Epitaxial Source/Drain Isolation Layer for Leakage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As minimum feature size reduces in semiconductor devices, issues such as leakage and parasitic devices arise, necessitating improved isolation between source/drain regions to mitigate these side effects.
Innovation Solution
A selective gap fill process is employed to form a high-quality bottom isolation layer using a dielectric material, followed by an epitaxial process to create source/drain regions, enhancing isolation and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If minimum feature size is reduced to increase integration density, then more components can be integrated into a given chip area, but leakage and parasitic devices occur
Solution Approach 1:
The source/drain structure is segmented into multiple discrete regions separated by dielectric material layers. The bottom dielectric layer divides the source/drain into distinct segments, preventing parasitic device formation and leakage between adjacent regions while maintaining high integration density.
Solution Approach 2:
A bottom dielectric layer is introduced as an intermediary material between the source and drain regions. This dielectric layer acts as a mediator that electrically isolates the source/drain regions, eliminating leakage paths and parasitic devices while allowing the miniaturized structure to function properly.
2Ease of manufacture
If conventional isolation methods are used without bottom dielectric layer, then fabrication is simpler, but leakage occurs between source/drain regions across gate structure
Solution Approach 1:
The bottom dielectric layer is formed preliminarily before the source/drain regions are created. This preliminary isolation layer is deposited and patterned in advance, establishing electrical isolation boundaries before the conductive source/drain regions are formed, thereby preventing leakage from the outset.
Solution Approach 2:
The dielectric material is selectively placed only where isolation is needed - specifically at the bottom of source/drain regions and in mesa regions beneath the gate structure. This localized application of dielectric material provides targeted leakage prevention without complicating the overall fabrication process.
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
The solution provides effective isolation between source/drain regions, reducing leakage and parasitic device formation, thereby improving device performance and reliability.
Implementation Method 1
depositing a first material layer
Implementation Method 2
treating the first material layer to convert the first material layer into a dielectric-containing material layer
Implementation Method 3
growing an epitaxial source/drain region over the bottom isolation layer
Data Source
AI summary
Embodiments with present disclosure provides a gate-all-around FET device including a bottom isolation layer. The bottom isolation layer prevents leaks around the source/drain regions and improve device performance.