Impact of Processing Parameters on Ti Schottky Contacts on 4H-SiC

Area of Science:

• Materials Science
• Semiconductor Physics
• Electrical Engineering

Background:

• Titanium (Ti) on 4H-Silicon Carbide (4H-SiC) forms Schottky contacts crucial for power devices.
• Understanding processing parameter effects on Ti/4H-SiC contact properties is vital for device optimization.

Purpose of the Study:

• To investigate the influence of deposition methods, annealing temperature, and Ti metal thickness on Ti/4H-SiC contact electrical characteristics.
• To elucidate current transport mechanisms and Schottky barrier properties for tailored device development.

Main Methods:

• Fabrication of Ti/4H-SiC contacts with varying Ti thicknesses (10-80 nm).
• Annealing treatments at temperatures ranging from 475 °C to 700 °C.
• Electrical characterization under forward and reverse biases to determine current transport mechanisms (thermionic emission and thermionic field emission).

Main Results:

• Annealing temperature reduction of Schottky barrier height from 1.19 to 1.00 eV for 80 nm Ti/4H-SiC.
• Current transport follows thermionic emission (TE) under forward bias and thermionic field emission (TFE) under reverse bias.
• Ti thickness reduction and interfacial reactions (Ti-Al region) decrease Schottky barrier height.

Conclusions:

• Processing parameters, particularly annealing temperature and Ti thickness, critically influence Ti/4H-SiC Schottky contact properties.
• The study provides insights into Schottky barrier height modulation and current transport mechanisms.
• Findings are valuable for designing Schottky barrier diodes with specific electrical characteristics.