Epitaxial Oxide Fin Segments Prevent Strain Relaxation
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Solution Overview
Problem
Fin structures composed of strained semiconductor materials tend to relax after cutting, leading to loss of performance advantages and inconsistent strain profiles, which degrade device performance.
Innovation Solution
The method involves forming fin structures with epitaxial oxide in the fin cut space to obstruct strain relaxation, using a hard mask on a semiconductor substrate, etching openings, and depositing semiconductor material with a different lattice dimension to induce strain, ensuring the epitaxial oxide is present between source and drain edges to maintain strain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fin structures are cut after forming strained semiconductor material, then device fabrication is completed, but strain relaxation occurs leading to performance degradation
Solution Approach 1:
The epitaxial oxide is formed in the fin cut space before the fin structures are cut, creating a protective barrier in advance that prevents strain relaxation when the cut occurs. This preliminary placement of the oxide material ensures that when subsequent processing steps separate the fin structures, the strain is already protected from relaxation pathways.
2Reliability
If epitaxial oxide is added to fin cut space, then strain relaxation is prevented, but device structure complexity increases
Solution Approach 1:
The epitaxial oxide acts as an intermediary material placed in the fin cut space between the strained semiconductor fin structures. This intermediary layer physically blocks the relaxation of strain by occupying the space where relaxation would normally occur, transferring the compressive strain from the fin to the oxide material itself.
3Speed
If uniform strain is maintained across fin structures, then carrier speed is enhanced, but manufacturing process complexity increases
Solution Approach 1:
The solution applies local quality by placing the epitaxial oxide specifically in the fin cut space rather than uniformly throughout the entire device structure. This localized application of the oxide material provides strain protection precisely where needed at the fin edges while maintaining the strained semiconductor material integrity in the channel regions, thereby enhancing carrier speed without requiring global structural modifications.
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 maintains uniform strain across fin structures, preventing relaxation and enhancing carrier speeds, thereby improving device performance by ensuring consistent strain profiles.
Implementation Method 1
An epitaxial deposited semiconductor material having a second lattice dimension that is different than the first lattice dimension may be formed in the second openings, wherein a difference between the first lattice dimension and the second lattice dimension induces a strain in the epitaxial deposited semiconductor material
Implementation Method 2
An epitaxial oxide having a second lattice dimension than the first lattice dimension of the semiconductor substrate may then be formed in openings
Data Source
AI summary
A method of forming a semiconductor device that includes providing regions of epitaxial oxide material on a substrate of a first lattice dimension, wherein regions of the epitaxial oxide material separate regions of epitaxial semiconductor material having a second lattice dimension are different than the first lattice dimension to provide regions of strained semiconductor. The regions of the strained semiconductor material are patterned to provide regions of strained fin structures. The epitaxial oxide that is present in the gate cut space obstructs relaxation of the strained fin structures. A gate structure is formed on a channel region of the strained fin structures separating source and drain regions of the fin structures.