THE CHARACTERISTIC DIODE PARAMETERS IN Ti/p-InP CONTACTS PREPARED BY DC SPUTTERING AND EVAPORATION PROCESSES OVER A WIDE MEASUREMENT TEMPERATURE

The titanium/p-indium phosphide (Ti/p-InP) Schottky diodes (SDs) have been prepared by thermal evaporation and DC magnetron sputtering deposition. Then, their current–voltage (I–V) characteristics have been measured in the sample temperature range of 100–400K with steps of 20K. The characteristic parameters of both Ti/p-InP SDs have been compared with each other. The barrier height (BH) values of 0.824 and 0.847 at 300K have been obtained for the sputtered and the evaporated SDs, respectively. This low BH value for the sputtered SD has been attributed to some defects introduced by the sputtered deposition technique over a limited depth in to the p-type substrate. The BH of the evaporated and sputtered diodes has decreased with the standard deviations of 58 and 64mV obeying to double-Gaussian distribution (GD) in 220–400K range, respectively, and it has seen a more sharper reduction for the BHs with the standard deviations of 93 and 106 mV in 100–220K range. The Richardson constant values of 89.72 and 53.24A(Kcm)−2 (in 220–400K range) for the evaporated and sputtered samples, respectively, were calculated from the modified ln(I0/T2)−q2σs2/2k2T2 vs (kT)−1 curves by GD of the BHs. The value 53.24A(Kcm)−2 for the sputtered sample in high temperatures range is almost the same as the known Richardson constant value of 60A(Kcm)−2 for p-type InP.