Multi-Layer Gate Spacer Structure for Hot Carrier Leakage Reduction
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Solution Overview
Problem
Conventional electronic devices with metal oxide semiconductors (MOS) in high-voltage semiconductor elements are insufficient in addressing hot carrier injection (HCI) issues, which affect performance and fail to meet current or future requirements due to increased miniaturization and performance demands.
Innovation Solution
A semiconductor structure is designed with a second and third spacer layer extending from the gate electrode to the source/drain, increasing the width of the gate spacer to reduce leakage current caused by HCI.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gate spacer width is increased to reduce leakage current from hot carrier injection, then device reliability improves, but device complexity increases due to multiple spacer layers
Solution Approach 1:
The gate spacer is divided into multiple distinct layers (first spacer layer, second spacer layer, third spacer layer) with different materials and functions. Each layer serves a specific purpose in preventing hot carrier injection while managing device complexity through functional segmentation rather than a single complex structure
Solution Approach 2:
The gate spacer employs composite material structure where the first spacer layer, second spacer layer, and third spacer layer are made of different materials with complementary properties. This composite approach enables each layer to contribute differently to hot carrier injection prevention, achieving superior reliability through material diversity rather than increasing overall structural complexity
2Productivity
If miniaturization is pursued to meet performance requirements, then device performance improves, but hot carrier injection effects worsen
Solution Approach 1:
The multi-layer gate spacer structure is designed in advance to counteract hot carrier injection effects before they can occur. The spacer layers create physical barriers and potential wells that prevent hot carriers from being injected into the gate oxide, addressing the harmful effect proactively rather than reactively
Solution Approach 2:
The gate spacer structure implements local quality enhancement by concentrating the anti-HCI measures specifically at the critical regions where hot carrier injection occurs. The different spacer layers are positioned and configured to provide targeted protection at the source/drain regions adjacent to the gate, rather than uniformly throughout the entire device
Data Source
AI summary
A semiconductor structure and a method for forming the same are provided. The semiconductor structure includes a substrate, a gate structure disposed on the substrate, and a source/drain disposed in the substrate at opposite sides of the gate structure. The gate structure includes a gate dielectric layer disposed on the substrate, a gate electrode disposed on the gate dielectric layer, first gate spacers disposed on opposite sidewalls of the gate electrode, and second gate spacers disposed on the first gate spacers. The first gate spacer each include a first spacer layer on the sidewall, a second spacer layer on the first spacer layer, and a third spacer layer on the second spacer layer. The second spacer layer and the third spacer layer each include a first portion extending along the sidewall and a second portion extending in a direction from the gate electrode to the source/drain.