Optical Ring Resonator Backside Recess Thermal Isolation
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Solution Overview
Problem
Existing optical ring resonator structures face challenges in heat localization due to heat flow into substrates and metal traces, making it difficult to stabilize resonance frequencies effectively, and current techniques for heat localization are complex and prone to errors.
Innovation Solution
A backside recess on the substrate, centered on the optical ring resonator and extending into metal traces, thermally isolates the resonator from the substrate, reducing heat extraction through metal traces and simplifying the etching process, thereby improving yield and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If side etching is used to localize heat, then heat localization is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
Instead of etching from the device side to create isolation structures, the patent inverts the approach by etching recesses from the backside of the substrate. This inversion simplifies the etching process while achieving the same heat localization effect, as the recesses naturally form thermal isolation structures without requiring complex masking and etching control.
Solution Approach 2:
The patent transitions from two-dimensional side etching to three-dimensional backside recesses. By creating recesses that extend vertically into the substrate from the backside, the solution adds a vertical dimension to heat isolation, effectively blocking heat flow paths without requiring complex lateral etching patterns.
2Temperature
If side etching is used to isolate heat, then thermal isolation is improved, but manufacturing precision requirements increase
Solution Approach 1:
By inverting the etching direction to access the substrate from the backside, the patent eliminates the need for precise masking and lateral etching control. The recesses are etched vertically downward, a process that is inherently more controllable and less sensitive to positioning errors compared to side etching.
3Device complexity
If no recess is used, then device simplicity is maintained, but heat extraction through substrate increases
Solution Approach 1:
The patent extracts material from the substrate to form recesses beneath the optical ring resonator and heater. By removing substrate material in these locations, heat extraction paths through the substrate are blocked, forcing heat to remain localized at the device while maintaining overall structural simplicity.
4Loss of energy
If recess extends into metal traces, then heat extraction through traces is reduced, but manufacturing complexity increases
Solution Approach 1:
By etching from the backside, the patent can extend recesses laterally under metal traces without affecting the traces themselves. This inverted approach allows the recesses to intercept heat flow paths beneath the traces while keeping the traces intact and simple in geometry.
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 backside recess effectively reduces heat flow into the substrate, enhances thermal isolation, and simplifies the etching process, leading to improved yield and efficiency in stabilizing resonance frequencies and reducing power consumption in optical telecommunications devices.
Implementation Method 1
The optical ring structure is thermally isolated from the substrate by virtue of the recess
Implementation Method 2
Resonance frequencies of optical ring resonators are stabilized using integrated heaters, which heat an optical ring resonator to a given temperature
Data Source
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AI summary
An optical ring resonator structure with a backside recess is provided at a device. The device includes: a substrate having a device-side and a backside opposite the device-side; an optical ring resonator located on the device-side of the substrate; a heater having a shape complementary to the optical ring resonator, the heater positioned to heat the optical ring resonator; and one or more metal traces that connect at least to the heater, the metal traces configured to provide power to the heater and extending outward from the heater. The device further includes a recess on the backside of the substrate, the recess centered on the optical ring resonator, and having a diameter larger than both respective outer diameters of the optical ring resonator and the heater, the recess further extending laterally into a region of the one or more metal traces.