-A A +A
We present a novel approach based on conductive atomic force microscope (c-AFM) for nano-scale mapping in laterally inhomogeneous metal–semiconductors Schottky contacts. For ultra-thin (1–5 nm) metal films with resistivity exceeding by about two orders of magnitude the bulk value, the current localization under the tip (10–20 nm diameter) occurs. By spectroscopic analysis of the current–voltage characteristics for different tip positions, the 2D Schottky barrier height (SBH) distribution is obtained with ∼0.1 eV energy resolution. The method was applied to explain the experimentally observed SBH lowering in macroscopic Au/4H–SiC diodes, in the presence of a not uniform SiO2 layer at the SiC/Au interface. Nano-scale mapping on the oxide free Au/4H–SiC contact demonstrates a SBH distribution peaked at 1.8 eV and with tails from 1.6 eV to 2.1 eV. When ∼2 nm not uniform SiO2 layer is intentionally grown …
Publication date: 
1 Mar 2007
Biblio References: 
Volume: 84 Issue: 3 Pages: 450-453
Microelectronic engineering