Embedded Fin Liner Endpoint for FinFET Reveal Control
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Solution Overview
Problem
Conventional FinFET fabrication techniques face challenges in controlling fin reveal depth, particularly in dense fin regions, leading to device variability.
Innovation Solution
Implementing a fin liner as an embedded endpoint layer to enhance control over fin reveal, using techniques such as self-aligned double patterning and anisotropic etching processes, and forming dielectric layers to achieve uniform fin height and isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional FinFET fabrication techniques are used, then manufacturing simplicity is maintained, but fin reveal depth control precision deteriorates leading to device variability
Solution Approach 1:
The fabrication process is segmented into multiple distinct stages: forming mandrels, depositing first dielectric layer, forming liner segments, depositing second dielectric layer, and selective removal. This segmentation allows precise control of fin reveal depth at each stage, particularly through the liner segment which acts as an embedded endpoint marker for etching processes.
Solution Approach 2:
Liner segments are formed in advance before the final fin reveal etching process. These pre-formed liner segments serve as preliminary markers that guide the subsequent etching depth, ensuring precise fin reveal control without requiring complex real-time monitoring during the etching process itself.
2Manufacturing precision
If fin liner as embedded endpoint layer is implemented, then fin reveal control precision is improved, but manufacturing complexity increases
Solution Approach 1:
The liner segments perform a self-service function by automatically serving as endpoint markers for the etching process. The etch process itself removes material until it reaches the liner segment, which then signals the endpoint. This self-regulating mechanism eliminates the need for external monitoring or complex control systems, simplifying manufacturing despite the additional process step.
Solution Approach 2:
The liner segment acts as an intermediary layer between the dielectric materials and the substrate. It mediates the etching process by providing a distinct interface that signals when the desired fin reveal depth is reached, translating the physical structure into a controllable process endpoint without requiring complex external intervention.
3Reliability
If multiple dielectric layers with liner segments are formed, then device reliability is improved through uniform fin height, but manufacturing time increases
Solution Approach 1:
Multiple functions are merged into the liner segment formation process: it serves as both a structural layer for isolation and an endpoint marker for etching control. The first and second dielectric layers are deposited in sequence with the liner segment embedded between them, combining isolation, structural support, and process control functions into a unified multi-layer structure that improves reliability without requiring separate process cycles for each 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 allows for precise control of fin reveal, reducing variability and improving the uniformity of FinFET structures, thereby enhancing the reliability and performance of semiconductor devices.
Implementation Method 1
using techniques such as self-aligned double patterning and anisotropic etching processes
Data Source
AI summary
A semiconductor structure is provided. The semiconductor structure includes a plurality of fins formed from a substrate, at least one liner segment formed along a portion of the substrate, a first dielectric layer formed on the substrate and bounded by the liner segment, and a second dielectric layer formed within an interior of the liner segment.