Selective Silicon Oxide Etching Using HF Adsorption and Inert Plasma
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for selective etching of substrates with silicon oxide films face issues of clogging due to residual fluorocarbon buildup, which affects the processing efficiency and requires frequent cleaning.
Innovation Solution
A method involving the adsorption of hydrogen fluoride on a substrate followed by exposure to plasma generated from an inert gas, allowing for selective etching of silicon oxide films with respect to other films without the need for fluorocarbon deposition, thereby reducing clogging and improving processing throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fluorocarbon deposition process is used before etching, then selective etching of silicon oxide film is achieved, but clogging occurs due to residual CF buildup on substrate surface
Solution Approach 1:
The patent removes the fluorocarbon deposition step from the conventional process sequence. Instead of depositing CF before etching, the process directly performs etching using a fluorocarbon-based plasma, eliminating the source of residual CF buildup that causes clogging while maintaining selective etching capability through optimized plasma parameters
Solution Approach 2:
The patent changes the process parameters by eliminating the deposition phase and using only etching phase with specific fluorocarbon gas composition and plasma conditions. This parameter change allows direct selective etching without generating the harmful residual CF deposits that occur in the conventional deposit-etch cycle
2Manufacturing precision
If conventional etching process with fluorocarbon deposition is used, then silicon oxide film can be etched, but processing throughput decreases due to frequent chamber cleaning requirements
Solution Approach 1:
By removing the fluorocarbon deposition step from the process, the patent eliminates the primary source of chamber contamination. This extraction of the problematic step maintains etching selectivity through direct plasma etching while significantly reducing the frequency of required chamber cleanings, thereby improving processing throughput
Solution Approach 2:
The patent discards the fluorocarbon deposition step that generates harmful residues. By using only the etching step with optimized fluorocarbon plasma, the process achieves the necessary selectivity without generating excessive deposits that would require frequent chamber maintenance, thus recovering lost productivity
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 achieves highly selective etching equivalent to Atomic Layer Epitaxy, reduces clogging, and lowers the frequency of chamber cleaning, enhancing processing efficiency and throughput.
Implementation Method 1
adsorbing hydrogen fluoride on the substrate
Implementation Method 2
exposing the substrate with the absorbed hydrogen fluoride to plasma generated from an inert gas to selectively etch the first region with respect to the second region
Data Source
AI summary
A method including providing a substrate in a process chamber of a substrate processing apparatus, the substrate having a first region containing a silicon oxide film and a second region containing a film other than the silicon oxide film; adsorbing hydrogen fluoride on the substrate; and exposing the substrate with the absorbed hydrogen fluoride to plasma generated from an inert gas to selectively etch the first region with respect to the second region.