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

Dimethylaluminum isopropoxide (DMAI, (CH₃)₂AlOⁱPr ) as a single precursor, which contains one aluminum and one oxygen atom, has been adopted to deposit non-stoichiometric aluminum oxide ( AlOₓ ) films by low pressure metal organic chemical vapor deposition without an additional oxygen source. The atomic concentration of Al and O in the deposited AlOₓ 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 β -hydrogen elimination mechanism is mainly contributed to the AlOₓ CVD process of DMAI precursor. The current-voltage characteristics of the AlOₓ film in Au/ AlOₓ /Ir metalinsulator-metal (MIM) capacitor structure show high ON/OFF ratio larger than ~10⁶ 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.