scholarly journals Anomalous Threshold Voltage Variability of Nitride Based Charge Storage Nonvolatile Memory Devices

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Meng Chuan Lee ◽  
Hin Yong Wong
Keyword(s):  
Threshold Voltage ◽  
Nonvolatile Memory ◽  
Charge Storage ◽  
Memory Devices ◽  
Nonvolatile Memory Devices ◽  
Anomalous Threshold

Future Silicon Nanocrystal Nonvolatile Memory Technology

2001 ◽  
Vol 686 ◽  
Author(s):  
Michele L. Ostraat ◽  
Jan W. De Blauwe
Keyword(s):  
Threshold Voltage ◽  
Flash Memory ◽  
Nonvolatile Memory ◽  
Gate Dielectric ◽  
Oxide Thickness ◽  
Channel Length ◽  
Charge Storage ◽  
Memory Devices ◽  
Two Stage ◽  
Nanocrystal Memory

AbstractA great deal of research interest is being invested in the fabrication and characterization of nanocrystal structures as charge storage memory devices. In these flash memory devices, it is possible to measure threshold voltage shifts due to charge storage of only a few electrons per nanocrystal at room temperature. Although a variety of methods exist to fabricate nanocrystals and to incorporate them into device layers, control over the critical nanocrystal dimensions, tunnel oxide thickness, and interparticle separation and isolation remains difficult to achieve. This control is vital to produce reliable and consistent devices over large wafer areas. To address these control issues, we have developed a novel two-stage ultra clean reactor in which the Si nanocrystals are generated as single crystal, nonagglomerated, spherical aerosol particles from silane decomposition at 950°C at concentrations exceeding 108 cm−3 at sizes below 10 nm. Using existing aerosol instrumentation, it is possible to control the particle size to approximately 10% on diameter. In the second reactor, particles are passivated with a high quality oxide layer with shell thickness controllable from 0.7 to 2.0 nm. The two-stage aerosol reactor is integrated to a 200 mm wafer deposition chamber such that controlled particle densities can be deposited thermophoretically. With nanocrystal deposits of 1013 cm−2, contamination of transition metals and other elements can be controlled to less than 1010 atoms cm−2.We have fabricated 0.2 μm channel length aerosol nanocrystal floating gate memory devices using conventional MOS ULSI processing on 200 mm wafers. The aerosol nanocrystal memory devices exhibit normal transistor characteristics with drive current 30 μA/μm, subthreshold slope 200 mV/dec, and drain induced barrier lowering 100 mV/V, typical values for thick gate dielectric high substrate doped nonvolatile memory devices. Uniform Fowler-Nordheim tunneling is used to program and erase these memory devices. Despite 5 nm tunnel oxides, threshold voltage shifts > 2 V have been achieved with microsecond program and millisecond erase times at moderate operating voltages. The aerosol devices also exhibit excellent endurance cyclability with no window closure observed after 105 cycles. Furthermore, reasonable disturb times and long nonvolatility are obtained, illustrating the inherent advantage of discrete nanocrystal charge storage. No drain disturb was detected even at drain biases of 4V, indicating that little or no charge conduction occurs in the nanocrystal layer. We have demonstrated promise for aerosol nanocrystal memory devices. However, numerous issues exist for the future of nanocrystal devices. These technology issues and challenges will be discussed as directions for future work.

Pentafluorosulfanylated polymers as electrets in nonvolatile organic field-effect transistor memory devices

2019 ◽  
Vol 7 (26) ◽  
pp. 7865-7871 ◽  
Author(s):  
Guoxian Zhang ◽  
Yu-Jung Lee ◽  
Prabhat Gautam ◽  
Chia-Chi Lin ◽  
Cheng-Liang Liu ◽  
...  
Keyword(s):  
Nonvolatile Memory ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Charge Storage ◽  
Memory Devices ◽  
Organic Field Effect Transistor ◽  
Nonvolatile Memory Devices ◽  
Effect Transistor ◽  
Styrenic Polymer ◽  
Polymer Electrets

Styrenic polymer electrets with pentafluorosulfanylated sidechains demonstrate their charge-storage capabilities in organic nonvolatile memory devices.

Metal nanocrystals as charge storage nodes for nonvolatile memory devices

2007 ◽  
Vol 52 (8) ◽  
pp. 2920-2926 ◽  
Author(s):  
P.H. Yeh ◽  
L.J. Chen ◽  
P.T. Liu ◽  
D.Y. Wang ◽  
T.C. Chang
Keyword(s):  
Nonvolatile Memory ◽  
Charge Storage ◽  
Memory Devices ◽  
Metal Nanocrystals ◽  
Nonvolatile Memory Devices

Fabrication of YMnO3 Films: New Candidate for Non-Volatile Memory Devices

1996 ◽  
Vol 433 ◽  
Author(s):  
Norifumi Fujimura ◽  
Tadashi Ishida ◽  
Takeshi Yoshimura ◽  
Taichiro Ito
Keyword(s):  
Nonvolatile Memory ◽  
Valence Electron ◽  
Bottom Electrode ◽  
Rf Magnetron Sputtering ◽  
Film Deposition ◽  
Deposition Condition ◽  
Memory Devices ◽  
Non Volatile Memory ◽  
Nonvolatile Memory Devices ◽  
First Time

AbstractWe have proposed ReMnO3 (Re:rare earth) thin films, as a new candidate for nonvolatile memory devices. In this paper, we try to fabricate (0001) oriented YMnO3 films on (111)MgO, (0001)ZnO:Al/(0001) sapphire and (111)Pt/(111)MgO using rf magnetron sputtering. We succeed in obtaining (0001) epitaxial YMnO3 films on (111) MgO and (0001)ZnO:Al/(0001)sapphire substrate, and polycrystalline films on (111)Pt/(1 11)MgO for the first time. Electrical property of the bottom electrode (ZnO:Al) changes with varying the deposition condition of YMnO3 films. However, we find an optimum deposition condition of ZnO:Al film such that it functions as a bottom electrode even after YMnO3 film deposition. The dielectric properties of the epitaxial and polycrystalline YMnO3 films are almost the same. The YMnO3 films show leaky electrical properties. This may be caused by a change in the valence electron of Mn from 3+.

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