EVALUATION OF DIFFERENT METALORGANIC PRECURSORS FOR Ge-Sb-Te THIN FILM DEPOSITION

ABSTRACT

In this work, various alkyl-precursors were tested, including: tetraethylgermanium (TEGe), tetraisopropylgermanium (TiPGe), triethyl-tert-butylgermanium (TEtBGe), trimethylantimony (TMSb), triisopropylantimony (TiPSb), dimethyltelluride (DMTe), diisopropyltelluride (DiPTe), and di-tert-butyltelluride (DtBTe), in order to deposit Ge-Sb-Te and Sb-Te thin films on Ni/SiO₂/Si, Ni/Ti/SiO₂/Si, Cu/SiO₂/Si, and Ir/Ti/SiO₂/Si substrates using pulsed metalorganic chemical vapor deposition. The deposition of Ge-Sb-Te films from methyl-group precursors is possible only at high temperatures (600–650°C). Using of TiPSb and DtBTe precursors significantly reduces the deposition temperature (≥300°C). By changing from DtBTe to DiPTe higher deposition temperatures were required (∼500°C) but the thermal stability of the Te-precursor was improved.

Keywords:

• GST
• MOCVD
• EDX
• DIPTe
• TIPSb
• TIPGe

ACKNOWLEDGMENTS

Financial support by the Deutsche Forschungsgemeinschaft (DFG) is grateful acknowledged. The authors would like to thank Dr. Garke and Dr. Bläsing of the Physics Department of the Otto-von-Guericke-University for carrying out XPS and XRD measurements, respectively, as well as to Swagelok Company for supplying specially designed ALD-valves.