Laser micromachining of circular transmission line model (CTLM) of Al contacts on n-type SiC/Si chips

An array of Circular Transmission Line Model (CTLM) metal contacts was deposited onto the upper surface of the n-SiC/Si chips using laser micromachining as an alternative to standard photolithography technique. Thin epitaxial n-type 3C-SiC/Si chips were used since no current leakage observed in previous studies. Various laser energies were used for the CTLM pattern transfer. Low values of ρc were obtained such 19x10-4 Ωcm2 was produced despite of different rings' diameters at the lower laser energy strength. However, high laser penetration had caused higher contact resistances approximately 20 times. This is probably attributed to the surface degradation of 3C-SiC.