Substrate Processing Method for Selective Metal Film Formation
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Solution Overview
Problem
Existing substrate processing techniques face challenges in selectively processing materials on semiconductor wafers with multiple exposed layers, particularly in preventing the corrosion of metals like copper and cobalt during etching, which leads to unwanted removal of these materials.
Innovation Solution
A substrate processing method involving a deoxidized atmosphere maintenance, selective film formation using sulfur-containing materials like thiol or disulfide on the surface of metals, followed by etching and film removal using reducing agents, ensures protection of the metal layers during processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a film forming material is supplied to form a film on the surface of the first material (metal), then the metal surface is protected during surface treatment, but the film must be removed afterward adding processing steps
Solution Approach 1:
A film forming material acts as an intermediary protective layer between the metal surface and the surface treatment process. The film is selectively formed on the metal (first material) using sulfur-containing compounds that bind to metal surfaces, protecting the metal during subsequent etching or other surface treatments of the second material. After treatment, the film is removed using reducing agents or other removal processes, completing the protective cycle without permanent addition of complexity to the substrate structure.
2Reliability
If the atmosphere is maintained in a deoxidized state, then oxidation of metal surfaces is prevented, but additional atmosphere control equipment and procedures are required
Solution Approach 1:
The patent employs a deoxidized atmosphere environment during the film forming process to prevent oxidation of the metal surface. By maintaining an inert or reducing atmosphere (low oxygen content) in the processing chamber, the metal surface remains in its reduced state, allowing the film forming material to bind effectively without competing oxidation reactions. This atmosphere control is integrated into the existing processing equipment, using standard vacuum or gas flow control mechanisms already present in semiconductor fabrication tools.
3Manufacturing precision
If selective film formation is performed on the first material only, then the second material can be processed without affecting the first material, but the film forming material must be highly selective
Solution Approach 1:
The film forming material exhibits local quality by selectively binding to the metal surface (first material) based on its specific chemical properties. Sulfur-containing compounds have high affinity for metal surfaces, forming strong metal-sulfur bonds that create the protective film. This selective binding occurs only on the metal regions, leaving other materials (second material) unaffected. The local chemical interaction between the film forming material and metal surface provides the selectivity needed, without requiring complex material engineering.
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 effectively prevents the corrosion of metals like copper and cobalt during etching, allowing for precise and selective processing of semiconductor wafers by forming a protective film that can be easily removed, thereby improving the selectivity and efficiency of the surface treatment.
Implementation Method 1
a film forming material, which selectively forms a film with respect to the first material and the second material, is supplied to the surface of the substrate
Implementation Method 2
the film is removed from the surface of the first material after the surface treatment step
Data Source
AI summary
A substrate processing method includes: maintaining an atmosphere in contact with at least a surface of a substrate on which a first material that is a metal and a second material that is a material other than the first material are exposed, as a deoxidized atmosphere; supplying a film forming material, which selectively forms a film on the first material among the first material and the second material, to the surface of the substrate in a state where the deoxidized atmosphere is maintained by the maintaining; performing a surface treatment of the second material in a state where the film is formed on a surface of the first material supplied in the supplying the film forming material; and removing the film from the surface of the first material after the performing the surface treatment.