Merged FinFET Channel Strain via Epitaxial Growth
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Solution Overview
Problem
Conventional FinFET devices face challenges in maintaining strain as technology nodes scale down, leading to stress relaxation and defects in raised source and drain features, which negatively impact device performance.
Innovation Solution
The method involves merging fins to form a fin template, allowing for self-aligned source/drain template growth, which minimizes stress relaxation and maximizes strain in the channel, achieved by epitaxially growing semiconductor material over the fin template.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional FinFET devices are used with separate fins, then device density can be maintained, but strain is lost and stress relaxation occurs in raised source and drain features
Solution Approach 1:
The patent merges adjacent fins into a consolidated fin structure with raised source and drain features, replacing the conventional separate fin architecture. This merging maintains strain in the channel region while preventing stress relaxation in the raised source/drain features, thereby resolving the contradiction between strain maintenance and device density.
Solution Approach 2:
The invention employs composite material structures by integrating different semiconductor materials (e.g., SiGe, SiC) into the fin and raised source/drain regions. This composite approach enables simultaneous achievement of high strain, stress relaxation prevention, and compact device layout, addressing both reliability and productivity concerns.
2Reliability
If fins are merged to form a fin template, then strain is maximized in the channel, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by forming the merged fin template structure before creating the raised source and drain features. This sequential approach simplifies manufacturing by establishing the strain-maximizing fin geometry first, then adding the raised source/drain features in subsequent processing steps, rather than attempting to form both simultaneously.
Solution Approach 2:
The manufacturing process is segmented into distinct stages: first forming the merged fin template, then separately forming the raised source and drain features. This segmentation of the manufacturing process reduces overall complexity by breaking down the complex structure formation into manageable, sequential steps.
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 FinFET device performance by providing maximum strain to the channels with minimal defects, improving carrier mobility and reducing stress relaxation issues.
Implementation Method 1
epitaxially growing a semiconductor material over the fin template
Data Source
AI summary
A FinFET device and method for fabricating a FinFET device is disclosed. An exemplary method includes providing a semiconductor substrate; forming a first fin structure and a second fin structure over the semiconductor substrate; forming a gate structure over a portion of the first and second fin structures, such that the gate structure traverses the first and second fin structures; epitaxially growing a first semiconductor material on exposed portions of the first and second fin structures, such that the exposed portions of the first and second fin structures are merged together; and epitaxially growing a second semiconductor material over the first semiconductor material.