SiC Schottky Diode Barrier Height Reduction
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Solution Overview
Problem
Schottky barrier diodes using SiC face challenges in achieving a low and stable forward voltage due to high barrier heights between the metal anode and SiC, leading to increased voltage drop and instability.
Innovation Solution
A semiconductor device structure incorporating a conductive layer with titanium, oxygen, and at least one element from vanadium, niobium, or tantalum, which forms a metal oxide with adjustable work function, reducing the barrier height and enabling low forward voltage operation while maintaining stability through controlled impurity concentrations and crystal structure optimization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a metal anode is directly contacted with SiC to form a Schottky barrier diode, then the device structure is simple, but the barrier height is high causing high forward voltage and instability
Solution Approach 1:
A conductive layer comprising titanium (Ti), oxygen (O), and at least one element from vanadium (V), niobium (Nb), and tantalum (Ta) is introduced between the metal anode and the SiC drift region. This intermediary layer reduces the barrier height at the metal-SiC interface, enabling low forward voltage operation while maintaining stability without requiring complex multi-layer structures or high-temperature heat treatments.
2Stability of the object's composition
If high-temperature heat treatment is applied to the Schottky barrier diode, then the crystal structure can be optimized, but the barrier height becomes unstable due to material diffusion and phase changes
Solution Approach 1:
The conductive layer is designed with specific compositional parameters (Ti, O, and at least one of V, Nb, Ta) that enable the formation of a stable low-barrier interface without requiring high-temperature heat treatment. The oxygen content and metal ratios are controlled to achieve the desired electrical characteristics while avoiding barrier height instability caused by thermal processing.
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 proposed structure achieves a low and stable forward voltage in SiC Schottky barrier diodes, enabling high-frequency operation and stable switching characteristics without the need for high-temperature heat treatments, which can cause barrier height variations.
Implementation Method 1
a conductive layer provided between the first SiC region and the first metal layer, the conductive layer including titanium (Ti), oxygen (O), and at least one element from vanadium (V), niobium (Nb), and tantalum (Ta)
Data Source
AI summary
A semiconductor device according to an embodiment includes a first metal layer, a second metal layer, an n-type first SiC region provided between the first metal layer and the second metal layer and having an n-type impurity concentration of 1×1018 cm−3 or less, and a conductive layer provided between the first SiC region and the first metal layer and containing titanium (Ti), oxygen (O), and at least one element selected from the group consisting of vanadium (V), niobium (Nb), and tantalum (Ta).