Epitaxial Substrate Balance Structure for Thermal Stress Warpage
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Solution Overview
Problem
In the epitaxial substrate manufacturing process, stress accumulation due to differences in thermal expansion coefficients and lattice sizes between substrate and epitaxial layer materials leads to substrate warpage, affecting the quality and optical characteristics of subsequent products.
Innovation Solution
An epitaxial semiconductor structure with a balance structure composed of non-continuous particulate materials on the substrate's second surface, which balances thermal stress by reversing the stress direction and allowing flexible epitaxy conditions, thereby adjusting and controlling warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a substrate and epitaxial layer with heterogeneous materials are used, then different material properties can be achieved, but stress accumulates due to differences in coefficient of thermal expansion and lattice size
Solution Approach 1:
A buffer layer is introduced between the substrate and the epitaxial layer to act as an intermediary that reduces stress accumulation. The buffer layer has intermediate material properties that bridge the mismatch between the substrate and epitaxial layer, thereby reducing thermal stress while still allowing heterogeneous material combinations.
Solution Approach 2:
The thickness of the buffer layer is optimized to control stress distribution. By adjusting the buffer layer thickness parameter, the stress accumulation is reduced to an acceptable level while maintaining the benefits of heterogeneous material properties. The buffer layer thickness is set to a specific range to achieve optimal stress reduction.
2Reliability
If stress accumulation occurs in the epitaxy process, then substrate warpage occurs, but this affects thermal field and flow field evenness
Solution Approach 1:
The buffer layer serves as a mediator that decouples the stress transmission between substrate and epitaxial layer, preventing warpage while maintaining substrate stability. This allows the thermal field and flow field to remain uniform during the epitaxy process.
3Manufacturing precision
If substrate warpage occurs, then quality of epitaxial substrate is reduced, but this affects optical characteristics of subsequent products
Solution Approach 1:
The buffer layer is prepared in advance before the epitaxial growth process to prevent warpage from occurring during epitaxy. This preliminary stress management ensures that the epitaxial substrate maintains high quality and uniformity, which directly improves the optical characteristics of subsequent products.
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 effectively reduces warpage and improves the quality of the epitaxial semiconductor structure, resulting in better optical characteristics and more even thermal energy distribution during the epitaxy process.
Implementation Method 1
stress is likely to be accumulated due to differences in coefficient of thermal expansion and lattice size between the materials
Implementation Method 2
affects the thermal field and flow field evenness around the substrate
Data Source
AI summary
An epitaxial semiconductor structure including a substrate, a semiconductor layer, and a balance structure is provided. The substrate has a first surface and a second surface opposite to each other. The semiconductor layer is formed on the first surface. The balance structure is formed on the second surface, the balance structure is configured to balance the thermal stress on the substrate, and the balance structure is composed of a plurality of non-continuous particulate materials. An epitaxial substrate is also provided.