Ohmic Contacts on p-Type SiC Using Al/C Films
| Autor: | G. R. Landis, William C. Mitchel, Wei Jie Lu, W. E. Collins |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Diffraction
Materials science Annealing (metallurgy) Mechanical Engineering Single component Metallurgy Alloy engineering.material Condensed Matter Physics Chemical instability Metal Mechanics of Materials visual_art visual_art.visual_art_medium engineering General Materials Science Composite material Ohmic contact Stoichiometry |
| Zdroj: | Materials Science Forum. :899-902 |
| ISSN: | 1662-9752 |
| DOI: | 10.4028/www.scientific.net/msf.527-529.899 |
| Popis: | Al based alloys, such as Ti/Al, are commonly used for ohmic contacts on p-type SiC. The interfacial structures of a metal alloy film on SiC are very complicated after annealing. Al is considered as the key element responsible for forming ohmic contacts on p-type SiC, and reacts with C from SiC and forms Al4C3 and Si during annealing. In this study, we have investigated ohmic contact formation of a single component Al4C3 film on p-type SiC. Based on the stoichiometric formation of Al4C3 between Al and C at high temperatures, several samples with various Al/C mole ratios have been examined for ohmic contact formation after different annealing temperatures. Carbon rich and stoichiometric Al4C3 films form ohmic contacts on p-type 4H-SiC (~2.8 x1018 cm-3 ) after annealing at 800 and 900°C. X-ray diffraction (XRD) data have shown that a single component Al4C3 is formed when an ohmic contact on p-type SiC is activated. Al/SiC, as the control sample, does not form ohmic contacts under the same conditions. This study reveals that Al4C3 can be responsible for forming ohmic contacts on p-type SiC. However, its chemical instability requires that the secondary metal is necessary to form stable ohmic contacts when Albased films are used. |
| Databáze: | OpenAIRE |
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