Substrate Gas Flow Sequencing for Deep Concave Step Coverage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge of improving step coverage performance in semiconductor devices with deep concave structures, where existing methods struggle to sufficiently supply gases to the lower portions of these structures while minimizing supply to the upper portions.
Innovation Solution
A substrate processing method involving the differential supply of process gases, where the transfer velocity of gases is controlled to be faster towards the edge region of the substrate compared to the central region, and a reactive gas is supplied to enhance film formation on the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a source gas is supplied toward a substrate together with a hydrogen-containing gas to improve step coverage performance, then gas supply to lower portions of concave structures is enhanced, but gas supply to upper portions of the substrate increases excessively
Solution Approach 1:
The gas supply process is segmented into multiple stages: first supplying source gas alone, then supplying source gas combined with hydrogen-containing gas, and finally supplying inert gas. This temporal segmentation allows different gas compositions to reach different regions of the substrate at different times, improving step coverage while controlling overall gas distribution.
Solution Approach 2:
The patent employs periodic action by alternating between different gas supply modes. The source gas is supplied periodically, followed by periodic supply of source gas with hydrogen-containing gas, and then inert gas for purging. This periodic variation in gas supply creates optimal conditions for film deposition in concave regions while preventing excessive gas accumulation in upper regions.
2Manufacturing precision
If the flow velocity of source gas is increased to reach lower portions of deep concave structures, then step coverage is improved, but the supply amount to upper portions increases
Solution Approach 1:
The patent applies local quality by creating different gas flow conditions for different regions of the substrate. The source gas flows preferentially into concave structures where it is needed, while the hydrogen-containing gas and inert gas help control the overall gas distribution. This localized gas supply optimization improves step coverage without requiring uniform high flow velocity across the entire substrate surface.
Solution Approach 2:
The patent changes gas flow parameters dynamically by adjusting the combination and flow rates of different gases at different stages. First source gas alone is supplied, then source gas with hydrogen-containing gas, and finally inert gas for purging. These parameter changes allow precise control of gas distribution, achieving good step coverage while maintaining ease of operation through systematic parameter adjustment.
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 improves the step coverage performance by ensuring adequate gas supply to the lower portions of concave structures, enhancing film formation and reducing gas supply to the upper portions, thereby optimizing the film deposition process.
Implementation Method 1
supplying a first process gas such that a transfer velocity of the first process gas toward an edge region of a substrate is faster than the transfer velocity of the first process gas toward a central region of the substrate
Implementation Method 2
supplying a reactive gas toward the substrate
Data Source
AI summary
There is provided a technique capable of improving a step coverage performance of a film formed on a substrate. According to one aspect thereof, there is provided a substrate processing method including: (a1) supplying a first process gas such that a transfer velocity of the first process gas toward an edge region of a substrate is faster than the transfer velocity of the first process gas toward a central region of the substrate; (a2) supplying a second process gas such that a transfer velocity of the second process gas toward the central region of the substrate is faster than the transfer velocity of the second process gas toward the edge region of the substrate; and (b) supplying a reactive gas toward the substrate.