Catalyst-Referred Etching for SiC and GaN Planarization
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Solution Overview
Problem
Conventional planarization techniques for semiconductor devices using hard materials like silicon carbide (SiC) and gallium nitride (GaN) face issues such as insufficient polishing rate, in-plane uniformity degradation, and increased crystal defects.
Innovation Solution
A substrate processing method involving ion implantation of specific materials to weaken crystal binding, followed by thermal treatment and chemical etching using a catalyst-referred etching method, which modifies the surface and allows for efficient planarization without mechanical polishing, thereby reducing crystal defects and improving processing speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional CMP (Chemical Mechanical Polishing) method is used to planarize hard materials like SiC and GaN, then the surface can be flattened, but the polishing rate is insufficient and processing time increases
Solution Approach 1:
The patent replaces the mechanical polishing system (CMP method) with a chemical etching system using catalyst-referred etching. The catalyst particles selectively catalyze the etching reaction on the hard material surface, enabling chemical removal of SiC and GaN without mechanical contact, thereby achieving high etching rates while avoiding mechanical damage and time-consuming processes
Solution Approach 2:
The patent changes the physical-chemical parameters of the hard material surface by introducing catalyst particles that modify the surface reactivity. The catalyst particles (e.g., Pt, Pd, Au) change the etching rate parameter locally, creating high-speed etching regions that dramatically increase the overall polishing rate compared to conventional CMP
2Manufacturing precision
If conventional CMP method is used for planarization, then the surface can be flattened, but in-plane uniformity of the materials degrades
Solution Approach 1:
The patent applies local quality by distributing catalyst particles with specific size ranges (0.1-10 μm) across the surface, where each catalyst particle creates a localized high-etching-rate zone. The varying sizes and distributions of catalyst particles enable selective etching that maintains in-plane uniformity by compensating for surface variations through localized chemical reactions rather than uniform mechanical pressure
3Reliability
If conventional CMP method is used to planarize hard materials, then the surface can be flattened, but crystal defects increase in the materials
Solution Approach 1:
The patent replaces mechanical polishing with chemical etching using catalyst particles, eliminating mechanical contact that causes crystal defects. The chemical reaction selectively removes material through bond breaking at the catalyst sites without the mechanical stress, friction, and heat generation inherent in CMP, thereby preserving crystal quality while maintaining planarization efficiency
Solution Approach 2:
The catalyst particles serve as intermediaries that facilitate the etching reaction without being consumed. They mediate between the etchant solution and the hard material surface, enabling selective material removal through chemical bonds breaking while protecting the underlying crystal structure from mechanical damage
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 planarizes hard materials like SiC and GaN, reducing crystal defects and enabling the production of semiconductor devices with low on-resistance and high breakdown voltage at a lower cost, while maintaining high processing efficiency.
Implementation Method 1
a first material is implanted into a surface of a target film to modify the surface of the target film
Implementation Method 2
by bringing a catalytic material close to the surface of the target film or by contacting the catalytic material to the surface of the target film while supplying a process solution
Data Source
AI summary
In a substrate processing method according to the embodiment, a first material is implanted into a surface of a target film to modify the surface of the target film. The surface of the target film is dissolved to remove the surface of the target film by bringing a catalytic material close to the surface of the target film or by contacting the catalytic material to the surface of the target film while supplying a process solution on the surface of the target film which has been modified.