Gate Dielectric-Preserving Gate Cut for FinFET Etch Isolation
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Solution Overview
Problem
Conventional gate cutting techniques for integrated circuits, particularly at advanced technology nodes, face challenges in densely packed feature environments, where lateral etching can damage surrounding source/drain features, leading to reduced reliability and yield.
Innovation Solution
The technique involves selectively removing a portion of the gate structure to preserve the gate dielectric, which acts as a barrier during etching, minimizing damage to nearby source/drain features and increasing etching selectivity to protect these critical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching processes are used to remove gate structures, then gate cutting is achieved, but lateral etching damages surrounding source/drain features
Solution Approach 1:
A mandrel structure is introduced as an intermediary element between the etching process and the gate structure. The mandrel serves as a protective barrier that prevents lateral etching from reaching and damaging the source/drain features while allowing the etching process to effectively remove the gate structure.
Solution Approach 2:
The mandrel structure is formed in advance before the etching process. This preliminary action establishes a protective barrier that will prevent harmful lateral etching during the subsequent gate removal process, ensuring source/drain feature integrity from the outset.
2Productivity
If complete gate stack removal is performed, then gate cutting is achieved, but source/drain features are damaged by lateral etching
Solution Approach 1:
The mandrel acts as a mediator that enables complete gate stack removal while protecting the source/drain features. It allows the etching process to proceed aggressively for productivity while the mandrel absorbs the lateral etching impact, preventing damage to critical source/drain structures.
Solution Approach 2:
The mandrel structure converts the potentially harmful lateral etching into a beneficial protective mechanism. The same lateral etching that would normally damage source/drain features is redirected to erode the mandrel instead, turning a harmful effect into a protective function.
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
This approach enhances the reliability and yield of FinFET devices by preventing lateral etching damage to source/drain features, ensuring the integrity of the gate dielectric and maintaining the functionality of the integrated circuit devices.
Implementation Method 1
conventional gate cutting techniques typically implement etching processes that completely (or substantially) remove an entire portion of a gate stack
Data Source
AI summary
Gate cutting techniques for integrated circuit devices, particularly for fin-like field effect transistor devices, are disclosed herein. An exemplary method includes receiving an integrated circuit device that includes a gate structure and performing a gate cut process to separate the gate structure into a first gate structure and a second gate structure. The gate cut process includes selectively removing a portion of the gate structure, such that a residual gate dielectric layer extends between the first gate structure and the second gate structure. In some implementations, the residual gate dielectric includes a high-k dielectric material. The method further includes forming a gate isolation region between the first gate structure and the second gate structure.