Characterization of p+-n Junctions and a Quasi-One-Dimensional Structure Fabricated by Low-Energy Focused Ion Beam

Abstract

The electrical properties of implanted p+ layers, shallow p+-n junctions, and a quasi-one-dimensional structure fabricated without masks by 20-keV Ga+ focused ion beam (FIB) on crystalline Si substrates were investigated in details. The distribution profile from SIMS showed discrepancies from LSS theory, which is considered to be the results of low beam energy and high beam current density. From Hall effect measurements, the Hall drift mobility was 131 cm2 / V-sec, which is 62% of the projected value due to remained defects after annealing. The I - V characteristics of p+-n junctions illustrated four distinct regions in the forward bias region and rising saturation current in the reverse bias region. Higher than expected leakage current is considered to be the results of residue damages after annealing. For the first time, the resistance of a quasi-one-dimensional structure was investigated. The resistance is 1 x 1 ,which is 647 times higher than the projected value. The cause of this phenomenon is considered to be the combined effects of interfacial roughness, the residue damages, and the shape of the structure.