Current transport and capacitance–voltage characteristics of GaAs and InP nanometer-sized Schottky contacts formed by in situ electrochemical process

Abstract

The nanometer-sized Schottky contacts were successively fabricated on n-GaAs and n-InP substrates by the electrochemical process, and their electrical properties were characterized both experimentally and theoretically. From the detailed I-V measurements using a conductive AFM system, it was found that the current transport properties of the nanometer-sized Schottky contacts were strongly dependent on metal workfunction, however showed nonlinear log I-V characteristics with large n value in range of 1.2 -2.0 which can not be explained by 1D thermionic emission model. From the theoretical analysis using a computer simulation, it was found that this nonlinear characteristics can be explained by the 3D thermionic emission model with a due consideration of the environmental Fermi level pinning. Furthermore, the calculated C-V characteristics showed much smaller movements of the depletion layer with bias underneath the nano-Schottky contacts. These results strongly indicate the importance of controlling the environmental Fermi level pinning to improve the potential controllability of the nano-Schottky contacts.

Disorder induced interface states and their influence on the Al/Ge nanowires Schottky devices

“…This behaviour was expected: interface states and the corresponding dipole charges were distributed in nearby surface layers inside the semiconductor, thus creating a charged and disordered electrical shell (few nanometers thick) around nanowires. 38,39 Fig . 3(c) shows the conduction band profile in z direction for different interface states densities at 300 K. The analysis of these results should be carefully accounted because U(z ¼ 0) values do not represent correctly the Schottky barrier height.…”

Electrochemical processes for formation, processing and gate control of III–V semiconductor nanostructures

“…We have been also studying electrical properties of such nano-Schottky diodes in detail by I-V and C-V measurements [56][57][58][59][60]. Figure 11(b) shows forward I-V curves of the Pt/, Ni/ and Sn/n-GaAs nano-Schottky contacts with a diameter of 90 nm.…”

Application of scanning probe microscopy to the characterization and fabrication of hybrid nanomaterials

“…DC c-AFM refers to contact mode electrical measurements taken with a time-independent bias. DC c-AFM has been applied to a wide range of materials including platinum nanowires (Macpherson et al, 2001), polypyrrole nanotubes (Park et al, , 2003, carbon nanotubes , quantum dots (Yamauchi et al, 1999), quantum point contacts (Topinka et al, 2000), compound semiconductors (Sato et al, 2001), and diamond films (L. Zhang et al, 2002). The remainder of our discussion focuses on hybrid inorganic and organic nanomaterials including organic semiconductors, immobilized biological systems, self-assembled monolayers, and organic-inorganic nanocomposites.…”