SiC MOSFET Insulating Film Nitrogen Gradient
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Solution Overview
Problem
Current semiconductor devices using silicon carbide (SiC) face limitations in achieving high field effect mobility due to suboptimal nitrogen concentration distribution in insulating films, which affects the initial breakdown voltage and reliability.
Innovation Solution
A semiconductor device design with a specific nitrogen concentration distribution in the insulating film, where the concentration peaks between 2 nm to 10 nm from the interface and decreases to half at 10 nm to 20 nm, enhancing field effect mobility by optimizing the bonding state and reducing defects at the interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If uniform nitrogen concentration is used in the insulating film, then manufacturing is simplified, but field effect mobility is suboptimal due to interface states
Solution Approach 1:
Rather than using a uniform nitrogen concentration throughout the insulating film, the patent implements local quality by concentrating nitrogen at the critical interface region (within 2-10 nm from the semiconductor region interface). This localized approach targets the specific area where interface states most affect field effect mobility, achieving optimal performance without requiring complex manufacturing processes.
Solution Approach 2:
The patent applies preliminary action by pre-positioning nitrogen atoms in the insulating film at the interface region before device operation. This is achieved through controlled nitridation processes that selectively introduce nitrogen at the desired location and concentration profile, preparing the insulating film to minimize interface states and maximize field effect mobility from the outset.
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
The optimized nitrogen concentration distribution in the insulating film improves field effect mobility by reducing interface states and increasing the driving ability of the MOSFET, resulting in better performance compared to reference examples.
Implementation Method 1
The insulating film contacts the first surface and the control electrode and includes nitrogen. The insulating film includes a first position and a second position along a first direction. The first direction is from the second semiconductor region toward the control electrode. The first position is disposed between the second position and the first surface in the first direction. A concentration of the nitrogen in the insulating film has a peak at the first position.
Data Source
AI summary
According to one embodiment, a semiconductor device includes a first semiconductor region, a second semiconductor region, a third semiconductor region, a first electrode, a second electrode, a control electrode and an insulating film. The first semiconductor region is of a first conductivity type and includes SiC. The second semiconductor region is provided on the first semiconductor region and has a first surface. The second semiconductor region is of a second conductivity type and includes SiC. The third semiconductor region is provided on the second semiconductor region, is of the first conductivity type and includes SiC. The first and second electrodes are electrically connected to the third semiconductor region. The control electrode is provided on the second semiconductor region. The insulating film is provided between the second semiconductor region and the control electrode. The insulating film contacts the first surface and the control electrode and includes nitrogen.