Fin Isolation Structures for Void-Free Semiconductor Gap Fill
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Solution Overview
Problem
As semiconductor devices continue to integrate more components into a given area through reduced minimum feature sizes, challenges arise in forming seamless and void-free isolation structures to prevent shorting between neighboring source/drain regions, particularly in finFET devices with varying fin spacings.
Innovation Solution
A multi-layer dielectric material deposition and etching process is employed, utilizing flowable deposition techniques to form seamless isolation structures with varying widths and heights, ensuring gap-fill capability and minimal stress on the structure, thereby preventing defects and damage to underlying layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional deposition techniques are used to form isolation structures, then the process is simpler, but voids and seams appear in the isolation structures causing shorting between neighboring source/drain regions
Solution Approach 1:
The isolation structure is formed using multiple deposition steps with different dielectric materials (first dielectric material, second dielectric material, and third dielectric material) deposited in sequence. Each layer is deposited conformally and then planarized, creating a segmented structure that eliminates voids and seams while maintaining reliability.
Solution Approach 2:
The method performs preliminary actions by first depositing the first dielectric material conformally, then adding the second dielectric material, and finally adding the third dielectric material. Each deposition is followed by planarization to prepare the surface for the next layer, ensuring a void-free structure before proceeding to subsequent steps.
2Productivity
If feature sizes are reduced to increase integration density, then more components can be integrated, but forming seamless isolation structures becomes more difficult
Solution Approach 1:
The method changes material parameters by using three different dielectric materials with different properties. The first dielectric material has different characteristics than the second and third materials, allowing each layer to be optimized for specific requirements such as stress management, gap-filling, and adhesion, thereby maintaining manufacturing precision at reduced feature sizes.
Solution Approach 2:
The solution moves from a single-layer isolation structure to a multi-layer vertical structure. By adding the dimension of multiple deposited layers (first, second, and third dielectric materials) with varying thicknesses and properties, the method achieves seamless isolation even at reduced feature sizes, enabling higher integration density without sacrificing precision.
3Adaptability or versatility
If single-layer isolation structures are used, then the process is simpler, but the structures cannot accommodate varying fin spacings and create stress
Solution Approach 1:
The method applies local quality by making each dielectric layer have different properties and thicknesses tailored to specific requirements. The first dielectric material layer has a first thickness, the second layer has a second thickness, and the third layer has a third thickness. Each material is selected and deposited with specific local characteristics to accommodate varying fin spacings and manage stress in different regions of the structure.
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 method enables the formation of void-free isolation structures that maintain device integrity, reduce manufacturing defects, and enhance yield, while allowing for smaller feature sizes and reduced manufacturing costs.
Implementation Method 1
flowable deposition techniques to form seamless isolation structures
Data Source
AI summary
A semiconductor device and method of manufacture which utilize isolation structures between semiconductor regions is provided. In embodiments different isolation structures are formed between different fins in different regions with different spacings. Some of the isolation structures are formed using flowable processes. The use of such isolation structures helps to prevent damage while also allowing for a reduction in spacing between different fins of the devices.