Ni/Ti ohmic and Schottky contacts on 4H-SiC formed with a single thermal treatment
2004; Elsevier BV; Volume: 14; Issue: 3-7 Linguagem: Inglês
10.1016/j.diamond.2004.11.015
ISSN1879-0062
AutoresR. Pérez, N. Mestres, Dominique Tournier, Philippe Godignon, José del R. Millán,
Tópico(s)Thin-Film Transistor Technologies
ResumoThe behaviour of Ni/Ti bilayer contacts on 4H-SiC with different thermal anneals is reported, as well as their impact on the electrical characteristics of both Schottky and PN diodes processed on the same wafer. A 350 °C rapid thermal annealing (RTA) provides the optimal forward performances of Schottky contacts with the lowest forward voltage drop (1.1 V at 100 A/cm2). The ohmic contact improves by increasing the RTA temperature, as inferred from the contact resistivity (ρC) decrease detected from rectangular TLM test structures. For higher RTA temperatures (700–900 °C), the contact shows good ohmic characteristics on PN diodes and not severely degraded rectifying properties on Schottky diodes. Concerning reverse measurements, a significant improvement in the breakdown voltage of Schottky diodes has been observed with a 900 °C contact annealing, due to the high Schottky barrier formed with this high temperature treatment.
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