer-Level Light Coupling via Diffractive Grating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional 3D chip stacking using unidirectional signal routing limits the minimization of physical dimensions in semiconductor structures.
Innovation Solution
The implementation of bidirectional diffractive grating couplers (DGCs) and through-silicon vias (TSVs) enables bidirectional light coupling within semiconductor structures, allowing for optical signal transfer between the frontside and backside of the structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If unidirectional signal routing is used in traditional 3D chip stacking, then the structure is simpler to implement, but the physical dimensions cannot be minimized
Solution Approach 1:
The patent introduces bidirectional signal routing that operates in multiple directions (frontside-to-backside and backside-to-frontside) rather than traditional unidirectional routing. This multi-directional approach utilizes the vertical dimension more effectively, allowing signals to traverse the stacked structure in both directions and thereby minimizing the overall physical footprint of the semiconductor device.
Solution Approach 2:
The diffractive grating couplers are designed to support multiple functions: they enable both frontside-to-backside and backside-to-frontside optical coupling, and can route signals through different paths (direct TSV routing and grating-mediated routing). This multi-functionality allows a single coupling mechanism to serve multiple signal transmission needs, reducing the overall device complexity despite the enhanced routing capabilities.
2Adaptability or versatility
If bidirectional diffractive grating couplers are implemented, then light-coupling features and channel density are increased, but the manufacturing process becomes more complex
Solution Approach 1:
The bidirectional coupling function is achieved by segmenting the coupling mechanism into two separate diffractive grating couplers: a first DGC for frontside-to-backside coupling and a second DGC for backside-to-frontside coupling. Each grating is independently designed and fabricated, which simplifies the manufacturing process compared to creating a single complex bidirectional coupler, while still achieving the desired multi-directional light coupling capability.
Solution Approach 2:
The patent introduces an intermediary layer or structure that facilitates the bidirectional coupling between the frontside and backside of the semiconductor stack. This intermediary mechanism (the diffractive grating structure) acts as a mediator that enables optical signals to transition between directions without requiring complex direct bidirectional interfaces, thereby simplifying the overall fabrication process while enhancing light-coupling flexibility.
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 solution increases light-coupling features in compact semiconductor structures, enhancing channel density and providing greater flexibility in chip design.
Implementation Method 1
bidirectional diffractive grating couplers (DGCs) and through-silicon vias (TSVs) that allow for bidirectional light coupling within a semiconductor structure
Data Source
AI summary
A semiconductor structure with bidirectional wafer-level light coupling is provided. In one embodiment, the semiconductor structure includes a bidirectional diffractive grating coupler, where the bidirectional diffractive grating coupler includes a first diffractive grating coupler, a planar waveguide, and a second diffractive grating coupler, a first optical through-silicon via cladding coupled to the first diffractive grating coupler, and a second optical through-silicon via cladding coupled to the first diffractive grating coupler.