SiC Schottky Device with Stripe Gate and Separation Regions
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Solution Overview
Problem
Silicon carbide (SiC) devices experience rapid deterioration of electrical parameters, leading to a need for improved long-term stability, particularly in high-power applications where they are used as switches and rectifiers.
Innovation Solution
A silicon carbide device design incorporating a stripe-shaped gate structure with a Schottky contact and separation regions to enhance reliability and reduce bipolar degradation, while maintaining high channel density and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If silicon carbide devices are used for high-power applications, then power handling capability is improved, but electrical parameters deteriorate rapidly
Solution Approach 1:
The device is divided into multiple transistor cells arranged in series, with each cell having its own gate structure. This segmentation allows independent control and reduces the stress on individual cells, improving overall reliability while maintaining high power capability
Solution Approach 2:
A p-type separation region is introduced as an intermediary between the n-type cathode region and the n-type source region. This separation region acts as a mediator to reduce bipolar degradation and improve long-term stability of electrical parameters
2Productivity
If device thickness is reduced to match blocking voltage requirements, then manufacturing efficiency is improved, but electrical parameter stability deteriorates
Solution Approach 1:
Different regions of the device have different doping types and concentrations optimized for their specific functions. The p-type separation region provides local quality enhancement to prevent parameter deterioration in the thinner device structure
Solution Approach 2:
The device uses a composite structure with alternating n-type and p-type regions. This composite material approach allows the thin device to maintain electrical parameter stability by combining the benefits of different doping regions
3Productivity
If channel density is increased to improve efficiency, then power efficiency is improved, but device complexity increases
Solution Approach 1:
Multiple transistor cells are arranged in series to achieve high channel density and improved power efficiency. Each cell is a simple repeating unit, which manages complexity through modular design while providing high overall efficiency
Solution Approach 2:
Each transistor cell serves multiple functions: current conduction, voltage blocking, and contributes to overall device stability. This multi-functionality reduces the need for additional components, managing complexity while maintaining high efficiency
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 design improves long-term stability and short-circuit ruggedness, reduces leakage current, and maintains high channel density, effectively addressing the rapid parameter deterioration in SiC devices.
Implementation Method 1
The first load electrode and the cathode region form a Schottky contact
Implementation Method 2
The first load electrode and the source region form an ohmic contact
Data Source
AI summary
A silicon carbide device includes a silicon carbide body including a source region of a first conductivity type, a cathode region of the first conductivity type and separation regions of a second conductivity type. A stripe-shaped gate structure extends along a first direction and adjoins the source region and the separation regions. The silicon carbide device includes a first load electrode. Along the first direction, the cathode region is between two separation regions of the separation regions and at least one separation region of the separation regions is between the cathode region and the source region. The source region and the first load electrode form an ohmic contact. The first load electrode and the cathode region form a Schottky contact.