Silicon Nitride Deposition Using Silazane Precursors for Gap Fill
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Solution Overview
Problem
Current methods for depositing silicon nitride films by chemical vapor deposition face challenges in achieving high N/S atomic ratios, leading to poor film quality and uniformity, especially in high aspect ratio trenches, due to the limitations of using trisilylamine as a precursor.
Innovation Solution
The method involves introducing silicon-nitrogen precursors and plasma-activated co-reactants into a processing chamber to produce a plasma, reacting them to form flowable silicon nitride materials, which are then treated to achieve solid silicon nitride films with higher N/S atomic ratios, suitable for gap-fill applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If trisilylamine (TSA) is used as precursor, then deposition process is simple, but N/S atomic ratio is limited to about 0.33
Solution Approach 1:
The patent changes the chemical parameters of the precursor material from TSA (N/S ratio 0.33) to silazane compounds with higher nitrogen content. This parameter change in the precursor composition enables achieving N/S atomic ratios greater than 0.33 while maintaining the CVD deposition process
Solution Approach 2:
The patent uses composite precursor systems combining silazane compounds with specific chemical formulas containing silicon, nitrogen, and hydrogen in controlled ratios. These composite molecular structures provide both the desired N/S ratio and the flowable properties needed for gap fill applications
2Manufacturing precision
If post treatment is used to increase nitrogen content, then N/S atomic ratio improves, but processing time and cost increase
Solution Approach 1:
The patent incorporates the nitrogen enrichment action into the deposition step itself by using silazane precursors with high nitrogen content. This preliminary incorporation of nitrogen during deposition eliminates the need for subsequent post-treatment steps to increase nitrogen content, reducing processing time
Solution Approach 2:
The patent removes the separate post-treatment step from the process flow by integrating the nitrogen enrichment function directly into the precursor selection and deposition process, thereby eliminating additional time and cost
3Manufacturing precision
If post treatment is used to increase nitrogen content, then nitrogen penetration improves, but film uniformity in high aspect ratio trenches deteriorates
Solution Approach 1:
The patent performs nitrogen incorporation during the deposition step itself rather than as a subsequent treatment. This preliminary action ensures uniform nitrogen distribution throughout the film as it forms, maintaining consistency in high aspect ratio trenches without the limitations of post-treatment penetration depth
4Ease of operation
If conventional precursors are used, then deposition is easier, but flowable properties and N/S ratio cannot be achieved simultaneously
Solution Approach 1:
The patent employs silazane compounds with specific composite molecular structures that simultaneously provide flowable properties for gap fill applications and high N/S atomic ratios. These composite precursors contain silicon, nitrogen, and hydrogen in configurations that enable both desired material properties
Solution Approach 2:
The patent changes the chemical parameters of the precursor to include silazane compounds with specific formulas that balance flowability and nitrogen content. This parameter optimization allows achieving both ease of deposition and high N/S ratio greater than 0.33
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, flowable films with low wet etch rates and low shrinkage, effectively filling gaps and improving film uniformity, particularly suitable for trench filling with superior characteristics compared to traditional methods.
Implementation Method 1
introducing one or more silicon-nitrogen precursors and one or more plasma-activated co-reactants into a processing chamber, producing a plasma within the processing chamber, and reacting the silicon-nitrogen precursor and the plasma-activated co-reactant in the plasma
Implementation Method 2
reacting the silicon-nitrogen precursor and the plasma-activated co-reactant in the plasma to produce a flowable silicon nitride material on a substrate within the processing chamber
Data Source
AI summary
Embodiments described and discussed herein provide methods for depositing silicon nitride materials by vapor deposition, such as by flowable chemical vapor deposition (FCVD), as well as for utilizing new silicon-nitrogen precursors for such deposition processes. The silicon nitride materials are deposited on substrates for gap fill applications, such as filling trenches formed in the substrate surfaces. In one or more embodiments, the method for depositing a silicon nitride film includes introducing one or more silicon-nitrogen precursors and one or more plasma-activated co-reactants into a processing chamber, producing a plasma within the processing chamber, and reacting the silicon-nitrogen precursor and the plasma-activated co-reactant in the plasma to produce a flowable silicon nitride material on a substrate within the processing chamber. The method also includes treating the flowable silicon nitride material to produce a solid silicon nitride material on the substrate.