Semiconductor Plating Process Using Oxide Masking on SiC Surfaces
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Solution Overview
Problem
Conventional methods for manufacturing semiconductor devices using Ni/Au electroless plating on SiC surfaces incur labor and material costs for back-surface and outer peripheral tapes, and can lead to defects due to tape adhesion during subsequent processes.
Innovation Solution
A method involving thermal oxidation to form an oxide film on the back and side surfaces of the semiconductor substrate, allowing for electroless plating without the need for protective tapes, and subsequent removal of the oxide film to prevent plating deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If back-surface tape and outer peripheral tape are used to prevent plating deposition on SiC surfaces, then plating quality is improved, but labor costs and material costs increase
Solution Approach 1:
The patent applies preliminary action by forming an oxide film on the SiC substrate surface before the plating process. This oxide film is created through thermal oxidation treatment performed prior to plating, which pre-prevents plating deposition on areas where it should not occur, eliminating the need for protective tapes during the plating process.
Solution Approach 2:
The oxide film acts as an intermediary layer between the SiC substrate and the plating solution. This intermediate oxide film selectively prevents plating deposition on the SiC surface while allowing plating to proceed on the Al-Si electrode surface, thereby replacing the function of protective tapes without requiring them.
2Manufacturing precision
If back-surface tape and outer peripheral tape are used during plating, then plating deposition is controlled, but defects occur due to tape adhesion in subsequent processes
Solution Approach 1:
The patent extracts the protective function from the tape system and transfers it to the oxide film. By removing the tape component entirely and using only the oxide film formed on the SiC surface, the source of adhesion defects is eliminated while the plating deposition control function is maintained through the oxide film's selective barrier properties.
3Manufacturing precision
If protective tapes are applied and removed during manufacturing, then plating quality is maintained, but manufacturing time and labor increase
Solution Approach 1:
The oxide film is formed in advance through thermal oxidation treatment before plating, creating a permanent protective layer that remains in place during the plating process. This eliminates the need for applying and removing protective tapes, thereby reducing manufacturing steps and improving productivity while maintaining plating quality.
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
Reduces labor and material costs by eliminating the need for protective tapes, and prevents defects by ensuring no plating deposition on exposed SiC surfaces, enhancing plating quality and process reliability.
Implementation Method 1
performing thermal oxidation on the semiconductor substrate to form a gate insulating film
Implementation Method 2
depositing a polysilicon on the semiconductor substrate to form a plurality of gate electrodes
Data Source
AI summary
A method of manufacturing a semiconductor device includes: preparing semiconductor substrate having a front surface and a back surface opposite to each other, the semiconductor substrate being of a first conductivity type; forming a device structure in the semiconductor substrate, at the front surface; performing thermal oxidation to form a gate insulating film and depositing a polysilicon to form a plurality of gate electrodes; removing the polysilicon at the back surface of the semiconductor substrate while leaving an oxide film formed at the back surface and a side surface of the semiconductor substrate by the thermal oxidation; forming a surface electrode on the device structure; and forming a plating film on the surface electrode while continuing to leave the oxide film at the back surface and the side surface of the semiconductor substrate.