Improved Ni ohmic contact on n-type 4H-SiC
1997 (English)In: Journal of Electronic Materials, ISSN 0361-5235, Vol. 26, no 3, 119-122 p.Article in journal (Refereed) Published
This paper presents the structural, chemical and electronic properties of Al/Ni/ Al-layers evaporated on 4H silicon carbide and then annealed at 1000°C for 5 min. The structure was investigated before and after annealing by transmission electron spectroscopy from cross-sectional specimens. With x-ray photoelectron spectroscopy, both element distribution and bonding energies were followed during sputtering through the alloyed metal-semiconductor contact. Voids are found in both annealed Ni/4H-SiC and Al/Ni/Al/4H-SiC contact layers, though closer to the metal-semiconductor interface in the former case. The first aluminum-layer is believed to prevent voids to be formed at the interface and also to reduce the oxide on the semiconductor surface. The contact was found to be ohmic with a specific contact resistance ρc - 1.8 × 10−5 Ωcm2 which is more than three times lower ρc than for the ordinary Ni/4H-SiC contact prepared in the same way.
Place, publisher, year, edition, pages
1997. Vol. 26, no 3, 119-122 p.
Al/Ni/Al/4H-SiC - transmission electron microscopy - x-ray photoelectron spectroscopy
IdentifiersURN: urn:nbn:se:liu:diva-62871DOI: 10.1007/s11664-997-0136-2OAI: oai:DiVA.org:liu-62871DiVA: diva2:374924