Charge Storage and Optical Response of Hybrid Nanodots Floating Gate For Functional Memories

Abstract

We have proposed and fabricated a hybrid nanodots floating gate (FG), in which Si quantum dots (QDs) as charge injection/emission nodes and NiSi nanodots as charge storage nodes are stacked with an ultrathin SiO 2 interlayer, to satisfy both large memory window and multivalued capability. In this study, Si-QDs with an areal density of ~3x10 11 cm -2 were formed on ultrathin SiO 2 layer by controlling SiH 4 chemical vapor deposition (CVD) and NiSi nanodots were prepared by full-silicidation of Si-QDs promoted with remote H 2 -plasma exposure after Ni evaporation. From capacitance-voltage(C-V) characteristics of MOS capacitors with a NiSi nanodots/Si-QDs hybrid FG, stable storage of many charges in the deep potential well of each NiSi nanodot was confirmed. Also, by applying pulsed gate biases, stepwise charge injection to and emission from NiSi nanodots through discrete energy states in Si-QDs were demonstrated. In addition, by 1310nm (~0.95eV) light irradiation, a distinct optical response in C-V characteristics was detected, which can be interpreted in terms of the shift of charge centroid in the hybrid FG stack due to transfer of photoexcited electrons from NiSi-nanodots to the Si-QDs.

A DFT Study of Ruthenium fcc Nano-Dots: Size-Dependent Induced Magnetic Moments

“…Nano-dots are localised nanometre-scale structures, whereas quantum dots are nanoparticles made from semiconductor materials, all exhibiting localised magnetic or electrical fields at very small scales. These localised properties can be exploited, particularly for use in light-emitting devices [ 1 , 2 , 3 ], information storage [ 4 , 5 , 6 ] and energy storage [ 7 , 8 , 9 ]. Nano-dots can be thought of as small magnets which can switch polarity and this change is exploited exclusively in new hard drives [ 10 ], solar cells [ 11 , 12 ], super capacitors [ 13 ] and batteries [ 14 , 15 , 16 ].…”