FinFET SDB Structure Fabrication for Threshold Voltage Control
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Solution Overview
Problem
Current FinFET fabrication methods face challenges in integrating single diffusion break (SDB) structures and metal gate fabrication, which affect the control of the channel region and threshold voltage in three-dimensional transistor technology.
Innovation Solution
A method involving the formation of fin-shaped structures on a substrate, followed by the creation of trenches and dielectric layers to form SDB structures of different heights, allowing for improved control over the channel region and threshold voltage through the use of patterned masks and dielectric materials, and subsequent metal gate integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If shallow trench isolation (STI) is formed around the fin-shaped structure and insulating material is deposited into the trench to form single diffusion break (SDB) structure, then the channel region control is improved, but the integration with metal gate fabrication remains problematic and complex
Solution Approach 1:
The fin-shaped structure is divided into multiple segments by forming trenches between adjacent fins. The patterned mask selectively removes portions of the gate structure and fin structure to create isolated trenches, effectively segmenting the continuous fin structure into discrete regions with improved channel control while simplifying the overall integration process
Solution Approach 2:
The invention transitions from planar SDB structures to three-dimensional SDB structures by forming trenches that extend vertically through the fin structure. The dielectric material is deposited to create SDB structures with varying heights relative to the gate structure, adding a vertical dimension that improves channel region control while enabling better integration with metal gate fabrication
2Productivity
If the three-dimensional structure of FinFET is used to increase overlapping area between gate and fin-shaped structure, then the channel region control is improved and current is increased, but the integration of SDB structure and metal gate fabrication remains problematic
Solution Approach 1:
The trenches are formed and SDB structures are prepared in advance before final gate structure completion. The patterned mask is used to pre-defines the trench locations and remove portions of the fin structure, allowing subsequent dielectric deposition to create SDB structures that are already positioned and sized correctly for optimal integration with the metal gate fabrication process
Data Source
AI summary
A method for fabricating semiconductor device includes the steps of: providing a substrate having a first region and a second region; forming a first fin-shaped structure on the first region; forming a first gate structure and a second gate structure on the first fin-shaped structure; using a patterned mask to remove the first gate structure and part of the first fin-shaped structure to form a first trench; and forming a first dielectric layer in the first trench to form a first single diffusion break (SDB) structure and around the second gate structure.