[21p-PB6-1~10] 15.6 Group IV Compound Semiconductors (SiC)

▲ [21p-PB6-8] Low Specific Contact Resistance TiNb Ohmic Contacts to 4H-SiC with Laser Annealing for Harsh Environment Applications

〇(D)Cuong Van Vuong¹, Teruhisa Kawasaki², Shin-Ichiro Kuroki¹ (1.Hiroshima Univ. RNBS, 2.Sumitomo Heavy Industries Ltd.)

Keywords:SiC, Ohmic contacts, Laser annealing

Low specific contact resistivity of Ti(75 nm)Nb(x nm) (where x = 15, 25, 50 nm) contacts to C-face of n-type 4H-SiC with laser annealing was investigated. After the annealing process, the linear dependence of the current on the applied voltage indicated that all the samples exhibited ohmic behavior when the laser energy density varied from 1.9 to 2.8 J/cm² at the laser wavelength of 355 nm. Based on Transfer Length Measurement (TLM) method, the lowest specific contact resistivity was 1.56 x 10^-4 Ωcm² in the case of Ti(75)Nb(15) at the laser energy density of 1.9 J/cm². The dependence of the specific contact resistivity on the laser energy density showed that Ti(75)Nb(25) sample has low specific contact resistivity maintained at a small value when changing the laser power. This results indicated that with the appropriate thickness of Nb, not only the excess carbon atoms were collected by the formation of Nb_xC_y but also low specific contact resistivity was ensured. This also means that Ti(75)Nb(25) can be a potential candidate to operate stably in high temperature as well as high power environments.