Browsing by Subject "Charge trapping memories"

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    Silicon nanoparticle charge trapping memory cell
    (Wiley-VCH Verlag, 2014) El-Atab, N.; Ozcan, A.; Alkis, S.; Okyay, Ali Kemal; Nayfeh, A.
    A charge trapping memory with 2 nm silicon nanoparticles (Si NPs) is demonstrated. A zinc oxide (ZnO) active layer is deposited by atomic layer deposition (ALD), preceded by Al2O3 which acts as the gate, blocking and tunneling oxide. Spin coating technique is used to deposit Si NPs across the sample between Al2O3 steps. The Si nanoparticle memory exhibits a threshold voltage (Vt) shift of 2.9 V at a negative programming voltage of -10 V indicating that holes are emitted from channel to charge trapping layer. The negligible measured Vt shift without the nanoparticles and the good re- tention of charges (>10 years) with Si NPs confirm that the Si NPs act as deep energy states within the bandgap of the Al2O3 layer. In order to determine the mechanism for hole emission, we study the effect of the electric field across the tunnel oxide on the magnitude and trend of the Vt shift. The Vt shift is only achieved at electric fields above 1 MV/cm. This high field indicates that tunneling is the main mechanism. More specifically, phonon-assisted tunneling (PAT) dominates at electric fields between 1.2 MV/cm < E < 2.1 MV/cm, while Fowler-Nordheim tunneling leads at higher fields (E > 2.1 MV/cm). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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    Thin-film ZnO charge-trapping memory cell grown in a single ALD step
    (Institute of Electrical and Electronics Engineers, 2012-10-26) Oruc, F. B.; Cimen, F.; Rizk, A.; Ghaffari, M.; Nayfeh, A.; Okyay, Ali Kemal
    A thin-film ZnO-based single-transistor memory cell with a gate stack deposited in a single atomic layer deposition step is demonstrated. Thin-film ZnO is used as channel material and charge-trapping layer for the first time. The extracted mobility and subthreshold slope of the thin-film device are 23 cm2/V · s and 720 mV/dec, respectively. The memory effect is verified by a 2.35-V hysteresis in the $I\rm drain- $V\rm gate curve. Physics-based TCAD simulations show very good agreement with the experimental results providing insight to the charge-trapping physics.
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    ZnO based charge trapping memory with embedded nanoparticles
    (IEEE, 2012) Rizk, A.; Oruç, Feyza B.; Okyay, Ali Kemal; Nayfeh, A.
    A thin film ZnO charge trapping memory cell with embedded nanoparticles is demonstrated by Physics Based TCAD simulation. The results show 3V increase in the Vt shift due to the nanoparticles for the same operating voltage. In addition a 6V reduction in the programming voltage is obtained due the nanoparticles. In addition, the effect of the trapping layer and tunnel oxide scaling on the 10 year retention time is studied. © 2012 IEEE.