Laser direct-metallization of silicon carbide without metal deposition

Laser direct-write (LDW) is used for in-situ metallization in single crystal 4H- and 6H-SiC wafers without metal deposition. Nanosecond-pulsed Nd:YAG (lambda = 1064 and 532 nm) and excimer (lambda= 193, 248 and 351 nm) lasers are utilized to create metal-like conductive phases in both n-type and p-type SiC wafers. Frequency-doubled Nd:YAG irradiation( E-photon < E-g) induces a carbon rich conductive phase due to thermal decomposition of SiC. However, pulsed excimer laser irradiation (E-photon > E-g) produces a Si- rich conductive phases due to carbon photo ablation. The Schottky barrier heights (SBH) between the laser-metallized layer and the original n-type SiC (N-D = 10(18) cm(-3)) is determined to be 0.8 eV and 1.0 eV by the current-voltage and capacitance-voltage measurements at room temperature, respectively. Linear transmission line method pattern is directly fabricated in n-type doped (N-D = 10(18) cm(-3)) SiC substrate by pulsed laser irradiation allowing to extract the specific contact resistance (r(c)) of the laser fabricated metal-like tracks (r(c) = 0.04-0.12 Omegacm(2)).The specific contact resistance is unchanged after annealing up to 3 hrs at 950degreesC.