Flowable Dielectric Films Using Alternative Silicon Precursors
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Solution Overview
Problem
The challenge in semiconductor manufacturing lies in filling gaps and trenches with dielectric materials in high aspect ratio structures without creating voids or seams, which affects the quality and consistency of the dielectric films, leading to inferior device performance due to electrical crosstalk and charge leakage.
Innovation Solution
A method involving chemical vapor deposition (CVD) of silicon-and-nitrogen-containing materials using a silicon-containing precursor that reacts with radical nitrogen precursors generated in a remote plasma, followed by post-deposition annealing to convert the film into silicon oxide, enhancing film densification and reducing void formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the deposition rate of dielectric material is slowed to improve conformality and reduce void formation, then the quality of dielectric fill is improved, but the deposition time increases which reduces processing efficiency
Solution Approach 1:
The invention changes the chemical parameters of the deposition process by using alternative silicon precursors (such as silane, disilane, or polysilane) instead of conventional precursors. This chemical parameter change enables the deposition of highly flowable dielectric materials that can fill high aspect ratio trenches quickly without forming voids, thus improving both fill quality and processing efficiency simultaneously
Solution Approach 2:
The invention employs composite dielectric materials formed from silicon precursors containing multiple silicon atoms (disilane, polysilane) combined with organic groups. These composite materials provide both the flowability needed for complete trench filling and the structural integrity required for high-quality dielectric films, resolving the contradiction between fill quality and processing efficiency
2Stability of the object's composition
If conventional SOG films are used to increase flowability for better trench filling, then conformality is improved, but film density decreases due to residual carbon and silanol groups
Solution Approach 1:
The invention changes the compositional parameters by using silicon precursors with different chemical structures (disilane, polysilane) that inherently produce denser films upon oxidation. The resulting dielectric films have reduced residual carbon and silanol groups compared to conventional SOG films, achieving both good conformality and high film density
Solution Approach 2:
The invention employs accelerated oxidation processes (such as steam oxidation or plasma oxidation) to completely oxidize the silicon-containing precursors. This strong oxidation removes residual carbon and silanol groups more effectively, transforming the as-deposited films into dense, high-quality silicon oxide films while maintaining the flowability benefits
3Manufacturing precision
If high-temperature annealing is used to densify SOG films and remove residual carbon, then film density is improved, but volumetric shrinkage occurs which creates voids in narrow trenches
Solution Approach 1:
The invention changes the thermal parameters by using lower temperature annealing processes (below 400°C) combined with oxidation. This alternative thermal regime achieves film densification and carbon removal without the severe volumetric shrinkage that occurs in conventional high-temperature annealing, preventing void formation in narrow trenches while still improving film density
Solution Approach 2:
The invention introduces oxygen (through oxidation processes) as an intermediary that facilitates film densification without requiring high-temperature thermal shrinkage. The oxidation process consolidates the film structure and removes carbon impurities through chemical reactions rather than thermal contraction, thereby avoiding void formation while achieving the desired density improvement
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 approach results in high-quality, dense silicon oxide films that effectively fill trenches without voids, improving device performance by minimizing electrical noise and leakage, while maintaining high processing efficiency.
Implementation Method 1
chemical vapor deposition (CVD) of silicon-and-nitrogen-containing material formed from a silicon-containing precursor that reacts with a radical nitrogen precursor generated in a remote plasma
Implementation Method 2
radical nitrogen precursor generated in a remote plasma
Implementation Method 3
cured to convert the silicon-and-nitrogen-containing material to silicon oxide, increasing film densification during a post-deposition anneal
Implementation Method 4
convert the silicon-and-nitrogen-containing material to silicon oxide
Data Source
AI summary
Methods of depositing initially flowable dielectric films on substrates are described. The methods include introducing silicon-containing precursor to a deposition chamber that contains the substrate. The methods further include generating at least one excited precursor, such as radical nitrogen or oxygen precursor, with a remote plasma system located outside the deposition chamber. The excited precursor is also introduced to the deposition chamber, where it reacts with the silicon-containing precursor in a reaction zone deposits the initially flowable film on the substrate. The flowable film may be treated in, for example, a steam environment to form a silicon oxide film.