TiN Schottky Contact for GaN Device Thermal Stability
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Solution Overview
Problem
Existing semiconductor devices with Schottky contacts, particularly those using nickel, face challenges in reproducibility, uniformity, thermal stability, and high-temperature operation, which are critical for high-power and high-voltage applications like GaN-based electronics.
Innovation Solution
The use of a TiN-based Schottky contact with a stack structure comprising TiW sub-layers and a TiW(N) sub-layer, deposited by Physical Vapour Deposition, provides a stable and effective Schottky barrier, with controlled nitrogen content to optimize electrical properties and prevent delamination, suitable for GaN-based devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nickel is used as the Schottky contact material, then the Schottky barrier can be formed, but the device shows poor reproducibility, uniformity, and thermal stability
Solution Approach 1:
The patent changes the material composition parameter from nickel to titanium nitride (TiN), which fundamentally alters the thermal stability and chemical reactivity characteristics. TiN maintains its compositional stability at high temperatures unlike nickel, directly resolving the thermal stability issue while maintaining Schottky barrier functionality.
Solution Approach 2:
The patent employs a composite multi-layer structure consisting of TiN, titanium tungsten nitride (TiW(N)), and aluminum layers. This composite approach combines materials with complementary properties: TiN provides thermal stability and Schottky barrier, TiW(N) provides adhesion and compositional control, and aluminum provides low-resistance connection, collectively improving reproducibility and uniformity.
2Reliability
If a simple Schottky contact structure is used, then the manufacturing process is simple, but the electrical performance and stability are insufficient
Solution Approach 1:
The Schottky contact is segmented into multiple functional layers: TiN layer for Schottky barrier formation, TiW(N) layer for adhesion and compositional control, and aluminum layer for low-resistance connection. This segmentation allows each layer to optimize its specific function, improving overall electrical performance while managing complexity through clear functional division.
Solution Approach 2:
Different layers are assigned different local qualities and compositions tailored to their specific functions. The TiN layer has high thermal stability for barrier formation, the TiW(N) layer has controlled nitrogen content for adhesion, and the aluminum layer has high conductivity for connection. This local optimization of material properties enhances electrical performance.
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 TiN-based Schottky contact enhances the stability and electrical performance of GaN-based semiconductor devices, ensuring reproducibility, uniformity, and high-temperature operation, making them suitable for high-power and high-frequency applications.
Implementation Method 1
The body of the Schottky contact may be deposited by Physical Vapour Deposition (PVD).
Data Source
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AI summary
A semiconductor device comprising at least one active layer on a substrate and a Schottky contact to the at least one active layer, the Schottky contact comprising a body of at least titanium and nitrogen that is electrically coupled with the at least one active layer.