FinFET Gate Dielectric Protection Layer Against Contact Bridging
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Solution Overview
Problem
As semiconductor technology nodes shrink, forming contacts for FinFET devices becomes challenging due to the increasingly thin dielectric layer between adjacent device features, leading to potential short-circuit issues as contacts may inadvertently bridge, causing electrical isolation failures.
Innovation Solution
The formation of a dielectric protection layer over the gate trench, which extends along the inner sidewalls and overlays the top surface of the active gate structure, helps maintain electrical separation between adjacent contacts by providing additional isolation even when the interlayer dielectric layer becomes thinner or penetrable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dielectric layer thickness is reduced to increase integration density, then more components can be integrated into a given area, but the likelihood of contact bridging increases causing electrical isolation failures
Solution Approach 1:
A dielectric protection layer is introduced as an intermediary element between adjacent contacts. This protection layer extends along the inner sidewalls of the gate trench and overlays the top surface of the active gate structure, creating an additional isolation barrier that prevents direct electrical contact between adjacent contacts while allowing the interlayer dielectric layer to maintain reduced thickness for high integration density
Solution Approach 2:
The isolation mechanism is extended from a single-layer horizontal barrier to a multi-dimensional structure. The dielectric protection layer wraps around the gate structure in three dimensions, providing isolation not only horizontally between contacts but also vertically along the sidewalls, thereby maintaining electrical isolation even when the planar dielectric layer thickness is reduced
Data Source
AI summary
A semiconductor device includes a semiconductor fin. The semiconductor device includes a gate spacer over the semiconductor fin. A lower portion of the gate spacer surrounds a first region and an upper portion of the gate spacer surrounds a second region. The semiconductor device includes a gate dielectric within the first region. The semiconductor device includes a metal gate within the first region. The semiconductor device includes a dielectric protection layer, in contact with the gate dielectric layer, that includes a first portion within the second region and a second portion lining a top surface of the metal gate.