Germanium Nanocrystals Embedded in Silicon Dioxide for Floating Gate Memory Devices

Authors A. Bag , R. Aluguri, S.K. Ray
Indian Institute of Technology Kharagpur, Department of Physics and Meteorology, IIT Kharagpur, 721302, Kharagpur, India
Issue Volume 3, Year 2011, Number 1, Part 5
Dates Received 04 February 2011, published online 08 December 2011
Citation A. Bag, R. Aluguri, S.K. Ray, J. Nano- Electron. Phys. 3 No1, 878 (2011)
PACS Number(s) 81.15.Cd, 81.07.Ta
Keywords Germanium nanocrystals (2) , Floating gate memory, Metal-oxide-semiconductor, Photoluminescence spectroscopy (2) , Flat band voltage.
Metal-oxide-semiconductor (MOS) capacitors with tri-layer structure consisting of rf magnetron sputtered grown germanium (Ge) nanocrystals (NCs) and silicon dioxide (SiO2) layers sandwiched between thermally grown tunnel and sputtered grown cap oxide layers of SiO2 were fabricated on p-Si substrates. Plane view transmission electron micrographs revealed the formation of spherically shaped and uniformly distributed Ge NCs. The optical and electronic characteristics of tri-layer structures were studied through photoluminescence (PL) spectroscopy and capacitance-voltage (C-V) measurements, respectively. Frequency dependent electrical properties of the structures have been studied. The optical emission characteristics support the confinement of the carriers in Ge NCs embedded in oxide matrices. An anticlockwise hysteresis in C-V characteristics suggests electron injection and trapping in Ge NCs.

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