Charge-trapping memory cell of SiO2∕SiN∕high‐k dielectric Al2O3 with TaN metal gate for suppressing backward-tunneling effect

2005 ◽  
Vol 87 (7) ◽  
pp. 073510 ◽  
Author(s):  
Chang-Hyun Lee ◽  
Kyu-Charn Park ◽  
Kinam Kim
2006 ◽  
Vol 933 ◽  
Author(s):  
Chang-Hyun Lee ◽  
Changseok Kang ◽  
Yoocheol Shin ◽  
Jaesung Sim ◽  
Jongsun Sel ◽  
...  

ABSTRACTWe present the TANOS (Si-Oxide-SiN-Al2O3-TaN) cell with 40 Å-thick tunnel oxide erased by Fowler-Nordheim (FN) tunneling of hole. Thanks to introducing high-k dielectrics, alumina (Al2O3) as a blocking oxide, the erase threshold voltage can be maintained to less than - 3.0 V, meaning hole-trapping in SiN. We extracted the nitride trap densities of electron and hole for the TANOS cell. It is demonstrated that the TANOS structure is very available to investigate the trap density with shallower energy. The energy level of hole trap (1.28 eV) is found to be deeper than that of electron (0.8 eV). As the cycling stress is performed, persistent hole-trapping is observed unlike endurance characteristics of conventional floating-gate cell. The hole trapping during the cycling stress can be attributed to two possibilities. The injected holes are trapped in neutral trap of tunnel oxide and residue of holes which is not somewhat compensated by injected electrons may be accumulated in SiN. It is demonstrated the erase operation of the TANOS cell is governed by Fowler-Nordheim tunneling of hole due to the field concentration across the tunnel oxide.


2019 ◽  
Author(s):  
Z.-H. Fan ◽  
M. Zhang ◽  
L. Chen ◽  
Q.-Q. Sun ◽  
D.W. Zhang

2020 ◽  
Vol 29 (01n04) ◽  
pp. 2040001
Author(s):  
N. R. Butterfield ◽  
R. Mays ◽  
B. Khan ◽  
R. Gudlavalleti ◽  
F. C. Jain

This paper presents the theory, fabrication and experimental testing results for a multiple state Non-Volatile Memory (NVM), comprised of hafnium oxide high-k dielectric tunnel and gate barriers as well as a Silicon Quantum Dot Superlattice (QDSL) implemented for the floating gate and inversion channel (QDG) and (QDC) respectively. With the conclusion of Moore’s Law for conventional transistor fabrication, regarding the minimum gate size, current efforts in memory cell research and development are focused on bridging the gap between the conventions of the past sixty years and the future of computing. One method of continuing the increasing chip density is to create multistate devices capable of storing and processing additional logic states beyond 1 and 0. Replacing the silicon nitride floating gate of a conventional Flash NVM with QDSL gives rise to minibands that result in greater control over charge levels stored in the QDG and additional intermediate states. Utilizing Hot Carrier Injection (HCI) programming, for the realized device, various magnitudes of gate voltage pulses demonstrated the ability to accurately control the charge levels stored in the QDG. This corresponds to multiple threshold voltage shifts allowing detection of multiple states during read operations.


2006 ◽  
Vol 917 ◽  
Author(s):  
Mikael Casse ◽  
Laurent Thevenod ◽  
Bernard Guillaumot ◽  
Lucie Tosti ◽  
Vincent Cosnier ◽  
...  

AbstractWe have investigated the impact of a metal gate (TiN) and high-k dielectric (HfO2) on the carrier mobility. We have shown that strong remote Coulomb scattering (RCS) due to charges in the HfO2 layer (either grown by ALD or MOCVD) mostly degrades the mobility at low/medium field. High amount of charges (>1013cm-2) is needed to explain the 30% degradation observed in devices with a thin interface layer. These additional coulombic interactions are effective for bottom oxide up to 2nm. We have developed a RCS model to fully explain the experimental data. The influence of the metal gate is also evidenced. The latter has a significative impact on the Si/SiO2 interface roughness, and may induce some additional coulombic interactions.


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