Gate Spacer Structure for Replacement Gate Formation Precision

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Solution Overview

Problem

The shape of the gate spacer in semiconductor devices significantly affects the process of forming replacement gate electrodes, and existing technologies struggle to optimize this shape for improved electrical properties.

Innovation Solution

The semiconductor device includes a gate spacer on the side surface of the gate electrode, extending into an undercut region between the gate electrode and the active region, which helps in reducing defects during the gate electrode formation process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the gate spacer shape is optimized for replacement gate electrode formation, then manufacturing precision improves, but device complexity increases

Engineering Contradiction:

Improvegate spacer shape precisionVSAvoidgate spacer structure complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The gate spacer is divided into multiple distinct portions: a first portion formed on the side surface of the gate electrode, and a second portion extending into the undercut region. This segmentation allows each portion to be optimized independently for its specific function, improving overall manufacturing precision while managing complexity through functional separation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the gate spacer are designed with different geometries and dimensions tailored to their specific locations and functions. The first portion has dimensions optimized for side surface coverage, while the second portion has dimensions optimized for undercut region extension, achieving local optimization that improves manufacturing precision.

Inventive Principle:

Principle #3Local quality

2Reliability

If the gate spacer extends into the undercut region, then reliability improves, but ease of manufacture deteriorates

Engineering Contradiction:

Improvedevice electrical propertiesVSAvoidgate spacer fabrication

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The gate spacer structure is designed and formed before the replacement gate electrode formation process begins. By preliminarily establishing the gate spacer with its extended portion in the undercut region, the subsequent replacement gate electrode formation can proceed without additional complex steps, improving reliability while maintaining ease of manufacture.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The gate spacer acts as an intermediary structure that facilitates the replacement gate electrode formation process. Its extended portion in the undercut region serves as a guide and support structure, enabling precise formation of the replacement gate electrode while simplifying the overall manufacturing process.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12310079B2Semiconductor devices including gate spacer

Publication Date: 2025.05.20 SAMSUNG ELECTRONICS CO LTD

AI summary

A semiconductor device includes a first active region defined on a substrate, a first gate electrode across the first active region, a first drain region in the first active region at a position adjacent to the first gate electrode, an undercut region between the first active region and the first gate electrode, and a first gate spacer on a side surface of the first gate electrode and extending into the undercut region.