Semiconductor Waveguide Signal Loss Reduction

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Solution Overview

Problem

Semiconductor devices with silicon nitride waveguides face significant signal loss and noise introduction due to longer vias between conductive structures and modulator structures, limiting the efficient propagation of optical signals within the 1,500 to 1,600 nanometer wavelength range.

Innovation Solution

The semiconductor device incorporates a silicon nitride waveguide in a first dielectric layer over a substrate, with a semiconductor waveguide in a second dielectric layer, where the silicon nitride waveguide is annealed to reduce hydrogen content, and the modulator structure is positioned closer to the conductive structure, reducing signal loss and noise introduction by minimizing the distance between them.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the silicon nitride waveguide is placed over the modulator structure, then the optical signal can be propagated, but the via distance between conductive structure and modulator structure increases causing signal loss and noise

Engineering Contradiction:

Improvesignal qualityVSAvoidsignal loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent repositions the modulator structure to be laterally adjacent to the silicon nitride waveguide rather than vertically underneath it. This dimensional rearrangement allows the conductive structure to connect directly to the modulator without requiring a long via through multiple dielectric layers, thereby reducing signal loss and noise while maintaining optical signal propagation capability.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If the via distance between conductive structure and modulator structure is reduced, then signal loss and noise are minimized, but the structural configuration becomes more complex

Engineering Contradiction:

Improvesignal qualityVSAvoidstructural configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

By transitioning from a vertical stacking configuration to a lateral adjacent configuration, the patent achieves shorter via distances without significantly increasing manufacturing complexity. The modulator structure is positioned in the second dielectric layer adjacent to the waveguide, allowing direct connection with minimal additional process steps.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 configuration significantly reduces signal loss and noise, enabling the efficient propagation of optical signals within the 1,500 to 1,600 nanometer wavelength range, improving the performance of photonic devices like silicon-based photonic ICs.

Implementation Method 1

the silicon nitride waveguide is annealed to reduce hydrogen content

Methodology Applied

Scientific EffectAnnealing: Annealing

Implementation Method 2

the optical signal is propagated via at least one of the semiconductor waveguide or the silicon nitride waveguide

Methodology Applied

Scientific EffectOptical signal propagation: Waveguide (optics)

Data Source

PatentUS11256114B2Semiconductor device and method of making

Publication Date: 2022.02.22 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A semiconductor device is provided. The semiconductor device includes a silicon nitride waveguide in a first dielectric layer over a substrate. The semiconductor device includes a semiconductor waveguide in a second dielectric layer over the first dielectric layer. The first dielectric layer including the silicon nitride waveguide is between the second dielectric layer including the semiconductor waveguide and the substrate.