Pt:Ti Diffusion Barrier, Interconnect, and Simultaneous Ohmic Contacts to n- and p-Type 4H-SiC


Article Preview

We report the initial results of using co-sputtered Pt:Ti 80:20 at. % composition ratio metallization as a diffusion barrier against gold (Au) and oxygen (O), as an interconnect layer, as well as forming simultaneous ohmic contacts to n-and p-type 4H-SiC. Having a single conductor with such combined multi-functional attributes would appreciably reduce the fabrication costs, processing time and complexity that are inherent in the production of SiC based devices. Auger Electron Spectroscopy, Focused Ion Beam-assisted Field Emission Scanning Electron Microscopy and Energy Dispersive Spectroscopy analyses revealed no Au and O migration to the SiC contact surface and minimal diffusion through the Pt:Ti barrier layer after 15 minutes of exposure at 800 oC in atmosphere, thus offering potential long term stability of the ohmic contacts. Specific contact resistance values of 7 x 10-5 and 7.4 x 10-4 Ω-cm2 were obtained on the n (Nd=7 x 1018 cm-3) and p (Na=2 x 1020 cm-3) -type 4H-SiC, respectively. The resistivity of 75 μΩ-cm was obtained for the Pt:Ti layer that was sandwiched between two SiO2 layers and annealed in pure O ambient up to 900 °C, which offers promise as a high temperature interconnect metallization.



Edited by:

Robert Stahlbush, Philip Neudeck, Anup Bhalla, Robert P. Devaty, Michael Dudley and Aivars Lelis




R. S. Okojie and D. Lukco, "Pt:Ti Diffusion Barrier, Interconnect, and Simultaneous Ohmic Contacts to n- and p-Type 4H-SiC", Materials Science Forum, Vol. 924, pp. 381-384, 2018

Online since:

June 2018




* - Corresponding Author

[1] R. Okojie and D. Lukco, Simultaneous ohmic contacts to p- and n-type 4H-SiC by phase segregation annealing of co-sputtered Pt-Ti, J. Appl. Phys. 120, (2016) 215301.

[2] S.P. Murarka, H.J. Levinstein, I. Blech, T.T. Sheng, and M.H. Read, Investigation of the Ti‐Pt diffusion barrier for gold beam leads on aluminum, J. Electrochem. Soc. 125(1), (1978) 156.

[3] Information on

[4] L. J. Brillson, M. L. Slade, H. W. Richter, H. VanderPlas, and R. T. Fulks, Titanium–silicon and silicon dioxide reactions controlled by low temperature rapid thermal annealing, J. of Vac. Sci. & Tech. A: Vacuum, Surfaces, and Films 4, (1986) 993.

[5] CRC Handbook of Chemistry and Physics, 64th ed. (1984).

Fetching data from Crossref.
This may take some time to load.