Selective Etching of Epitaxial Defects in Semiconductor Fin Structures
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Solution Overview
Problem
Semiconductor devices with epitaxially-deposited materials often suffer from defects due to mismatched molecular lattices at the interface between the substrate and the deposited materials, leading to reduced strength, functionality, and increased power consumption, as well as early component failures and latent defects.
Innovation Solution
A method involving selective etching and polishing of defect regions in epitaxially grown fin structures, followed by annealing and backfilling with lattice-compatible materials to remove or reduce defects, enabling integration of challenging semiconductor materials like Silicon-Germanium and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If epitaxially-deposited materials are used to increase compactness and functionality, then device functionality is improved, but defect regions are generated due to lattice mismatch
Solution Approach 1:
The patent extracts and removes the harmful defect regions from the semiconductor structure through selective etching processes. The defect regions at the interface between epitaxially-deposited materials and substrate are selectively removed while preserving the functional epitaxial structures, thereby eliminating reliability issues while maintaining device functionality.
Solution Approach 2:
The patent applies different material compositions and processing conditions to different regions of the semiconductor structure. By creating graded compositions and selective etching conditions, the patent achieves local optimization where defect regions are removed while functional regions are preserved, resolving the contradiction between functionality and reliability.
2Device complexity
If defect regions are left within semiconductor devices, then manufacturing complexity is reduced, but early component failures and latent defects occur
Solution Approach 1:
The patent performs preliminary removal of defect regions through selective etching before final device assembly and testing. By addressing the defect regions early in the manufacturing process, the patent prevents future failures without adding significant complexity to the overall manufacturing workflow.
3Reliability
If defect regions are removed through selective etching and polishing, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent introduces intermediary layers and selective etching mediators that enable the removal of defect regions without requiring complex multi-step processing. The intermediary approaches facilitate selective removal while maintaining simplicity in the overall manufacturing process, thus improving reliability without proportionally increasing manufacturing complexity.
4Volume of moving object
If epitaxially-deposited materials with different composition are used, then device compactness is improved, but leakage current increases
Solution Approach 1:
The patent extracts and removes the defect regions that are the source of leakage current while preserving the compact epitaxial structures. By selectively removing only the defective interface regions and not the functional epitaxial materials, the patent eliminates leakage current while maintaining device compactness.
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 leakage current and enhances the integration of disparate semiconductor materials, improving the reliability and efficiency of semiconductor devices by eliminating defect regions and allowing for angled contours and integrated wiring within fin structures.
Implementation Method 1
annealing the fin structure
Implementation Method 2
selective etching and polishing of defect regions
Implementation Method 3
selective etching and polishing of defect regions
Data Source
AI summary
Methods and apparatus to remove epitaxial defects in semiconductors are disclosed. A disclosed example multilayered die structure includes a fin having a first material, where the fin is epitaxially grown from a first substrate layer having a second material, and where a defect portion of the fin is etched or polished. The disclosed example multilayered die structure also includes a second substrate layer having an opening through which the fin extends.