FinFET Fin Oxidation Prevention via Dielectric Liner Stack
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Solution Overview
Problem
FinFET devices face challenges in preventing oxidization during thermal anneal processes, which can lead to fin collapse and critical dimension loss, affecting the integration density and electrical performance of semiconductor devices.
Innovation Solution
A method involving the formation of a silicon capping layer and subsequent nitridation treatment to create a protective nitride film, combined with a dielectric liner stack, which provides structural support and isolates the fins from oxygen, reducing oxidization and preserving fin dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal anneal processes are performed on FinFET devices, then electrical performance can be improved, but fin oxidization and collapse occur leading to critical dimension loss
Solution Approach 1:
A dielectric liner stack comprising multiple layers (first dielectric layer, second dielectric layer, and third dielectric layer) is introduced as an intermediary protective structure between the fin and the oxidizing environment during thermal anneal processes. This liner stack acts as a barrier that prevents oxygen from reaching the fin surface, thereby preventing fin oxidization and collapse while allowing the thermal anneal process to proceed and improve electrical performance.
Solution Approach 2:
The dielectric liner stack is formed on the fin surface before the thermal anneal process is performed. This preliminary protective coating is deposited conformally over the fin structure, ensuring that the fin is protected from oxidization before exposure to high-temperature annealing conditions. The preliminary action of forming this protective barrier prevents the harmful effects of thermal processing.
2Productivity
If fin dimensions are reduced to increase integration density, then more components can be integrated, but fins become more susceptible to oxidization and collapse during thermal processing
Solution Approach 1:
A thin film dielectric liner stack is deposited conformally over the fin structure. This thin film provides protective coverage that prevents oxidization while accommodating the reduced dimensions of scaled fins. The conformal deposition ensures uniform protection across the entire fin surface, maintaining structural integrity even as fin dimensions are reduced to increase integration density.
Solution Approach 2:
The dielectric liner stack comprises multiple dielectric layers with different material compositions and properties. This composite structure provides enhanced protection compared to a single-layer approach, with each layer contributing specific properties such as oxidation resistance, stress management, and adhesion. The composite material approach ensures robust protection for scaled fins while maintaining compatibility with advanced manufacturing processes.
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 solution effectively prevents fin collapse and oxidization, maintaining fin dimensions and improving electrical performance by providing structural support and protecting the fins from oxygen during anneal processes.
Implementation Method 1
A method involving the formation of a silicon capping layer and subsequent nitridation treatment to create a protective nitride film
Implementation Method 2
which provides structural support and isolates the fins from oxygen, reducing oxidization and preserving fin dimensions during anneal processes
Implementation Method 3
isolates the fins from oxygen, reducing oxidization and preserving fin dimensions
Data Source
AI summary
A method includes forming a semiconductor capping layer over a first fin in a first region of a substrate, forming a dielectric layer over the semiconductor capping layer, and forming an insulation material over the dielectric layer, an upper surface of the insulation material extending further away from the substrate than an upper surface of the first fin. The method further incudes recessing the insulation material to expose a top portion of the first fin, and forming a gate structure over the top portion of the first fin.