SiN Film Deposition in Recessed Patterns via Bottom-Up Filling
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Solution Overview
Problem
Conventional film deposition methods struggle to fill recessed patterns with high aspect ratios, such as trenches and via holes, without generating voids, as they tend to fill the upper portions more than the bottom, leading to incomplete filling and void formation.
Innovation Solution
A film deposition method involving cyclic adsorption of NH2 groups and N groups on a substrate surface, followed by silicon-containing gas adsorption, using specific plasma processes to selectively deposit a SiN film from the bottom up, ensuring uniform filling without blocking the opening of the recessed pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional film deposition methods are used to fill recessed patterns, then the upper portions are filled more quickly, but voids are generated due to incomplete filling of the bottom portions
Solution Approach 1:
The patent applies local quality by creating different surface states at different locations within the recessed pattern. NH2 groups are selectively formed at the bottom portions through ammonia plasma treatment, while the upper portions maintain different surface characteristics. This spatial variation in surface chemistry enables selective silicon-containing gas adsorption at the bottom, driving bottom-up filling that prevents void formation while maintaining high deposition productivity
2Productivity
If the recessed pattern is filled from the top, then deposition is faster, but the opening becomes blocked preventing complete filling
Solution Approach 1:
The patent inverts the conventional top-down filling approach by implementing bottom-up filling. Through selective NH2 group formation at the bottom portions and subsequent silicon-containing gas adsorption, the film grows upward from the recessed pattern bottom. This inversion prevents opening blockage and maintains process control throughout the filling operation, achieving both high deposition rate and complete filling
3Manufacturing precision
If uniform plasma treatment is applied across the substrate, then surface uniformity is improved, but selective bottom-up deposition cannot be achieved
Solution Approach 1:
The patent segments the plasma treatment process into distinct stages with different gases and conditions. First, ammonia plasma is used to selectively form NH2 groups at the bottom portions. Then, silicon-containing gas is introduced for selective adsorption. This segmentation of the deposition process enables both surface uniformity through controlled NH2 distribution and selective bottom-up deposition capability, resolving the contradiction between uniformity and adaptability
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 selective film deposition with superior bottom-up characteristics, preventing voids and ensuring complete filling of recessed patterns with a SiN film, enhancing the uniformity and effectiveness of the film deposition process.
Implementation Method 1
supplying a first process gas containing NH3 converted to first plasma to the surface of the substrate
Implementation Method 2
NH2 groups are caused to adsorb on a surface of a substrate
Implementation Method 3
supplying a second process gas containing N2 converted to second plasma to the surface of the substrate on which the NH2 groups is adsorbed
Implementation Method 4
The NH2 groups is partially converted to N groups
Implementation Method 5
A silicon-containing gas is caused to adsorb on the NH2 groups
Implementation Method 6
film deposition method for filling a recessed pattern formed in a surface of a substrate with a SiN film
Data Source
AI summary
A film deposition method for filling a recessed pattern with a SiN film is provided. NH2 groups are caused to adsorb on a surface of a substrate containing a recessed pattern formed in a top surface of the substrate by supplying a first process gas containing NH3 converted to first plasma to the surface of the substrate containing the recessed pattern. The NH2 groups is partially converted to N groups by supplying a second process gas containing N2 converted to second plasma to the surface of the substrate containing the recessed pattern on which the NH2 groups is adsorbed. A silicon-containing gas is caused to adsorb on the NH2 groups by supplying the silicon-containing gas to the surface of the substrate containing the recessed pattern on which the NH2 groups and the N groups are adsorbed. The above steps are cyclically repeated.