Growth and Microstructure of Epitaxial Ti<SUB>3</SUB>SiC<SUB>2</SUB> Contact Layers on SiC

Abstract

Growth and microstructure of ternary Ti 3 SiC 2 compound layers on 4H-SiC, which play am important role in formation of TiAl-based ohmic contacts to p-type SiC, were investigated in this study. The Ti 3 SiC 2 layer was fabricated by deposition of Ti/Al contacts (where a slash ''/'' indicates the deposition sequence) on the 4H-SiC(0001) substrate and subsequent rapid thermal anneal at 1000 C in ultra high vacuum. After annealing, reaction products and microstructure of the Ti 3 SiC 2 layer were investigated by X ray diffraction analysis and transmission electron microscopy observations in order to understand the growth processes of the Ti 3 SiC 2 layer and determination of the Ti 3 SiC 2 /4H-SiC interface structure. The Ti 3 SiC 2 layers with hexagonal plate shape were observed to grow epitaxially on the SiC(0001) surface by anisotropic lateral growth process. The interface was found to have a hetero-epitaxial orientation relationship of ð0001Þ TSC ==ð0001Þ S and ½0 1 110 TSC == ½0 1 110 S where TSC and S represent Ti 3 SiC 2 and 4H-SiC, respectively, and have well-defined ledge-terrace structures with low density of misfit dislocations due to an extremely low lattice mismatch of 0.4% between Ti 3 SiC 2 and 4H-SiC.

Step-flow growth of nanolaminate Ti3SiC2 epitaxial layers on 4H-SiC(0 0 0 1)

“…This agrees with the {000l} morphology with {11 2 0} step facets that we observe in XRD and in the SEM images of our samples, as well as observations by Tsukimoto et al [9], on Ti 3 SiC 2 layers formed by high-temperature annealing of TiAl-based ohmic contacts on 4H-SiC.…”

“…In such electronic device applications, a challenge is the formation of ohmic contacts to the SiC, as well as the durability of the contacts when operated at elevated temperatures. High-temperature annealed Ti/Al contacts on p-type SiC have been reported to form Ti 3 SiC 2 [5-8], which is suggested to contribute to the ohmic behavior of the contacts [9][10][11].Formation of Ti 3 SiC 2 and subsequent ohmic behavior has also been reported for hightemperature annealed Ti-based contacts on n-type SiC [12,13]. Here, we investigate the growth of Ti 3 SiC 2 thin films on 4° off-cut 4H-SiC using DC magnetron sputtering from three sources.…”

“…In such electronic device applications, a challenge is the formation of ohmic contacts to the SiC, as well as the durability of the contacts when operated at elevated temperatures. High-temperature annealed Ti/Al contacts on p-type SiC have been reported to form Ti 3 SiC 2 [5][6][7][8], which is suggested to contribute to the ohmic behavior of the contacts [9][10][11].…”

Growth and characterization of epitaxial Ti3GeC2 thin films on 4H-SiC(0001)

“…Ti 3 SiC 2 is known to form after high temperature annealing of Ti-, and Ti/Albased contacts on SiC [6][7][8][9][10]. In recent publications, we have reported on the ohmic contact properties of sputter-deposited Ti 3 SiC 2 on 4H-SiC(0001), and investigated the step-flow growth mode of epitaxially grown Ti 3 SiC 2 layers on SiC [11,12].…”

Phase Formation of Nanolaminated Transition Metal Carbide Thin Films

“…This topic is originated from the discovery of heteroepitaxial Ti3SiC2 formation at the interface of Ti/Al/4H-SiC and Ni/Ti/Al/4H-SiC after annealing at 1000 °C and 800 °C, respectively, which exhibited electrical Ohmic-contact behavior with low specific contact resistance [242]. Later, it has been reported that the Si-C-Si structure between the surface of SiC and the interfacial Ti3SiC2 has an important role of lowering Schottky barrier by intermediating the barrier height between the SiC substrate and the metal contact [243,244].…”