Ge-Gradient Capping Layers for MOSFET Threshold Voltage Control

Solution Overview

Problem

The reduction in size of MOSFETs in semiconductor devices has led to deteriorating operating characteristics, necessitating the development of methods to enhance performance while overcoming integration limitations.

Innovation Solution

A semiconductor device design that includes a substrate with a peripheral region and a logic cell region, featuring a first active pattern with alternately stacked first and second semiconductor patterns, a first gate electrode, source/drain patterns, and capping layers with varying germanium concentrations to improve electrical characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If MOSFET size is reduced to increase integration density, then device miniaturization is achieved, but operating characteristics deteriorate

Engineering Contradiction:

ImproveMOSFET device areaVSAvoidoperating characteristics

Core Design Contradiction:

Area of moving objectVSReliability

Solution Approach 1:

The patent applies local quality by forming capping layers with different germanium concentrations at different locations on the active pattern. The first capping layer has a higher germanium concentration than the second capping layer, creating localized material property variations that improve carrier mobility and threshold voltage control in the scaled-down device while maintaining overall device miniaturization.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the compositional parameter of the capping layers by varying germanium concentration. The first capping layer contains a higher germanium concentration than the second capping layer, which modifies the electrical characteristics of the underlying semiconductor channel, thereby improving operating characteristics despite reduced device size.

Inventive Principle:

Principle #35Parameter changes

2Area of moving object

If MOSFET size is reduced to increase integration density, then device miniaturization is achieved, but threshold voltage control deteriorates

Engineering Contradiction:

ImproveMOSFET device areaVSAvoidthreshold voltage control

Core Design Contradiction:

Area of moving objectVSManufacturing precision

Solution Approach 1:

The patent applies local quality by forming capping layers with different germanium concentrations at different locations on the active pattern. The first capping layer has a higher germanium concentration than the second capping layer, creating localized material property variations that improve carrier mobility and threshold voltage control in the scaled-down device while maintaining overall device miniaturization.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the compositional parameter of the capping layers by varying germanium concentration. The first capping layer contains a higher germanium concentration than the second capping layer, which modifies the electrical characteristics of the underlying semiconductor channel, thereby improving operating characteristics despite reduced device size.

Inventive Principle:

Principle #35Parameter changes

3Area of moving object

If MOSFET size is reduced to increase integration density, then device miniaturization is achieved, but power consumption increases

Engineering Contradiction:

ImproveMOSFET device areaVSAvoidoperational power

Core Design Contradiction:

Area of moving objectVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by forming capping layers with different germanium concentrations at different locations on the active pattern. The first capping layer has a higher germanium concentration than the second capping layer, creating localized material property variations that improve carrier mobility and threshold voltage control in the scaled-down device while maintaining overall device miniaturization.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the compositional parameter of the capping layers by varying germanium concentration. The first capping layer contains a higher germanium concentration than the second capping layer, which modifies the electrical characteristics of the underlying semiconductor channel, thereby improving operating characteristics despite reduced device size.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12278271B2Semiconductor device having capping layers with different germanium concentrations over an active pattern

Publication Date: 2025.04.15 SAMSUNG ELECTRONICS CO LTD

AI summary

A semiconductor device includes a substrate including a peripheral region, a first active pattern on the peripheral region, the first active pattern having an upper portion including first semiconductor patterns and second semiconductor patterns, which are alternately stacked, a first gate electrode intersecting the first active pattern, a pair of first source/drain patterns provided at both sides of the first gate electrode, respectively, a first capping layer on the first active pattern, a second capping layer on the first capping layer, and a first gate insulating layer between the second capping layer and the first gate electrode. The first capping layer is between a sidewall of the first active pattern and the second capping layer. A concentration of germanium (Ge) of the first capping layer is greater than a concentration of germanium of the second capping layer.