Conformal Silicon Nitride Deposition Without Mask Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The semiconductor industry faces challenges in selectively depositing silicon nitride films without using temporary mask structures, as dry mask removal processes can cause charge-induced damage and contamination, and wet chemical processes are less attractive due to particle control concerns.
Innovation Solution
A method involving selective thermal CVD and plasma nitridation processes to deposit conformal silicon nitride films on substrates with silicon oxide and non-silicon oxide surfaces, allowing for the formation of single or multi-layer silicon nitride films without the need for temporary mask structures, utilizing silane and nitrogen-containing gases in a PECVD system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If temporary mask structures are used for selective silicon nitride deposition, then selective deposition can be achieved, but mask removal processes cause charge-induced damage and contamination
Solution Approach 1:
The patent extracts and eliminates the temporary mask structure from the deposition process. Instead of using masks that require removal, the invention achieves selective deposition directly on the substrate through controlled PECVD processes, thereby removing the source of charge-induced damage and contamination associated with mask removal
Solution Approach 2:
The patent introduces an intermediary approach by using a carefully controlled deposition process with specific gas chemistry (silane and nitrogen-containing gases) and plasma conditions that enable selective silicon nitride formation without requiring physical mask structures, thus avoiding the harmful effects of mask removal
2Ease of manufacture
If wet chemical processes are used for mask removal, then masks can be removed, but particle control becomes problematic
Solution Approach 1:
The patent extracts the mask removal step entirely from the process by eliminating the need for temporary masks. The selective deposition is achieved through controlled PECVD parameters and gas chemistry, thereby removing the requirement for wet chemical processing and the associated particle control issues
3Quantity of substance
If conventional CVD or PECVD is used for silicon nitride deposition, then film formation is achieved, but temporary mask structures are required for selectivity
Solution Approach 1:
The patent extracts and eliminates the temporary mask structures from the conventional CVD/PECVD process. The invention achieves selective silicon nitride deposition by controlling plasma conditions, gas chemistry (silane and nitrogen-containing gases), and deposition parameters to enable direct selective formation on substrate surfaces without masks
Solution Approach 2:
The patent changes key process parameters including plasma power, pressure, gas flow rates, and temperature to enable selective deposition. By optimizing these parameters, the process achieves selective silicon nitride formation without requiring temporary mask structures, thereby reducing device complexity
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 enables efficient, conformal silicon nitride film deposition directly on substrates, reducing the risk of damage and contamination, and lowering costs by using low-cost precursor gases, while maintaining high deposition quality and throughput.
Implementation Method 1
depositing a first silicon film layer on the non-silicon oxide surface of the substrate
Implementation Method 2
nitriding the first silicon film layer to form a first silicon nitride film layer
Data Source
AI summary
The present disclosure generally relates to methods for forming silicon nitride film layers on substrates. In an embodiment, the method includes positioning a substrate having at least one feature thereon in a process chamber, depositing a first silicon film layer on a non-silicon oxide surface of the substrate for a time duration of about 1 to about minutes, nitriding the first silicon film layer to form a first silicon nitride film layer on the substrate, selectively depositing a second silicon film layer on the first silicon nitride film layer, and nitriding the second silicon film layer to form a second silicon nitride film layer disposed directly on the first silicon nitride film layer.