FCVD Gap Fill Tuning for Void-Free Trench and Channel Filling
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Solution Overview
Problem
Existing film deposition processes struggle to simultaneously fill high aspect ratio trenches and lateral channels in 3D semiconductor structures without defects, such as void formation and non-uniform thickness, leading to reliability and manufacturing issues.
Innovation Solution
A tunable flowable chemical vapor deposition (FCVD) process combined with a bias plasma treatment is used to deposit films that flow into channels and are then solidified, ensuring uniform thickness and void-free filling of both vertical trenches and horizontal channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conformal deposition processes (e.g., ALD) are used to fill high aspect ratio trenches, then trench filling is improved, but lateral channel filling defects occur leading to reliability issues
Solution Approach 1:
The patent changes the deposition parameters by using flowable CVD conditions with controlled temperature and pressure to achieve a balance between conformal trench filling and complete lateral channel filling, avoiding the defects associated with traditional ALD processes
Solution Approach 2:
The patent employs a dynamic deposition process where the film is deposited in a flowable state that can adapt to the complex 3D geometry, allowing the material to flow into lateral channels while maintaining trench filling, then solidified in situ to lock the desired morphology
2Reliability
If less conformal processes are used to fill trenches, then lateral channel filling is improved, but trench pinch-off occurs leading to void formation
Solution Approach 1:
The patent modifies deposition parameters including temperature, pressure, and precursor flow rates to achieve a flowable deposition regime that prevents trench pinch-off while ensuring complete lateral channel filling, eliminating void formation
Solution Approach 2:
The patent uses a flowable film state as an intermediary that allows the material to navigate complex 3D geometries including both trenches and lateral channels, then solidifies in situ to preserve the complete filling morphology without voids
3Device complexity
If pitch non-uniformity between fins is present, then manufacturing complexity increases, but film thickness uniformity at trench bottoms deteriorates
Solution Approach 1:
The patent uses a dynamic flowable deposition process that adapts to varying fin pitches, allowing the material to flow and self-level at trench bottoms regardless of pitch non-uniformity, achieving uniform film thickness that simplifies subsequent etching 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 method achieves reliable and efficient filling of both trench and channel structures with uniform film thickness, reducing manufacturing complexity and enhancing the reliability of semiconductor devices.
Implementation Method 1
treating the film with a bias plasma treatment to solidify a portion of the film outside of the channel
Implementation Method 2
flowable chemical vapor deposition (FCVD) processes
Data Source
AI summary
Embodiments disclosed herein include a method for forming a film over a substrate. In an embodiment, the method comprises providing the substrate wherein the substrate comprises a trench and a channel into a sidewall of the trench, and disposing the film over the substrate. In an embodiment, the film flows into the channel and is disposed along the sidewall of the trench. In an embodiment, the method further comprises treating the film with a bias plasma treatment to solidify a portion of the film outside of the channel.