SiC Channel Capping Structure for Higher Carrier Mobility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional SiC-based devices face challenges with lower charge carrier mobility and material defects at the interface, which conventional doping and surface treatments fail to fully address.
Innovation Solution
A silicon carbide channel with opposite doping to the source and drain drift region, capped by a semiconductor with higher charge carrier mobility, and a gate structure on the capping semiconductor to enhance electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SiC substrate is used for high temperature and high voltage devices, then device reliability is improved, but charge carrier mobility is reduced
Solution Approach 1:
The patent uses a composite structure combining SiC substrate with a capping semiconductor layer (such as silicon or GeSi alloy) that has higher charge carrier mobility. This composite approach allows the device to benefit from both the high reliability of SiC and the high mobility of the capping material, resolving the contradiction between reliability and speed
2Quantity of substance
If conventional doping is applied to compensate for lower charge carrier mobility, then charge carrier concentration is increased, but material defects at interface increase
Solution Approach 1:
The capping semiconductor layer acts as an intermediary between the SiC substrate and the metal contact, providing a transition region that improves charge carrier mobility without requiring excessive doping. This mediator layer reduces the need for heavy doping and thereby minimizes interface defects
3Object-generated harmful factors
If surface treatments are applied to reduce defects, then interface quality is improved, but charge carrier mobility remains limited
Solution Approach 1:
The patent employs a composite structure where the capping semiconductor layer inherently provides both defect reduction and enhanced charge carrier mobility. The specific material composition and graded structure of the capping layer simultaneously address interface quality and mobility without relying solely on surface treatments
Data Source
AI summary
The disclosure provides a structure including a silicon carbide (SiC) channel horizontally between a source and a drain drift region. The SiC channel has opposite doping from the source and the drain drift region. A capping semiconductor is on the SiC channel and is horizontally between the source and the drain drift region. The capping semiconductor includes a semiconductor having a higher charge carrier mobility than the SiC channel. A gate structure is on the capping semiconductor.