SiC-SiO2 Interface Engineering with Nitrogen-Rich Transition Region
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In silicon carbide semiconductor devices, defects at the interface between the silicon carbide and silicon dioxide layers hinder performance, particularly in reducing defects and enhancing field-effect mobility.
Innovation Solution
A transition region with a high concentration of nitrogen, carbon, and oxygen is introduced between the silicon carbide and silicon dioxide layers, formed through a heat treatment process in an NO gas atmosphere, which increases nitrogen accumulation and reduces defects, thereby improving the device's electric characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a silicon dioxide layer is formed directly on a silicon carbide layer, then the device structure is simple, but defects occur at the interface between the layers
Solution Approach 1:
A transition region containing nitrogen is introduced between the silicon carbide layer and the silicon dioxide layer. This transition region acts as an intermediary layer that reduces defects at the interface, improving the overall interface quality without requiring direct contact between the silicon carbide and silicon dioxide layers.
Solution Approach 2:
The transition region is created with a specific local composition containing nitrogen at a concentration of 1.0×10^20 cm^-3 or higher, which is five or more times higher than the maximum nitrogen concentration in the silicon dioxide layer. This localized modification of composition and structure addresses the interface defect problem without changing the overall device structure.
2Reliability
If nitrogen concentration is increased in the transition region, then field-effect mobility is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The nitrogen concentration in the transition region is controlled to be 1.0×10^20 cm^-3 or higher, which is five or more times higher than the maximum nitrogen concentration in the silicon dioxide layer. By optimizing this specific parameter (nitrogen concentration), field-effect mobility is improved while maintaining a manageable manufacturing process through precise control of heat treatment conditions.
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 introduction of a nitrogen-rich transition region enhances the field-effect mobility and improves the electric characteristics of silicon carbide semiconductor devices by reducing defects at the interface, leading to better performance.
Implementation Method 1
A transition region with a high concentration of nitrogen, carbon, and oxygen is introduced between the silicon carbide and silicon dioxide layers, formed through a heat treatment process in an NO gas atmosphere, which increases nitrogen accumulation
Data Source
AI summary
The silicon carbide semiconductor device includes: a silicon carbide layer; a silicon dioxide layer provided above the silicon carbide layer and containing nitrogen; and a transition region arranged between the silicon carbide layer and the silicon dioxide layer, and containing carbon, oxygen, and nitrogen, wherein the maximum nitrogen concentration in the transition region is 1.0×1020 cm−3 or higher. The maximum nitrogen concentration in the transition region is five or more times higher than the maximum nitrogen concentration in the silicon dioxide layer.