Laser direct write doping of wide-bandgap semiconductor materials

Gas immersion laser doping (GILD) and molten precursor (predeposition and drive-in diffusion) laser doping are demonstrated in SiC. Trimethylaluminum (TMAI) and nitrogen are the precursors used to produce p-type and n-type SiC, respectively. Nd:YAG and excimer laser nitrogen doping in SiC epilayer and single crystal substrates increases the dopant concentration by two orders of magnitude and produces both deep (500-600 nm) and shallow (50 nm) junctions, respectively. Laser-assisted effusion/diffusion is introduced and utilized to dope Al in SiC wafers. Using this technique, a 150 nm p-type doped junction is fabricated in semi-insulating 6H-SiC and n-doped 4H-SiC wafers. This technique is used to p-type dope Mg in single crystal GaN to concentrations up to 10/sup 21/ cm/sup -3/ and 5/spl mu/m penetration., respectively, are achieved using various laser doping techniques. Laser direct write (LDW) conversion provides metallization to process Ohmic and rectifying contacts in these doped semiconductors, without the addition of metal, in order to conduct junction and device testing.