Dummy Gate Recess Control With Spacer for Fin Leakage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modern transistors face challenges in reducing source-to-drain leakage current while maintaining on-state current, especially as transistor structures and pitches shrink, impacting power efficiency and performance.
Innovation Solution
The introduction of a spacer material between the channel region and the gate structure, formed by retaining a portion of the dummy gate material, which separates the channel region from unwanted bulges in the fin, thereby controlling conduction and reducing leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If transistor structures and pitches are shrunk to improve device density and performance, then productivity and performance are improved, but source-to-drain leakage current increases and manufacturing precision becomes more difficult to maintain
Solution Approach 1:
A spacer material is introduced as an intermediary element between the gate structure and the fin channel region. This spacer physically separates the gate from unwanted fin bulges and controls the channel formation, thereby reducing source-to-drain leakage current while maintaining proper transistor function at scaled dimensions
Solution Approach 2:
The fin structure is engineered with non-uniform geometry, creating a bulge region with larger cross-sectional area at a specific location. This local quality change allows the fin to better control leakage current through the bulge region while the spacer material ensures the bulge does not compromise channel definition or increase leakage
2Reliability
If the fin cross-sectional area is increased to reduce leakage current, then reliability is improved, but the fin may create unwanted bulges that affect conduction control
Solution Approach 1:
The spacer material serves as a mediator that positions the gate structure at a precise distance from the fin bulge. This ensures the gate properly defines the channel region despite the fin's non-uniform geometry, maintaining manufacturing precision in channel definition while allowing the fin to have the larger cross-sectional area needed for leakage control
3Reliability
If a spacer material is added to separate the gate from fin bulges to reduce leakage, then reliability is improved, but device complexity increases
Solution Approach 1:
The spacer material is formed by depositing a thin film and then selectively removing portions through etching. This extraction approach creates the necessary separation structure in a controlled manner, adding the minimal complexity required to achieve leakage control without unnecessarily complicating the overall device structure
Data Source
AI summary
An integrated circuit (IC) device includes a transistor channel region within (and over a base of) a semiconductor fin, a gate structure over the fin, an isolation or dielectric material adjacent the base of the fin, and an intervening spacer material adjacent the fin, over the dielectric material, and between the channel region (and gate structure) and the isolation or dielectric material. The intervening spacer material may be at substantially equal heights on both sides of the fin. The intervening spacer material may have a height or thickness that is substantial portion of the height of the fin. The spacer and isolation materials may be on both sides of the fin, and between the fin and adjacent fins.