Characteristics of silicon nanocrystal floating gate memory using amorphous carbon/SiO2 tunnel barrier

Abstract

Nanocrystal floating gate memory employing an amorphous carbon (a-C)/SiO2 double-layered tunnel barrier was fabricated. The band gap of a-C and conduction band discontinuity between a-C and Si was estimated to be 1.95 and 0.4 eV, respectively. In addition, interface states density of the a-C/SiO2/channel Si was estimated from the capacitance-voltage measurement. The nanocrystal memory using this tunnel barrier exhibited enhanced charge retention than that employing a single SiO2 tunnel barrier whereas the injection efficiency is comparable between them, which is due to the asymmetrical band profile of the tunnel barrier. (C) 2002 American Institute of Physics. [DOI: 10.1063/1.1533119].