Silicon Photonics Micro Heater Oxide Capping for Thermal Stress Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Micro heaters in silicon photonics devices face reliability issues due to high temperatures causing thermal expansion mismatches and film cracking, which degrade device performance and longevity, and reducing operating temperature requires complex design or fabrication control.
Innovation Solution
A single oxide capping structure is applied over the micro heater to alleviate thermal stress by reducing temperature and stress, using oxide material to cap the micro heater and alter heat flow, thereby minimizing thermal mismatch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If micro heaters operate at high temperatures to achieve optical tuning functions, then wavelength tuning and phase control capabilities are improved, but thermal expansion mismatches and film cracking occur leading to reduced device reliability
Solution Approach 1:
An oxide capping layer is introduced as an intermediary between the metal heater and the surrounding structures. This capping layer has thermal expansion properties that bridge the gap between metal and dielectric materials, reducing thermal stress and preventing film cracking during high-temperature operation while maintaining the heater's optical tuning functionality
Solution Approach 2:
The thermal and mechanical properties of the heater structure are modified by adding the oxide capping layer, which changes the overall thermal expansion coefficient and stress distribution of the heater assembly, allowing it to withstand high-temperature operation without structural failure
2Reliability
If operating temperature is reduced to prevent thermal expansion mismatches and film cracking, then device reliability is improved, but optical tuning performance and wavelength control capability deteriorate
Solution Approach 1:
The oxide capping layer serves as a stress-buffer intermediary that decouples the relationship between operating temperature and structural integrity, allowing the device to maintain high temperature for optimal optical performance while the capping layer prevents thermal expansion mismatches and film cracking
3Stress or pressure
If complex design or fabrication control is implemented to reduce operating temperature, then thermal stress is reduced, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The complex design and fabrication control measures are extracted and replaced by a simple structural modification - adding an oxide capping layer during the standard fabrication process. This eliminates the need for complex temperature management schemes while effectively reducing thermal stress
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 oxide capping structure reduces temperature by 15% and thermal stress by 46%, preventing structural defects and enhancing device reliability and longevity.
Implementation Method 1
A single oxide capping structure is applied over the micro heater to alleviate thermal stress by reducing temperature and stress, using oxide material to cap the micro heater and alter heat flow
Implementation Method 2
Micro heaters serve multiple functions in optical semiconductor structures. One of their primary roles is facilitating the thermal tuning of the optical properties of semiconductor devices. By locally heating specific regions of the device
Data Source
AI summary
A semiconductor structure is provided. The semiconductor structure includes a substrate, a waveguide, a heating structure, a back-end-of-line (BEOL) structure, and a capping oxide structure. The waveguide is over the substrate. The heating structure is over the waveguide. The BEOL structure is over the waveguide. The capping oxide structure penetrates the BEOL structure and covers the heating structure. The capping oxide structure includes a continuous sidewall extended from a top side of the BEOL structure to a bottom side of the BEOL structure. A method for manufacturing a semiconductor structure is also provided.