Non-stoichiometric AlOxFilms Prepared by Chemical Vapor Deposition Using Dimethylaluminum Isopropoxide as Single Precursor and Their Non-volatile Memory Characteristics

Abstract

Dimethylaluminum isopropoxide (DMAI, <TEX>$(CH_3)_2AlO^iPr$</TEX>) as a single precursor, which contains one aluminum and one oxygen atom, has been adopted to deposit non-stoichiometric aluminum oxide (<TEX>$AlO_x$</TEX>) films by low pressure metal organic chemical vapor deposition without an additional oxygen source. The atomic concentration of Al and O in the deposited <TEX>$AlO_x$</TEX> film was measured to be Al:O = ~1:1.1 and any serious interfacial oxide layer between the film and Si substrate was not observed. Gaseous by-products monitored by quadruple mass spectrometry show that <TEX>${\beta}$</TEX>-hydrogen elimination mechanism is mainly contributed to the <TEX>$AlO_x$</TEX> CVD process of DMAI precursor. The current-voltage characteristics of the <TEX>$AlO_x$</TEX> film in Au/<TEX>$AlO_x$</TEX>/Ir metalinsulator-metal (MIM) capacitor structure show high ON/OFF ratio larger than <TEX>${\sim}10^6$</TEX> with SET and RESET voltages of 2.7 and 0.8 V, respectively. Impedance spectra indicate that the switching and memory phenomena are based on the bulk-based origins, presumably the formation and rupture of filaments.