Semiconductor Substrate Stressing via Thermal Expansion and Pressure
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Solution Overview
Problem
There is a continuing need for apparatus capable of effectively stressing semiconductor substrates, which existing technologies have not adequately addressed.
Innovation Solution
The apparatus includes a chamber with a heater and a substrate holder that can bend or stress the semiconductor substrate using a combination of thermal expansion and pressure modulation, with features such as elongate pins, rings, and a pressure modulator to exert stress on the substrate, allowing it to move between a planar and bent position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a substrate holder with multiple support points is used to stress the substrate, then stress distribution is improved, but device complexity increases
Solution Approach 1:
The substrate holder is segmented into multiple discrete support pins arranged in specific patterns (e.g., triangular, circular) rather than a continuous support surface. This segmentation allows selective contact at key stress points while simplifying the overall holder structure to a framework of isolated pins rather than a complex continuous support mechanism.
Solution Approach 2:
Different regions of the substrate holder provide different support characteristics - some pins contact the substrate to provide stress concentration points, while other pins provide support without stress. The holder structure itself has varying thickness and material properties in different regions to optimize stress distribution while maintaining structural simplicity.
2Device complexity
If thermal expansion is used to stress the substrate, then stress application is simplified, but temperature control precision must be maintained
Solution Approach 1:
The system utilizes changes in thermal expansion parameters of different materials (substrate vs. holder) to generate stress. By selecting materials with significantly different thermal expansion coefficients and controlling the temperature change magnitude, the system achieves effective stress application through straightforward thermal cycling rather than complex mechanical actuation mechanisms.
3Stress or pressure
If pressure differential is applied across the substrate, then stress magnitude is improved, but energy consumption increases
Solution Approach 1:
A pressure modulator uses pneumatic or hydraulic principles to create pressure differentials across the substrate by controlling fluid flow through channels in the substrate holder. This approach generates substantial stress forces through relatively small energy inputs by leveraging fluid pressure amplification rather than direct mechanical force application.
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 apparatus efficiently applies stress to semiconductor substrates, enabling processes like epitaxial layer deposition and ensuring uniform stress distribution, thereby improving substrate processing outcomes.
Implementation Method 1
The apparatus includes a chamber with a heater and a substrate holder that can bend or stress the semiconductor substrate using a combination of thermal expansion and pressure modulation
Implementation Method 2
a pressure modulator for causing a pressure differential across the substrate sufficient to exert stress on the substrate
Data Source
AI summary
Apparatus for use in preparing heterostructures having a reduced concentration of defects including apparatus for stressing semiconductor substrates to allow them to conform to a crystal having a different crystal lattice constant.