Semiconductor Substrate Etching to Suppress Epitaxial Stacking Faults
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Solution Overview
Problem
The formation of stacking faults in epitaxial layers grown on semiconductor substrates is a significant issue, as these defects can lead to voltage abnormalities in power devices and reduce the reliability of semiconductor devices.
Innovation Solution
A method that involves removing the subsurface damaged layer from the semiconductor substrate through etching or other machining processes, followed by crystal growth on the cleaned surface to suppress the formation of in-growth stacking faults.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multi-stage mechanical grinding and polishing are performed to remove the subsurface damaged layer, then the substrate surface is planarized and the damaged layer is reduced, but stacking faults are formed during the process
Solution Approach 1:
The patent extracts and removes the subsurface damaged layer through chemical etching before epitaxial growth. By selectively removing the damaged layer introduced during substrate fabrication, the source of stacking faults is eliminated, allowing high-quality epitaxial layers to be grown on clean, undamaged substrate surfaces
Solution Approach 2:
The patent introduces chemical etching as an intermediary process between substrate preparation and epitaxial growth. This intermediate step uses chemical etchants to selectively remove the subsurface damaged layer without causing mechanical damage, thereby preventing stacking fault formation during subsequent growth processes
2Productivity
If the subsurface damaged layer is not removed, then the substrate can be used directly for epitaxial growth, but stacking faults form in the epitaxial layer reducing device reliability
Solution Approach 1:
The patent applies preliminary chemical etching to remove the subsurface damaged layer before epitaxial growth begins. This preliminary action eliminates the source of stacking faults in advance, ensuring that the subsequent high-speed epitaxial growth produces defect-free layers without requiring post-growth defect correction
Solution Approach 2:
The patent changes the processing parameters by introducing chemical etching conditions (etchant composition, temperature, time) that selectively remove the subsurface damaged layer. By optimizing these parameters, the damaged layer is removed while maintaining substrate integrity and enabling high-speed epitaxial growth without stacking faults
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
This approach effectively reduces the density of in-growth stacking faults, thereby improving the reliability and performance of semiconductor devices by eliminating defects that can cause voltage abnormalities.
Implementation Method 1
the subsurface damaged layer removal step is a step of etching the semiconductor substrate
Implementation Method 2
a crystal growth step of performing crystal growth on a surface from which the subsurface damaged layer is removed
Data Source
AI summary
The problem to be solved is to provide a new technology capable of suppressing the formation of stacking faults. The problem to be solved is to provide a new technology capable of suppressing stacking defects formed during epitaxial growth on a semiconductor substrate. The present invention is a method for suppressing formation of stacking faults, comprising a subsurface damaged layer removal step S10 of removing a subsurface damaged layer 11 of a semiconductor substrate 10, a crystal growth step S20 of performing crystal growth on a surface from which the subsurface damaged layer 11 is removed.