FinFET Liner Structure for Preventing Fin Bending

Solution Overview

Problem

Existing FinFET devices face challenges in maintaining fin structure integrity and preventing bending due to uneven stress, which affects device performance.

Innovation Solution

The formation of inner liner layers higher than outer liner layers on fin structures, achieved through controlled etching processes, ensures even stress distribution and maintains fin profile, preventing bending and enhancing device performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional liner layers are formed uniformly on fin structures, then the fabrication process is simple, but uneven stress causes fin bending and compromises device performance

Engineering Contradiction:

Improvefin structure integrityVSAvoidliner layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by forming inner liner layers with different properties than outer liner layers. Specifically, the inner liner layer is formed to a first thickness while the outer liner layer is formed to a second thickness greater than the first thickness, creating non-uniform stress distribution that compensates for intrinsic stress in the fin structure and prevents bending.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements asymmetry by creating an asymmetric liner layer structure where the outer liner layer has greater thickness than the inner liner layer. This asymmetric configuration generates differential stress that counteracts the intrinsic stress causing fin bending, thereby maintaining fin structure integrity without requiring complex fabrication processes.

Inventive Principle:

Principle #4Asymmetry

2Ease of manufacture

If uniform liner layers are used on fin structures, then fabrication is easier, but fin bending occurs due to intrinsic stress

Engineering Contradiction:

Improveliner layer formationVSAvoidfin profile

Core Design Contradiction:

Ease of manufactureVSShape

Solution Approach 1:

The patent applies local quality by forming inner liner layers with different properties than outer liner layers. Specifically, the inner liner layer is formed to a first thickness while the outer liner layer is formed to a second thickness greater than the first thickness, creating non-uniform stress distribution that compensates for intrinsic stress in the fin structure and prevents bending.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements asymmetry by creating an asymmetric liner layer structure where the outer liner layer has greater thickness than the inner liner layer. This asymmetric configuration generates differential stress that counteracts the intrinsic stress causing fin bending, thereby maintaining fin structure integrity without requiring complex fabrication processes.

Inventive Principle:

Principle #4Asymmetry

Data Source

PatentUS20240178224A1Method for forming fin field effect transistor (finfet) device structure

Publication Date: 2024.05.30 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method for forming a FinFET device structure is provided. The FinFET device structure includes a first fin structure extending above a substrate, and a first liner layer formed on a first sidewall surface of the first fin structure. The FinFET device structure includes a gate dielectric layer formed over the first fin structure and the first liner layer, wherein a sidewall surface of the gate dielectric layer is aligned with a sidewall surface of the first liner layer.