砷化錠鋁蕭基二極體的低溫製備及電性量測

Abstract

In this study, we prepared and characterized Au( or Pd)/n-AlGaAs Schottky diodes by using low-temperature(LT;T=77 K) process, current-voltage(I-V), and capacitance-voltage(C-V) measurements. The leakage current density is reduced half for the diodes fabricated by low-temperature process compared with which fabricated at room temperature(RT), corresponding to an increase of Schottky barrierheight to be around 40 meV. For an Au/Al0.28Ga0.72As sample, the saturationcurrent density is reduced from 6.4E-12 for RT preparation to 2.4E-12(A/cm2) forLT processing. The C-V measurements for RT diodes indicate that the barrier height is raised from 1.17eV for RT diodes to 1.20eV for LT diodes. In addition,we demonstrated that Se doping can be used to improved the quality of AlGaAs films by comparing the barrier heights and saturation current densities of RT and LT Schottky diodes made on Al0.3Ga0.7As epilayers.