Flowable CVD Film Surface Roughness Control
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Solution Overview
Problem
Conventional methods for depositing flowable chemical vapor deposition (CVD) films struggle to achieve smooth and uniform surfaces, especially in high aspect ratio trenches, leading to void formation and pinching-off, which is critical for microelectronics device fabrication where high-quality films with low leakage are required.
Innovation Solution
A process involving pre-treatment of the substrate with plasma followed by exposure to trisilylamine (TSA) and ammonia (NH3), with optional oxygen, to form a flowable CVD film that is then cured, ensuring a smooth and uniform deposition across high aspect ratio features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional PECVD is used to deposit dielectric films on narrow trenches, then the film deposition speed is maintained, but the plasma cannot penetrate into deep trenches resulting in mushroom shape formation and voids at the bottom
Solution Approach 1:
The substrate surface is pre-treated with plasma before the main FCVD deposition to create a smooth initial surface and activate the substrate. This preliminary action prepares the surface to receive the flowable precursor uniformly, enabling better penetration and distribution into high aspect ratio trenches before the actual film formation begins
Solution Approach 2:
The patent replaces conventional plasma-enhanced CVD with flowable CVD that uses liquid precursor flow instead of plasma to deposit films in high aspect ratio trenches. The liquid precursor can flow and penetrate deep trenches more effectively than plasma, eliminating the mushroom shape problem while maintaining deposition capability
2Stability of the object's composition
If curing methods are applied to as-deposited FCVD films in high aspect ratio structures, then the film is solidified, but the process becomes difficult resulting in varying composition throughout the trench
Solution Approach 1:
The substrate surface is pre-treated with plasma to create a uniform, activated surface that promotes consistent precursor deposition and uniform film formation from the beginning. This preliminary preparation reduces the need for complex post-deposition curing to achieve composition uniformity throughout high aspect ratio trenches
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 significantly improves surface roughness and gap fill performance, enabling seamless filling of high aspect ratio structures with minimal seam formation, as demonstrated by atomic force microscopy showing at least three to four times improved roughness.
Implementation Method 1
pre-treating a substrate surface with a plasma to form a smooth pre-treated substrate surface
Implementation Method 2
forming a flowable CVD film on the pre-treated substrate surface by exposing the pre-treated substrate surface to a precursor and a reactant
Implementation Method 3
curing the flowable CVD film
Data Source
AI summary
Methods for forming a smooth ultra-thin flowable CVD film by using a surface treatment on a substrate surface before flowable CVD film deposition improves the uniformity and overall film smoothness. The flowable CVD film can be cured by any suitable curing process to form a smooth flowable CVD film.