Water-Free Etching Liquid With Silicon Protection Layer Selectivity
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Solution Overview
Problem
Existing wet etching techniques for semiconductor manufacturing lack selectivity, as they often remove both metal-based and silicon-based materials, leading to unintended removal of silicon oxide films and metal sub-products.
Innovation Solution
A substrate processing method using an etching liquid containing a fluorine-based etching agent and a protection agent that reacts with silicon-based materials to form a protection layer, preventing etching of these materials while allowing etching of metal-based materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional wet etching is used to remove metal-based materials, then the metal-based materials are etched, but silicon-based materials are also unintentionally removed
Solution Approach 1:
The patent introduces a protection agent as an intermediary substance that selectively reacts with silicon-based materials to form a protection layer. This protection layer acts as a mediator between the etching liquid and the silicon-based materials, preventing the etching agent from directly contacting and removing the silicon oxide film, thereby achieving selective etching of metal-based materials only
Solution Approach 2:
The patent modifies the chemical composition parameters of the etching liquid by adding specific protection agents (such as silane-based compounds or silicon oxide-based compounds) to change the selectivity characteristics. This parameter change enables the etching liquid to differentiate between metal-based and silicon-based materials, allowing precise control over which materials are etched
2Manufacturing precision
If conventional etching liquid is used, then both metal-based and silicon-based materials are etched, but this leads to removal of critical layers
Solution Approach 1:
The protection agent serves as a protective intermediary that selectively bonds to silicon-based materials forming a protective barrier. This intermediary layer prevents the etching agent from attacking the silicon oxide film while allowing it to etch metal-based materials, thus preserving critical layers and improving process reliability
Solution Approach 2:
The protection agent is applied in advance to the silicon-based materials before the etching process. This preliminary action creates a protective layer that pre-empts and prevents the harmful etching effect from reaching the silicon oxide film, ensuring the critical layers are preserved during subsequent etching operations
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 selectivity of wet etching, allowing for the targeted removal of metal-based materials without etching silicon-based materials, thereby preserving critical layers in semiconductor manufacturing.
Implementation Method 1
a protection agent configured to react with the second material between the first material and the second material to form a protection layer on a surface of the second material
Implementation Method 2
an etching agent configured to etch a metal-based first material and a silicon-based second material exposed on the substrate
Data Source
AI summary
A substrate processing method includes holding a substrate; and supplying an etching liquid to the substrate held in the holding of the substrate. The etching liquid contains an etching agent configured to etch a metal-based first material and a silicon-based second material exposed on the substrate and a protection agent configured to react with the second material between the first material and the second material to form a protection layer on a surface of the second material. Here, the etching agent is a liquid which contains fluorine atoms and an organic solvent and substantially does not contain water, and the protection layer protects the second material from etching with the etching agent.