Low specific contact resistance on epitaxial p-type 4H-SiC with a step-bunching surface
This paper reports the performances of Ti/Al based ohmic contacts fabricated on highly doped p-type 4H-SiC epitaxial layer which has a severe step-bunching surface. Different contact schemes are investigated based on the AI:Ti composition with no more than 50 at.% Al. The specific contact resistance...
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Published in | Chinese physics B Vol. 24; no. 11; pp. 452 - 459 |
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Main Author | |
Format | Journal Article |
Language | English |
Published |
01.11.2015
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Subjects | |
Online Access | Get full text |
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Summary: | This paper reports the performances of Ti/Al based ohmic contacts fabricated on highly doped p-type 4H-SiC epitaxial layer which has a severe step-bunching surface. Different contact schemes are investigated based on the AI:Ti composition with no more than 50 at.% Al. The specific contact resistance (SCR) is obtained to be as low as 2.6 × 10-6Ωcm2 for the bilayered Ti(100 nm)/Al(100 nm) contact treated with 3 rain rapid thermal annealing (RTA) at 1000 ℃. The microstructure analyses examined by physical and chemical characterization techniques reveal an alloy-assisted ohmic contact formation mechanism, i.e., a high degree of alloying plays a decisive role in forming the interfacial ternary Ti3SiC2 dominating the ohmic behavior of the Ti/Al based contact. Furthermore, a globally covered Ti3 SiC2 layer with (0001)-oriented texture can be formed, regardless of the surface step bunching as well as its structural evolution during the metallization annealing. |
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Bibliography: | This paper reports the performances of Ti/Al based ohmic contacts fabricated on highly doped p-type 4H-SiC epitaxial layer which has a severe step-bunching surface. Different contact schemes are investigated based on the AI:Ti composition with no more than 50 at.% Al. The specific contact resistance (SCR) is obtained to be as low as 2.6 × 10-6Ωcm2 for the bilayered Ti(100 nm)/Al(100 nm) contact treated with 3 rain rapid thermal annealing (RTA) at 1000 ℃. The microstructure analyses examined by physical and chemical characterization techniques reveal an alloy-assisted ohmic contact formation mechanism, i.e., a high degree of alloying plays a decisive role in forming the interfacial ternary Ti3SiC2 dominating the ohmic behavior of the Ti/Al based contact. Furthermore, a globally covered Ti3 SiC2 layer with (0001)-oriented texture can be formed, regardless of the surface step bunching as well as its structural evolution during the metallization annealing. 11-5639/O4 4H-SiC, p-type, ohmic contact, alloying, step bunching ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1674-1056 2058-3834 1741-4199 |
DOI: | 10.1088/1674-1056/24/11/117304 |