1,721,114 research outputs found
Experimental study of data retention in nitride memories by temperature and field acceleration
No full textRTN VT instability from the stationary trap-filling condition: an analytical spectroscopic investigation
No full textComprehensive analysis of random telegraph noise instability and its scaling in deca-nanometer Flash memories
No full textThis paper presents a comprehensive investigation of
random telegraph noise (RTN) in deca–nanometer Flash memories, considering both the NOR and the NAND architecture. The statistical distribution of the threshold voltage instability is analyzed in detail, evidencing that the slope of its exponential tails is the critical parameter determining the scaling trend for RTN. By means of 3-D TCAD simulations, the slope is shown to be the result of cell geometry, atomistic substrate doping, and random placement of traps over the cell active area. Finally, the slope dependence on cell geometry (width, length, and oxide thickness), doping, and bias conditions is summarized in a powerful formula that is able to predict the RTN instabilities in deca–nanometer Flash memorie
Analytical model for the electron-injection statistics during programming of nanoscale NAND Flash memories
No full textWe present a detailed analytical modeling for the constant-current Fowler–Nordheim program operation of NAND Flash memories, able to describe both the average transient of the cell threshold voltage and its statistical spread due to the granular nature of the electron current flowing through the cell tunnel oxide. We analytically investigate the electron-injection process, highlighting that the steepness of the tunneling current versus floating-gate voltage characteristics and the control-gate to
floating-gate capacitance give the field feedback factor, determining the average number of injected electrons at which the injection process becomes sub-Poissonian. Finally, we show that cell scaling will reduce the achievable accuracy of the program algorithm, due to the reduction in the number of electrons controlling cell state
Threshold-voltage statistics and conduction regimes in nanocrystal memories
No full textResults of three-dimensional Monte Carlo simulations
of nanocrystal (NC) memory cells are presented to investigate
the statistical properties of the threshold-voltage shift (ΔVT ). It
is shown that NC-number fluctuations dominate the ΔVT spread
in the ON-state cell conduction regime, while percolation effects
add a significant contribution to the statistical spread in the subthreshold
region. The dependence of theΔVT statistics on the cell
geometry is also investigated, which shows that NC number and
position fluctuations can strongly affect the memory performance
and must be suitably modeled
Time Dependent Threshold-Voltage Fluctuations in NAND Flash Memories: From Basic Physics to Impact on Array Operation
No full textDoping engineering for random telegraph noise suppression in deca-nanometer Flash memories
No full textDegradation dynamics for deep scaled p-MOSFET's during hot-carrier stress
No full textHot-Carrier degradation in p-channel MOSFET's is investigated comparing Hydrogen (H2) and Deuterium (D2) annealed devices. Two physical mechanisms are clearly recognized during low gate voltage stress (|VG| |VDS|), namely the Hot-Electron-Induced Punch-through (HE1P) and the Interface State Generation (ISG). The dependence of the degradation dynamics on the gate oxide thickness is discussed in detail, showing that the Deuterium giant isotope effect can improve the lifetime of deep sub-micron pMOSFET's by reducing the ISG process. Finally, the accelerated stress protocol commonly used to evaluate pMOSFET Hot-Carrier reliability is critically reviewed
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