Dresden 2003 – scientific programme

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HL: Halbleiterphysik

HL 49: Poster II

HL 49.80: Poster

Thursday, March 27, 2003, 16:30–19:00, HSZ/P2

Charge Storage in Ion Beam Synthesized Au Nanocrystals Embedded in SiO₂ — •Torsten Müller, Volkhard Beyer, Johannes von Borany, and Karl-Heinz Heinig — Forschungszentrum Rossendorf, Institut für Ionenstrahlphysik und Materialforschung

Studies of semiconductor nanocrystals (NCs) in the MOS gate oxide received much interest due to their potential application in non-volatile memory devices. However, the detailed charge storage mechanism is still under discussion. Defect-based charge trapping at NC surfaces is hard to distinguish from storage in the conduction band of NCs. For metal NCs in SiO₂ the situation is different. Charge traps at the Au/SiO₂ interface are assumed to be negligible at first sight. In this contribution, Au NCs serve as a model system for the charge storage phenomena in NC containing gate oxides with a thickness of less than 40 nm. For the present study, Au NCs were synthesized by low-energy ion implantation followed by annealing. The formation of well-separated NCs (4..5 nm diameter) were observed by X-TEM studies. Additionally, a zone denuded of NCs forms at the interface. Thus, the formed NC-layer has the right distance from the Si/SiO₂ interface for charging by direct electron tunneling. On prepared MOS capacitor structures, charge storage behavior was successfully demonstrated by capacitance-voltage measurements.