PDAL SCHOTTKY CONTACT TO IN0.52AL0.48AS GROWN BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION

beta-PdA1 was studied as a Schottky contact to metalorganic chemical vapor deposition grown In0.52Al0.48As Intermetallic alloy beta-PdAl was chosen in order to utilize the Al-In exchange reaction which may occur between PdAl and In0.52Al0.48As, which would result in an enhanced Schottky barrier height. I-V, C-V, and deep level transient spectroscopy (DLTS) were used to determine the contact characteristics. The contact barrier height (phi(b)) was measured by I-V and C-V methods after different annealing conditions, and good agreement between I-V and C-V results were obtained. The largest phi(b) value is 0.67 eV from I-V measurement (0.69 eV from C-V) after the diode was annealed at 450 degrees C for 1 min. DLTS measurements were carried out to examine the effect of deep traps in the In0.52Al0.48As layer. Two deep levels were found, but the concentrations are lower than the intrinsic donor concentration obtained from the Hall method. The activation energies for these two deep levels obtained from an Arrhenius plot are 0.38 and 0.65 eV, respectively. (C) 1995 American Institute of Physics