Experimental study of single-electron phenomena in silicon nanocrystal memories.
In this paper we present experimental evidence for single-electron phenomena in solid-state memories based on silicon nanocrystals as storage elements. The stepwise evolution of the channel current of a written memory cell biased in the subthreshold regime is monitored by means of a purposely designed low noise acquisition system with a bandwidth of 1 kHz. Each channel current step-up is ascribed to a single-electron emission from the silicon nanocrystal to the silicon substrate and each current step-down is ascribed to a single-electron capture from the silicon substrate into the silicon nanocrystal. The effect of the measurement system bandwidth on the detection of single-electron events is discussed and a procedure for extracting the threshold voltage shift associated to these events is proposed. It is shown that single-electron charging and discharging events in a memory cell with an area of 4.5 x 10(-10) cm2 can cause threshold voltage shift at room-temperature of the order of several millivolts. Qualitative explanation for the observed threshold voltage shift distribution is given.
Pace
C
C
DEIS, University of Calabria, Via P. Bucci 41C, I-87036, Arcavacata di Rende (CS), Italy.
Crupi
F
F
Corso
D
D
Lombardo
S
S
D016248:Computer Storage Devices; D004563:Electrochemistry / Q000379:methods; D004583:Electrons; D016247:Information Storage and Retrieval; D007477:Ions; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D012825:Silicon / Q000737:chemistry*; D012984:Software; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
D007477:Ions; D012825:Silicon