Gate Stack Spacer Structure for TZDB-Resistant Scaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing demand for higher integration density in semiconductor devices leads to the need for reduced pattern linewidths, which in turn increases complexity and cost, and existing technologies struggle to efficiently achieve this without compromising reliability.
Innovation Solution
A semiconductor device design featuring a gate stack with a first and second dielectric layer, where the second dielectric layer has a higher dielectric constant than the first, and a spacer structure with spacers of varying dielectric constants to reduce complexity and cost while maintaining reliability, including a third spacer that fills a concave portion of the first dielectric layer to enhance time-zero dielectric breakdown properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If pattern linewidths are reduced to increase integration density, then integration density is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The spacer structure is divided into multiple segments (first spacer, second spacer, third spacer) with different dielectric constants, where each segment serves a specific function: the first and second spacers provide basic spacing and isolation, while the third spacer with lower dielectric constant specifically addresses TZDB concerns in the concave portion region, allowing complex functionality to be achieved through modular composition
Solution Approach 2:
Different regions of the spacer structure are assigned different dielectric constants based on local requirements: higher dielectric constant materials are used in regions where electrical isolation is critical, while lower dielectric constant material (third spacer) is placed in the concave portion where TZDB prevention is the priority, optimizing performance locally rather than uniformly
2Quantity of substance
If pattern linewidths are reduced to increase integration density, then integration density is improved, but manufacturing cost increases
Solution Approach 1:
The invention changes the dielectric constant parameter of the spacer materials, using a combination of high-k and low-k materials with specifically selected dielectric constants to achieve the desired electrical characteristics and TZDB protection, allowing standard manufacturing processes to be used without requiring expensive novel exposure technologies
3Device complexity
If simple spacer structure is used to reduce manufacturing complexity, then manufacturing complexity is reduced, but time-zero dielectric breakdown resistance deteriorates
Solution Approach 1:
The third spacer with lower dielectric constant is placed in advance in the concave portion region before final device operation, proactively preventing TZDB from occurring by establishing proper electrical field distribution and isolation in the most vulnerable area before any stress is applied
Solution Approach 2:
The spacer structure uses a composite of multiple dielectric materials with different properties (different dielectric constants), combining the advantages of high-k materials for electrical isolation with low-k materials for TZDB protection, achieving enhanced reliability without significantly increasing manufacturing complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves high reliability, reduced fabrication complexity, and lower costs by optimizing the dielectric layers and spacer structure, thereby improving integration density without the need for expensive exposure technologies.
Implementation Method 1
the gate insulating layer including a first dielectric layer and a second dielectric layer on the first dielectric layer, wherein a dielectric constant of the second dielectric layer is greater than a dielectric constant of the first dielectric layer
Implementation Method 2
a third spacer between the first spacer and the second spacer and filling at least a portion of the concave portion... wherein a dielectric constant of the second spacer is less than the dielectric constant of the first spacer and greater than a dielectric constant of the third spacer
Data Source
AI summary
A semiconductor device includes a gate stack including a gate insulating layer and a gate electrode on the gate insulating layer. The gate insulating layer includes a first dielectric layer and a second dielectric layer on the first dielectric layer, and a dielectric constant of the second dielectric layer is greater than a dielectric constant of the first dielectric layer. The semiconductor device also includes a first spacer on a side surface of the gate stack, and a second spacer on the first spacer, wherein the second spacer includes a protruding portion extending from a level lower than a lower surface of the first spacer towards the first dielectric layer, and a dielectric constant of the second spacer is greater than the dielectric constant of the first dielectric layer and less than a dielectric constant of the first spacer.