Semiconductor Seed Layer for Defect-Free Epitaxial Growth
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Solution Overview
Problem
Strain relaxed buffer (SRB) grown on bulk semiconductor substrates faces defect issues and has a thickness limitation for epitaxially grown semiconductor materials due to their critical thickness, restricting the growth of semiconductor layers with mismatched lattice constants.
Innovation Solution
A semiconductor seed layer with a thickness less than its critical thickness is used as a seed layer and strain transfer medium, allowing for the epitaxial growth of defect-free semiconductor layers even beyond their theoretical critical thickness, enabling the growth of strained semiconductor materials without defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If strain relaxed buffer (SRB) is grown on bulk semiconductor substrate, then lattice mismatch is accommodated, but defect issues occur and thickness is limited by critical thickness
Solution Approach 1:
The invention segments the buffer structure into two distinct parts: a traditional SRB layer for accommodating lattice mismatch, and a separate thin seed layer (below critical thickness) that serves as the defect-free template for epitaxial growth. This segmentation allows each layer to perform its specific function without the defects that normally limit total thickness.
Solution Approach 2:
The thin seed layer acts as an intermediary between the SRB and the epitaxially grown semiconductor material. It transfers strain from the SRB while providing a defect-free growth template, enabling thick epitaxial layers to be grown without the defects that would normally occur when growing directly on SRB.
2Length of stationary object
If epitaxial growth thickness exceeds critical thickness, then more material can be grown, but defects occur in the semiconductor layer
Solution Approach 1:
The invention performs preliminary action by creating a thin seed layer below critical thickness that establishes a defect-free growth template before the main epitaxial growth occurs. This preliminary structure prevents defects from forming during subsequent thick material growth, allowing thickness to exceed what would normally be possible.
3Productivity
If thicker semiconductor layers are grown to improve device performance, then more functionality is achieved, but defects increase beyond critical thickness
Solution Approach 1:
The buffer structure is segmented into an SRB layer for strain accommodation and a separate thin seed layer for defect-free growth initiation. This allows thick functional layers to be grown for improved device performance while maintaining low defect density through the seed layer's protective role.
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 enhances semiconductor device performance by allowing thicker epitaxial growth without defects, overcoming the limitations of traditional SRB technologies and improving the stability and performance of semiconductor devices.
Implementation Method 1
the seed section is configured as a strain transfer medium
Implementation Method 2
epitaxially grow another semiconductor material of a different lattice constant than the bulk substrate
Data Source
AI summary
A method for manufacturing a semiconductor device is provided. A semiconductor substrate is received. The semiconductor substrate is patterned to form a plurality of protrusions spaced from one another, wherein the protrusion comprises a base section, and a seed section stacked on the base section. A plurality of first insulative structures are formed, covering sidewalls of the base sections and exposing sidewalls of the seed sections. A plurality of spacers are formed, covering the sidewalls of the seed sections. The first insulative structures are partially removed to partially expose the sidewalls of the base sections. The base sections exposed from the first insulative structures are removed. A plurality of second insulative structures are formed under the seed sections.