Crystallization and Improvement of Electrical Properties of Bi5Nb3O15 Thin Films Crown at Low Temperature

Abstract

Amorphous Bi(5)Nb(3)iO(15) (B5N3) phase was formed for the films grown at 350 degrees C under low oxygen pressures (OPs) (<= 200 m Torr). However, when OP exceeded 400 mTorr. crystalline Bi3NbO7 (B3N) phase, which is a low temperature transient phase of the crystalline B5N3 phase. was formed even at 350 degrees C The dielectric constant (k) increased with increasing OP due to the formation of the crystalline B3N phase The leakage current density increased with increasing OP, due to the increased surface roughness of the film Presence of the intrinsic oxygen vacancies was also responsible for the increased leakage current density. Mn-doping improved the electrical properties of the films by producing the doubly ionized, extrinsic oxygen vacancies which reduced the number of the intrinsic oxygen vacancies Mn-doping also considerably increased the k value of the film to a maximum of 108 for the 5 0 mol% Mn-doped film grown at 350 degrees C (C) 2009 The Japan Society of Applied Physics