Multi-chip Module Grating Couplers for Optical Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electronic connections between integrated circuit chips in multi-chip modules (MCMs) cannot support high bandwidth communication, which is achievable with optoelectronic devices like grating couplers and optical waveguides.
Innovation Solution
The development of multi-chip modules that allow for chip-to-chip transmission of light signals by vertically aligning grating couplers on different components, such as integrated circuit chips and interposers, enabling light signal transmission between optical waveguides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electronic connections are used between integrated circuit chips in multi-chip modules, then device complexity is reduced and ease of manufacture is improved, but bandwidth communication capability deteriorates
Solution Approach 1:
The patent replaces electronic signal transmission (electrical field) with optical signal transmission (electromagnetic field). Grating couplers convert electrical signals to optical signals and vice versa, enabling high-bandwidth communication while maintaining ease of manufacturing through standard semiconductor fabrication processes. This substitution resolves the contradiction by achieving high bandwidth without compromising manufacturability.
Solution Approach 2:
The patent changes the transmission medium parameter from electrical conductors to optical waveguides. By integrating optical waveguides and grating couplers into the chip architecture, the system achieves higher bandwidth communication capability while maintaining compatibility with existing manufacturing techniques, thus resolving the trade-off between ease of manufacture and communication performance.
2Productivity
If optoelectronic devices like grating couplers and optical waveguides are used for high bandwidth communication, then bandwidth communication capability is improved, but device complexity increases
Solution Approach 1:
The patent merges optical components (grating couplers, waveguides) with electronic circuit components into a unified hybrid chip architecture. This integration allows optical signal transmission for high bandwidth communication while sharing common fabrication processes and packaging techniques with electronic components, thereby reducing overall device complexity despite the addition of optoelectronic functionality.
Solution Approach 2:
The grating couplers serve multiple functions: they act as optical-to-electrical and electrical-to-optical converters, enable high-bandwidth communication, and can be integrated with existing electronic circuitry. This multi-functionality reduces the need for separate dedicated optical modules, thereby managing device complexity while achieving high bandwidth capability.
3Productivity
If grating couplers are vertically aligned for light signal transmission between chips, then bandwidth communication capability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs preliminary alignment actions during the fabrication process, such as forming alignment marks and using self-aligned fabrication techniques. Grating couplers are positioned with predetermined geometries that facilitate automatic alignment during chip stacking, reducing the actual assembly precision requirements while maintaining high bandwidth communication capability through vertical light signal transmission.
Solution Approach 2:
The patent introduces intermediary alignment structures (alignment marks, reference features) that mediate the alignment process between grating couplers on different chips. These intermediaries enable precise vertical alignment during assembly without requiring extremely tight tolerances in the final positioning, thus achieving high bandwidth communication while managing manufacturing precision requirements.
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
Enables high bandwidth communication between integrated circuit chips by facilitating the transmission of light signals through vertically aligned grating couplers, overcoming the limitations of existing electronic connections.
Implementation Method 1
a grating coupler can receive a light signal from an off-chip optical fiber or a light source
Implementation Method 2
the light signal can be transmitted to an optical waveguide, which, in turn, transmits the light signal
Implementation Method 3
The photodetector can convert the light signal into an electronic signal for further processing
Data Source
AI summary
Disclosed are multi-chip modules (MCMs) that allow for chip-to-chip transmission of light signals. The MCMs can incorporate at least two components, which are attached (e.g., by interconnects). For example, in one MCM disclosed herein, the two components can be an integrated circuit chip and an interposer to which the integrated circuit chip and one or more additional integrated circuit chips are attached by interconnects. In another MCM disclosed herein, the two components can be two integrated circuit chips that are stacked and attached to each other by interconnects. In either case, the two components can each have a waveguide and a grating coupler coupled to one end of the waveguide. The grating couplers on the different components can be approximately vertically aligned, thereby allowing light signals to be transmitted between the waveguides on those different components. Also, disclosed herein are methods of forming such MCMs.