Silicon Ring Modulator Heater Layout Without Extra Metal Routing

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Solution Overview

Problem

Micro ring modulators (MRMs) in silicon photonics are sensitive to process variation and require integrated micro heaters for wavelength control, complicating electrical routing due to P/N junction issues, especially when using doped silicon heaters.

Innovation Solution

A silicon photonic semiconductor device with a doped silicon heater design that integrates thermal resistance regions on the inner and outer ring portions of the silicon ring, eliminating the need for additional metal heating elements and their routing by utilizing reverse bias voltages to maintain a depletion region and control temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If doped silicon heater is used for wavelength control in MRM, then thermal efficiency is improved and electron migration reliability is enhanced, but electrical routing complexity increases due to P/N junction requirements

Engineering Contradiction:

Improveelectron migration reliabilityVSAvoidelectrical routing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The heater electrodes are merged with the P/N junction structure of the MRM. The first heater electrode is formed as the P-type doped region and the second heater electrode is formed as the N-type doped region, combining the heating function with the existing junction structure. This eliminates the need for separate metal heater routing while maintaining doped silicon thermal efficiency.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The P-type and N-type doped regions serve dual functions: they form the P/N junction for the MRM operation and simultaneously act as heater electrodes for wavelength control. This multi-functionality reduces device complexity by eliminating dedicated heater routing while maintaining both modulation and heating capabilities.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Stability of the object's composition

If integrated micro heater is added for wavelength control, then wavelength stability is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvewavelength stabilityVSAvoiddevice structure complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The wavelength control heater is merged with the MRM structure by using the P-type and N-type doped regions as heater electrodes. This integration eliminates the need for separate micro heater components while maintaining wavelength stability through thermal control of the resonant wavelength.

Inventive Principle:

Principle #5Merging (Combining)

3Temperature

If additional metal heating elements are integrated, then thermal control capability is improved, but manufacturing process complexity increases

Engineering Contradiction:

Improvethermal control capabilityVSAvoidmanufacturing process simplicity

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The heating function is merged into the existing doping process. The P-type and N-type doped regions are formed using standard semiconductor doping techniques during MRM fabrication, eliminating the need for separate metal heater deposition and patterning processes. This maintains thermal control capability while simplifying manufacturing.

Inventive Principle:

Principle #5Merging (Combining)

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 solution provides a compact footprint and efficient thermal management without additional routing, enhancing thermal efficiency and simplifying the manufacturing process while maintaining operational bias voltages.

Implementation Method 1

the heater includes a first silicon thermal resistance region and a second silicon thermal resistance region... the first heater electrode and the second heater electrode are configured to apply a reverse bias voltage to the P/N junction

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the first heater electrode and the second heater electrode are configured to apply a reverse bias voltage to the P/N junction formed between the outer ring portion and the inner ring portion

Methodology Applied

Scientific EffectDepletion region:

Data Source

PatentUS20260063840A1Silicon photonic semiconductor device and manufacturing method thereof

Publication Date: 2026.03.05 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A silicon photonic semiconductor device includes a modulator and a heater. The modulator includes a bus waveguide and a silicon ring. The silicon ring is optically coupled to the bus waveguide, and the heater is configured to heat the silicon ring. The heater includes a first silicon thermal resistance region and a second silicon thermal resistance region. The first silicon thermal resistance region is disposed on an outer ring portion of the silicon ring, and the outer ring portion has a first conductivity type doping. The second silicon thermal resistance region is disposed on an inner ring portion of the silicon ring and the inner ring portion has a second conductivity type dopant. The first conductivity type dopant and the second conductivity type dopant have different electrical properties.