Semiconductor Electrode Formation via Surface Roughness Uniformization
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Solution Overview
Problem
In semiconductor devices, variations in ion injection amounts between different regions on a substrate lead to surface roughness differences, which are reflected in the electrode, making it difficult to distinguish between shadows and flaws during appearance inspections.
Innovation Solution
A method involving semiconductor region formation, hydrofluoric acid cleaning, surface roughness uniformization using APM cleaning, and electrode formation, where APM cleaning creates a thin oxide film to uniformize the surface roughness before electrode formation, ensuring consistent electrode quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If semiconductor regions with different ion injection amounts are formed on the substrate, then the desired device characteristics are achieved, but surface roughness variations occur between regions
Solution Approach 1:
A planarization layer is formed in advance over the semiconductor substrate before the electrode formation process. This preliminary action prevents the subsequent electrode layer from directly contacting the rough semiconductor surface, thereby eliminating the reflection of surface roughness variations in the final electrode structure while preserving the different ion injection amounts in the semiconductor regions.
Solution Approach 2:
The planarization layer serves as an intermediary between the semiconductor substrate with varying surface roughness and the electrode layer. This intermediate layer absorbs the surface irregularities and provides a uniform upper surface, preventing the transmission of roughness patterns to the electrode while allowing the underlying semiconductor regions to maintain their functional characteristics.
2Ease of manufacture
If electrodes are formed directly on semiconductor regions with different surface roughness, then the manufacturing process is simplified, but appearance inspection accuracy deteriorates due to shadow formation
Solution Approach 1:
The planarization layer is formed as a preliminary step before electrode deposition. This additional layer requires slightly more manufacturing steps but prevents the formation of shadows on the electrode surface, thereby enabling accurate appearance inspections to be performed without compromising overall process efficiency.
Solution Approach 2:
The planarization layer acts as a mediator that decouples the rough semiconductor surface from the electrode structure. By introducing this intermediate layer, the electrode surface becomes uniform and free from shadow artifacts, allowing inspection systems to accurately detect real defects without interference from surface roughness patterns.
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 surface roughness variations from being reflected in the electrode, enabling accurate appearance inspections by ensuring uniform surface roughness and consistent electrode formation.
Implementation Method 1
a cleaning using hydrofluoric acid is performed on the one principal surface of the semiconductor substrate
Implementation Method 2
the surface roughness of the one principal surface of the semiconductor substrate is uniformized
Data Source
AI summary
A method of manufacturing a semiconductor device includes a semiconductor region forming process, a cleaning process, a surface roughness uniformizing process, and an electrode forming process. As the semiconductor region forming process, semiconductor regions are formed such that a plurality of semiconductor regions with different ion injection amounts are exposed on one principal surface of a semiconductor substrate. As the cleaning process, after the semiconductor region forming process, a cleaning using hydrofluoric acid is performed on the one principal surface of the semiconductor substrate. As the surface roughness uniformizing process, after the cleaning process, the surface roughness of the one principal surface of the semiconductor substrate is uniformized. As the electrode forming process, after the surface roughness uniformizing process, electrodes are formed on the one principal surface of the semiconductor substrate.