Low resistive p-type GaN using two-step rapid thermal annealing processes

Two-step thermal annealing processes were investigated for electrical activ ation of magnesium- doped galliumnitride layers. The samples were studied b y room-temperature Hall measurements and photoluminescence spectroscopy at 16 K. After an annealing process consisting of a short-term step at 960 deg reesC followed by a 600 degreesC dwell step for 5 min a resistivity as low as 0.84 Ohm cm is achieved for the activated sample, which improves the res ults achieved by standard annealing (800 degreesC for 10 min) by 25% in res istivity and 100% in free hole concentration. Photoluminescence shows a pea k centered at 3.0 eV, which is typical for Mg-doped samples with high free hole concentrations. (C) 2001 American Institute of Physics.