Pulsed RF Silicon Nitride Gap Fill With Fewer Micropores
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in achieving uniform thin-film quality, particularly with silicon nitride films, due to issues like micropore generation and non-uniformity during plasma-enhanced chemical vapor deposition (PECVD) processes, which affect the yield and quality of semiconductor devices.
Innovation Solution
A substrate processing method involving the use of pulsed radio frequency (RF) power to deposit silicon nitride films, with a duty ratio of RF power between 10% to 50%, and converting these films into densified silicon oxide films using remote oxygen plasma, to minimize micropore generation and enhance film uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma is used to promote chemical reaction and form silicon oxide film quickly, then deposition speed is improved, but micropores are generated in the film
Solution Approach 1:
The patent applies periodic pulsed plasma treatment where plasma is applied intermittently rather than continuously. The plasma is turned on and off in cycles, allowing the film to be deposited in controlled increments. This periodic action prevents continuous polymerization that leads to micropore formation, while still achieving acceptable deposition speeds through repeated cycles of plasma activation and thermal processing.
2Productivity
If plasma is used as energy source for chemical reaction, then reaction promotion is improved, but underlayer is damaged due to ion bombardment
Solution Approach 1:
The pulsed plasma treatment allows plasma to be applied only during specific time intervals rather than continuously. During the plasma-off periods, ion bombardment ceases, giving the underlayer time to recover and preventing cumulative damage. The plasma-on periods provide the necessary chemical reaction promotion, achieving a balance between reaction promotion and underlayer protection through temporal separation of these competing effects.
3Duration of action of moving object
If long plasma on-time is used for flowable nitride film deposition, then continuous reaction occurs, but formation of small oligomers is limited and unwanted polymers are formed
Solution Approach 1:
The patent implements periodic pulsed plasma where the plasma is turned on for limited intervals followed by off periods. This prevents continuous reaction that would deplete oligomer precursors and lead to unwanted polymer formation. The intermittent plasma activation maintains optimal oligomer concentration in the vapor phase, ensuring continuous formation of small oligomers that are essential for high-quality thin film deposition.
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 effectively reduces micropore formation and improves the uniformity of silicon nitride and silicon oxide films, leading to better gap-fill capabilities and increased yield in semiconductor manufacturing by preventing polymerization and ion bombardment damage.
Implementation Method 1
maintaining an inside of the reaction space in a plasma state by applying radio frequency (RF) power in a pulsed mode
Implementation Method 2
depositing a flowable silicon nitride film on the substrate... by using pulsed radio frequency (RF) power
Implementation Method 3
converting these films into densified silicon oxide films using remote oxygen plasma
Data Source
AI summary
A substrate processing method includes providing a substrate having a gap structure into a reaction space, and supplying a silicon precursor and nitrogen reactant gas into the reaction space, and depositing a flowable silicon nitride film on the substrate to fill at least a part of the gap of the substrate, while maintaining an inside of the reaction space in a plasma state by applying radio frequency (RF) power in a pulsed mode, wherein as a duty ratio of the RF power decreases, fewer micropores are generated in the silicon nitride film in the gap.