Silicon Photonic Waveguide Heaters With Dielectric Void Isolation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing silicon photonic integrated circuits (SiPh PICs) face challenges in achieving efficient heater element power usage due to inadequate thermal isolation, which is crucial for applications like Optical Compute Interconnect (OCI) and co-packaged optics (CPO), necessitating improved heater element efficiency.

Innovation Solution

The integration of voids, including overvoids, side-voids, and undervoids, within the dielectric material surrounding heater elements in SiPh PICs to enhance thermal isolation, reducing heat conduction and improving heater efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If heater elements are fabricated near optical waveguides to modulate signal phasing, then optical modulation function is achieved, but thermal conduction to substrate reduces heater power efficiency

Engineering Contradiction:

Improveheater power efficiencyVSAvoidthermal conduction loss

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

A dielectric layer is introduced as an intermediary between the heater element and the silicon substrate. This dielectric layer acts as a thermal barrier that reduces direct thermal conduction from the heater to the substrate, thereby improving heater power efficiency while allowing the heater to remain positioned near the optical waveguide for effective signal phasing modulation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a thin dielectric film structure to provide thermal isolation. This thin film serves as a flexible thermal barrier that prevents excessive heat transfer to the substrate while maintaining the structural integrity and optical properties of the integrated circuit.

Inventive Principle:

Principle #30Flexible shells and thin films

2Productivity

If heater elements are positioned close to waveguides for efficient modulation, then modulation efficiency improves, but thermal isolation becomes insufficient causing higher power consumption

Engineering Contradiction:

Improvemodulation efficiencyVSAvoidheater power consumption

Core Design Contradiction:

ProductivityVSUse of energy by stationary object

Solution Approach 1:

The dielectric layer serves as a mediator that enables close positioning of the heater element to the waveguide for efficient modulation while simultaneously providing thermal isolation to reduce power consumption. This intermediary structure resolves the contradiction by decoupling the thermal and optical interaction paths.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If conventional dielectric material is used without voids, then structural simplicity is maintained, but thermal conduction increases reducing heater efficiency

Engineering Contradiction:

Improvedielectric structure complexityVSAvoidheater efficiency

Core Design Contradiction:

Device complexityVSUse of energy by moving object

Solution Approach 1:

The dielectric material is designed with a porous structure containing voids. These voids act as thermal barriers that interrupt heat conduction pathways from the heater element to the substrate. The porous structure increases thermal isolation and improves heater efficiency while adding only moderate structural complexity that can be integrated during standard fabrication processes.

Inventive Principle:

Principle #31Porous materials

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

The implementation of voids significantly enhances heater element efficiency by minimizing thermal conduction, allowing for lower power consumption and improved modulation of optical properties in SiPh PICs.

Implementation Method 1

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentUS20250306405A1Silicon photonic integrated circuits with enhanced thermal isolation of heater elements

Publication Date: 2025.10.02 INTEL CORP

AI summary

Silicon photonic (SiPh) integrated circuit (PIC) comprising an optical waveguide heater element is thermally isolated by one or more voids within a dielectric material that is over the heater element. A void over a heater element may be formed by patterning a sacrificial material feature that is then embedded within the dielectric material. The sacrificial material is removed through an opening in the dielectric material and the opening is then occluded to define a void that may be retained as a permanent feature having a low thermal conductivity. The void over the heater element may, along with one of more voids adjacent to the heater element and/or below an optical waveguide, may enhance thermal isolation of a heater element, enhancing its power efficiency.