Selective Substrate Etching With Cyclic Fluorine Deposit Removal
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Solution Overview
Problem
Existing substrate processing methods struggle to selectively protect a first region of a substrate while effectively etching a second region, particularly when the regions are formed from different materials like silicon nitride and silicon oxide.
Innovation Solution
A substrate processing method involving the formation of a first deposit on the first region and a second deposit containing fluorine on the second region, followed by the removal of the second deposit and part of the second region, with these steps repeated until a stop condition is satisfied.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fluorocarbon is deposited on both first and second regions for protection and etching, then the etching process can proceed, but selective protection of the first region while etching the second region becomes difficult to achieve
Solution Approach 1:
The patent applies local quality by making the first region have different surface properties than the second region. The first region is treated to be hydrophobic or have low surface energy, causing fluorocarbon to preferentially deposit there, while the second region remains hydrophilic with high surface energy, allowing selective protection and etching based on localized material properties
Solution Approach 2:
The patent segments the substrate into distinct first and second regions with different surface characteristics. By creating this segmentation in surface properties, the process enables selective fluorocarbon deposition on the first region while allowing etching of the second region, achieving spatial separation of protection and etching functions
2Manufacturing precision
If the etching process is made more selective, then the first region is better protected, but the etching rate of the second region decreases
Solution Approach 1:
The patent employs periodic action through alternating deposition and etching cycles. During deposition phases, fluorocarbon is deposited to protect the first region; during etching phases, the protected first region remains intact while the second region is etched. This periodic alternation maintains high selectivity while achieving the required etching depth through multiple iterations
Solution Approach 2:
The patent applies preliminary action by pre-depositing fluorocarbon on the first region before the etching process begins. This preliminary protection layer is formed in advance, ensuring the first region is protected before any etching occurs, and the layer is optimized to provide adequate protection throughout the subsequent etching cycles
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 allows for precise and selective etching of the second region while protecting the first region, achieving improved control over the etching process and enhancing the selectivity between different substrate regions.
Implementation Method 1
preferentially forming, by a substrate processing apparatus, a first deposit on the first region; forming, after (a), a second deposit on the second region, the second deposit containing fluorine
Data Source
AI summary
A substrate processing method is for processing a substrate that includes a first region and a second region with compositions different from each other. The substrate processing method includes (a) preferentially forming, by a substrate processing apparatus, a first deposit on the first region; (b) forming, after (a), a second deposit on the second region, the second deposit containing fluorine and the second deposit being different from the first deposit; and (c) removing, after (b), the second deposit and at least a part of the second region. The steps (a)-(c) are repeated, in order, in a case that a stop condition is not satisfied.