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

摘要

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.