SiC Schottky Junction Defect Isolation via Insulating Film
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Solution Overview
Problem
Semiconductor substrates such as silicon carbide (SiC) and gallium nitride (GaN) often contain crystal defects, leading to increased leak currents and decreased yield, particularly in large-area Schottky junction devices, due to the presence of defects like micropipes and other crystal imperfections.
Innovation Solution
A semiconductor device and manufacturing method that involve identifying and isolating defect regions on the substrate using testing conductor films to measure electric characteristics, then forming insulating films and conductor films to electrically disconnect the defective areas, ensuring current flows through defect-free regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the area of the semiconductor device is increased to achieve larger Schottky junctions, then the device performance is improved, but the probability of containing crystal defects is increased, leading to decreased yield
Solution Approach 1:
The patent applies preliminary action by measuring electric characteristics of the semiconductor substrate before forming the Schottky junction, using testing conductor films to identify defect regions in advance. This allows defect regions to be specified and isolated before the main device fabrication, preventing crystal defects from compromising the large-area Schottky junction and maintaining high yield despite increased device area.
2Ease of manufacture
If the semiconductor substrate contains crystal defects, then the substrate can be used for device fabrication, but leak current occurs and device characteristics are deteriorated
Solution Approach 1:
The patent extracts the harmful defect regions from the semiconductor substrate by specifying their locations through electric characteristic measurements and then forming insulating films to isolate these regions. This removes the source of leak current while preserving the usable areas of the substrate, allowing continuous manufacture of reliable devices without discarding substrates containing defects.
Solution Approach 2:
The patent applies local quality by forming insulating films specifically in the identified defect regions rather than uniformly across the entire substrate. This localized treatment isolates crystal defects that cause leak current while maintaining the electrical characteristics of defect-free regions, thereby preserving overall device performance while enabling substrate reuse.
3Reliability
If testing and isolation procedures are added to eliminate crystal defects, then device reliability is improved, but manufacturing process complexity is increased
Solution Approach 1:
The patent applies universality by designing the testing conductor films to serve multiple functions: they act as both measurement probes for detecting defect regions and as part of the final device structure. This multi-functionality integrates the defect detection and isolation process into the existing manufacturing flow without adding separate complex testing equipment or procedures, thereby improving reliability while minimizing increases in manufacturing complexity.
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 effectively suppresses yield decreases caused by crystal defects, maintaining good electric characteristics and preventing short circuits in semiconductor devices, especially for large-area Schottky junctions.
Implementation Method 1
a first insulating film that coats the defect region and is arranged on the semiconductor substrate
Implementation Method 2
a conductor film that electrically connects to a principal surface of the semiconductor substrate
Data Source
AI summary
A semiconductor device includes a semiconductor substrate that is made of either of silicon carbide (SiC) and gallium nitride (GaN), and has a defect region containing a crystal defect; a first insulating film that coats the defect region and is arranged on the semiconductor substrate; and a conductor film that electrically connects to a principal surface of the semiconductor substrate, the principal surface being exposed to a region that is not coated with the first insulating film.