N. Lundberg et al., TEMPERATURE STABILITY OF COBALT SCHOTTKY CONTACTS ON N-TYPE AND P-TYPE 6H SILICON-CARBIDE, Applied surface science, 73, 1993, pp. 316-321
Rectifying Schottky contacts have been manufactured on n- and p-type 6
H silicon carbide using e-beam evaporation of cobalt. Heat treatments
in the 300 to 1100 degrees C temperature range have been made to study
the feasibility of high temperature contacts in this material system.
Rutherford backscattering spectrometry and X-ray diffraction have rev
ealed the formation of different cobalt silicides (Co2Si, CoSi, and Co
Si2) at higher temperatures than for the Co/Si system. No evidence of
silicidation was found below 600 degrees C and SEM micrographs reveale
d carbon agglomerates at the surface after silicidation. Electrical pr
operties have been examined using I-V and C-V measurements, and the ba
rrier heights of cobalt and Co2Si were evaluated. The contacts display
ed excellent forward I-V characteristics with good linearity over 3-6
decades and were rectifying even after heat treatments al 800 degrees
C.