Memory window of highly c-axis oriented ferroelectric YMnO3 thin films

Abstract

YMnO3 thin films have been sputtered with different O-2 partial pressures from 0% to 20%. Only the YMnO3 sputtered without O-2 can be crystallized along (001) c-axis orientation after annealing at 870 degrees C. Mixing 10%-20% O-2 partial pressure in the sputtering ambient, the excess Y2O3 in the YMnO3 films suppresses the c-axis oriented crystallization. Effects of crystallization on the ferroelectric properties of Pt/YMnO3/Y2O3/Si (MEFIS) and Pt/YMnO3/Si (MFS) gate capacitors have been investigated. The memory window of the MEFIS capacitor is enhanced by the c-axis oriented crystallization of the YMnO3. (C) 1999 American Institute of Physics. [S0003-6951(99)01925-7].