Schottky Contact Stack with Phonon Scattering Layer for Thermal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The fabrication of semiconductor devices with non-ohmic contacts, such as Schottky contacts, is challenged by high temperatures during the manufacturing process, which can degrade the performance of the contacts in blocking leakage current.
Innovation Solution
Incorporating a phonon scattering layer, specifically ruthenium (Ru) with a work function of 4.5 eV to 5.7 eV and a melting point of 1550°C to 3200°C, which functions as both a Schottky junction and a phonon scattering layer, reducing heat susceptibility and the need for additional diffusion barrier layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional metal layers (Ni, Au) are used to form Schottky contacts on AlGaN semiconductor body, then the contact structure is simple and easy to manufacture, but the high temperature during fabrication degrades the performance of the contacts in blocking leakage current
Solution Approach 1:
A phonon scattering layer is introduced as an intermediary between the semiconductor body and the metal contact layers. This intermediate layer acts as a thermal barrier that scatters phonons (heat carriers), reducing heat susceptibility and protecting the Schottky junction from thermal degradation during fabrication processes, thereby maintaining leakage current blocking performance at high temperatures
Solution Approach 2:
The contact structure is designed as a composite multi-layer system comprising a phonon scattering layer (made of materials like W, Mo, Pt, Pd, Rh, Ru, or Ir with high melting points and appropriate work functions) combined with traditional metal contact layers. This composite structure integrates both thermal management functionality and electrical contact functionality, achieving improved thermal stability while maintaining reliable electrical performance
2Reliability
If additional diffusion barrier layers are added to protect against thermal degradation, then the thermal stability is improved, but the device complexity and manufacturing process become more complex
Solution Approach 1:
The phonon scattering layer is designed to perform multiple functions simultaneously: it serves as a thermal barrier to protect the Schottky junction from thermal degradation, acts as a diffusion barrier to prevent metal atom interdiffusion into the semiconductor, and maintains appropriate electrical properties for forming a functional Schottky contact. This multi-functionality eliminates the need for separate diffusion barrier layers, reducing structural complexity while maintaining thermal stability
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 solution effectively reduces reverse leakage current and enhances the thermal stability and mechanical robustness of the Schottky contacts, improving the overall performance and reliability of semiconductor devices.
Implementation Method 1
Incorporating a phonon scattering layer, specifically ruthenium (Ru) with a work function of 4.5 eV to 5.7 eV and a melting point of 1550°C to 3200°C, which functions as both a Schottky junction and a phonon scattering layer, reducing heat susceptibility
Data Source
AI summary
A transistor device includes a semiconductor body and a non-ohmic contact on the semiconductor body. The non-ohmic contact includes a phonon scattering layer on the semiconductor body, a protection layer on a surface of the phonon scattering layer opposite the semiconductor body, and a contact layer on a surface of the protection layer opposite the phonon scattering layer. The phonon scattering layer has a work function in a range of about 4.5 eV to about 5.7 eV and a melting point in a range of about 1550° C. to about 3200° C.