TiN Gapfill Deposition for Seam-Free 3D Semiconductor Trenches
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Solution Overview
Problem
There is a need to improve the gapfill processes for 3D semiconductor structures like finFETs and GAA devices to prevent the formation of seams and voids in titanium nitride (TiN) films.
Innovation Solution
A method involving the conformal deposition of multiple titanium nitride (TiN) layers, with the use of a blocking compound to form a blocking layer, allowing for selective deposition within trenches, thereby avoiding seam formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single TiN layer is deposited conformally on 3D structures, then the deposition process is simple and fast, but seams and voids form in the film
Solution Approach 1:
The patent divides the TiN film deposition into multiple sequential layers (first TiN layer, second TiN layer, third TiN layer) with intermediate blocking and removal steps. Each layer is deposited conformally but the multi-layer approach with blocking compound intervention prevents seam formation while maintaining overall deposition efficiency
Solution Approach 2:
The blocking layer is formed in advance on the first TiN layer before depositing the second TiN layer. This preliminary blocking action controls where subsequent material deposits, preventing seam formation at critical interfaces while allowing complete trench filling
2Manufacturing precision
If multiple TiN layers are deposited with blocking compound to prevent seams, then film continuity is improved, but the process complexity increases
Solution Approach 1:
The blocking compound acts as an intermediary layer between the first and second TiN layers. This intermediary controls the deposition process by preventing material accumulation at seam-prone locations, achieving continuous films through a manageable intermediate step rather than complex process control
Solution Approach 2:
The blocking layer is temporarily formed to control the deposition process, then completely removed after serving its purpose. This temporary structure enables precise control over film continuity without leaving residual complexity in the final device 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
The method effectively fills trenches in 3D semiconductor structures with a seamless and void-free titanium nitride gapfill material, enhancing the structural integrity and performance of these devices.
Implementation Method 1
exposing the plurality of nanosheets having the first TiN layer thereon to a blocking compound to form a blocking layer on a portion of the first TiN layer
Implementation Method 2
forming a second titanium nitride (TiN) layer to fill a portion of the trench, the second TiN layer growing from within the trench
Data Source
AI summary
One or more embodiments of the disclosure are directed to methods of forming structures that are useful for FEOL and BEOL processes. Embodiments of the present disclosure advantageously provide methods of depositing titanium nitride (TiN) in high aspect ratio (AR) structures with small dimensions. Some embodiments advantageously provide seam-free high-quality TiN films to fill high AR trenches with small dimensions. Embodiments of the present disclosure advantageously provide methods of filling 3D structures, such as finFETs, GAAs, and the like, without creating a seam. The methods include selective deposition processes using blocking compounds in order to provide seam-free TiN gapfill in 3D structures, such as GAA devices.