Bilayer Cavity Spacers for Durable GAA Transistor Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing non-planar transistors, such as gate-all-around transistors, face challenges with conventional cavity spacers that are prone to erosion and damage during processing due to the use of low dielectric constant materials, which compromises their structural integrity and electrical isolation.
Innovation Solution
Implementing bilayer cavity spacers comprising a first low-k dielectric material layer and a second high-k dielectric material layer, where the high-k layer provides enhanced durability and protects the low-k layer during processing, ensuring robust electrical isolation between source and drain regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional low-k dielectric material is used for cavity spacers, then electrical isolation between source and drain regions is achieved, but structural integrity and durability during processing deteriorate due to erosion and damage
Solution Approach 1:
The cavity spacer is constructed as a composite structure with an inner low-k dielectric material layer providing electrical isolation and an outer high-k dielectric material layer providing mechanical strength and durability. This composite approach allows both electrical isolation and structural integrity to coexist without compromise.
Solution Approach 2:
The cavity spacer is divided into two distinct functional layers: an inner layer dedicated to electrical isolation properties and an outer layer dedicated to mechanical protection properties. This segmentation allows each layer to be optimized for its specific function without interfering with the other.
2Reliability
If bilayer cavity spacers are implemented, then durability and electrical isolation are enhanced, but device complexity increases
Solution Approach 1:
While segmentation into two layers increases structural complexity, it provides clear functional separation that simplifies the design rationale and allows independent optimization of each layer's properties for its specific purpose.
Solution Approach 2:
The composite bilayer structure, while more complex than a single layer, enables simultaneous achievement of durability and electrical isolation that would be impossible with a single material, justifying the increased complexity through superior performance.
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 bilayer cavity spacers enhance the durability and maintain effective electrical isolation, supporting faster transistor speeds and improved electrostatic control while withstanding processing steps, thereby improving the performance and reliability of nanoribbon-based transistors.
Implementation Method 1
cavity spacers formed between adjacent nanoribbons in the stack. The cavity spacers may include an inner layer with a low dielectric constant (low-k) and an outer layer with a high dielectric constant (high-k)
Data Source
AI summary
Described herein are nanoribbon transistors with bilayer cavity spacers deposited near the ends of the nanoribbons, including between the ends of adjacent nanoribbons. The cavity spacers include a first, inner layer next to the gate stack, and a second, outer layer next to the source or drain. The inner layer may be a low-k dielectric material, while the outer layer may be a high-k dielectric material.