HYSTERESIS-LIKE FLATBAND VOLTAGE INSTABILITIES IN Al/Ta2O5-SiO2/Si STRUCTURES AND THEIR CONNECTION WITH J-V CHARACTERISTICS

Nenad Novkovski, Albena Paskaleva, Elena Atanassova

Abstract


Flatband and current-voltage instabilities in unstressed Al/Ta2O5-SiO2/Si structures were studied in details. It has been found that, after an initial run left on fresh samples, both C-V and J-V characteristics exhibit repeatable patterns. Precisely repeatable counterclockwise hysteresis-like loop in C-V characteristics occurs, while no significant hysteretic behaviour is observed in static J-V characteristics. The reduced instability in J-V characteristics is explained by mutual compensation of two opposite effects owing to the presence of trapped positive charges on slow traps in the interfacial SiO2-like layer: (i) flatband voltage shift and (ii) lowering of Fowler-Nordheim tunnelling barrier for holes injected from the Si substrate. Correct determination of equivalent oxide thickness and fast interface state densities requires using the C-V curves obtained during the runs right, because progressive trapping on slow states occurs during the runs left. Value of the oxide charge is to be determined using the value of the flatband voltage obtained from the run left (after an initial run right), since it corresponds to the state of empty slow traps.

Keywords


C-V hystersis; nanosized dielectric films; interface silicon/silicon dioxide

Full Text:

PDF

References


J. Robertson, High dielectric constant gate oxides for metal oxide Si transistors, Rep. Prog. Phys., 69 (2006), pp. 327–396.

G. Ribes, J. Mitard, M. Denais, S. Bruyere, F. Monsieur, C. Parthasarathy, E. Vincent, G. Ghibaudo, Review on high-k dielectrics reliability, issues, IEEE Trans. Device Mater. Reliab., 5 (2005), pp. 5–19.

Q.-Q. Sun, A. Laha, S.-J. Ding, D. W. Zhang, H. J. Osten, A. Fissel, Effective passivation of slow interface states at the interface of single crystalline Gd2O3 and Si(100), Appl. Phys. Lett., 92 (2008), 152908 (3 pages).

C. Petit, D. Zander, K. Lmimouni, M. Ternisien, D. Tondelier, S. Lenfant, D. Vuillaume, Gate pulse electrical method to characterize hysteresis phenomena in organic field effect transistor, Organic Electronics, 9 (2008), pp. 979–984.

M. B. Zahid, L. Pantisano, R. Degraeve, M. Aoulaiche, L. Trojman, I. Ferain, E. S. Andrés, A. Shickova, R. O'Connor, G. Groeseneken, M. Heyns, S. D. Gendt, Trapping in 1nm EOT high-k / MG, ECS Trans., 16 (2009), pp. 77–84.

S. Dueñas, H. Castán, H. García, A. Gómez, L. Bailón, K. Kukli, J. Aarik, M. Ritala, M. Leskelä, Comparative study of flatband voltage transients on high-k dielectric-based metal-insulator-semi-conductor capacitors, J. Electrochem. Soc., 155 (2008), pp. G241–G246.

T.-M. Pan, S.-J. Hou, Silicon-oxide-nitride-oxide-silicon-type flash memory with a high-k NdTiO3 charge trapping layer, Appl. Phys. Lett., 92 (2008), 072907 (3 pages).

H.-S. Kim, I. Ok, M. Zhang, F. Zhu, S. Park, J. Yum, H. Zhao, J. C. Lee, J. Oh, P. Majhi, Flat-band voltage instability characteristics of HfO2-based GaAs metal-oxide-semiconductor capaci-tors with a thin Ge layer, Appl. Phys. Lett., 92 (2008), 102904 (3 pages).

E.-A. Choi, K. J. Chang, Charge-transition levels of oxygen vacancy as the origin of device instability in HfO2 gate stacks through quasi-particle energy calculations, Appl. Phys. Lett., 94 (2009), 122901 (3 pages).

H.-K. Noh, B. Ryu, E.-A. Choi, J, Bang, K. J. Chang, Local bonding effect on the defect states of oxygen vacancy in amorphous HfSiO4, Appl. Phys. Lett., 95 (2009), 082905 (3 pages).

C. Li, F. Pan, X. Wang, L. Wang, H. Wang, H. Wang, D. Yan, Effect of the work function of gate electrode on hysteresis characteristics of organic thin-film transistors with Ta2O5/polymer as gate insulator, Organic Electronics, 10 (2009), pp. 948–953.

R. M. Fleming, D. V. Lang, C. D. W. Jones, M. L. Steigerwald, D. W. Murphy, G. B. Alers, Y.-H. Wong, R. B. van Dover, J. R. Kwo, A. M. Sergent, Defect dominated charge transport in amorphous Ta2O5 thin films, J. Appl. Phys., 88 (2000), pp. 850–862.

J.-P. Manceau, S. Bruyere, S. Jeannot, A. Sylvestre, P. Gonon, Metal-insulator-metal capacitors’ current instability improvement using dielectric stacks to prevent oxygen vacancies formation, Appl. Phys. Lett., 91 (2007), 132907 (3 pages).

J. R. Jameson, W. Harrison, P. B. Griffin, J. D Plummer, Double-well model of dielectric relaxation current, Appl. Phys. Lett., 84 (2004), pp. 3489–3491.

J. R. Jameson, W. Harrison, P. B. Griffin, J. D. Plummer, Y. Nishi, A semiclassical model of dielectric relaxation in glasses, J. Appl. Phys., 100 (2006), 124104 (20 pages).

K. Iwamoto, Y. Kamimuta, A. Ogawa, Y. Watanabe, S. Migita, W. Mizubayashi, Y. Morita, M. Takahashi, H. Ota, T. Nabatame, A. Toriumi, Experimental evidence for the flatband voltage shift of high-k metal-oxidesemiconductor devices due to the dipole formation at the high-k/SiO2 interface, Appl. Phys. Lett., 92 (2008), 132907 (3 pages).

K. B. Jinesh, Y. Lamy, J. H. Klootwijk, W. F. A. Besling, Maxwell–Wagner instability in bilayer dielectric stacks, Appl. Phys. Lett., 95 (2009), 122903 (3 pages).

Y. Fukuda, Y. Otani,T. Sato, H. Toyota, T. Ono, Effects of postdeposition annealing ambient on hysteresis in an Al2O3/GeO2 gate-dielectric stack on Ge, J. Appl. Phys.,110 (2011), 026108 (3 pages).

H. Nakashima, Y. Iwamura, K. Sakamoto, D Wang, K. Hirayama, K. Yamamoto, H. Yang, Postmetallization annealing effect of TiN-gate Ge metal-oxidesemiconductor capacitor with ultra-thin SiO2/GeO2 bilayer passivation, Appl. Phys. Lett., 98 (2011), 252102 (3 pages).

J. R. Jameson, P. B. Griffin, D. Plummer, Y. Nishi, Charge Trapping in High-k Gate Stacks Due to the Bilayer Structure Itself, IEEE Trans. Electron. Dev., 53 (2006), pp. 1858–1867.

E. Atanassova, T. Dimitrova, pp. 439-479 in “Handbook of surfaces and interfaces of materials” Edited by Hari Singh Naiwa, 4 (Academic Press – San Diego 2001).

E. Atanassova, D. Spasov, Thermal Ta2O5 – alternative to SiO2 for storage capacitor application, Microelectron. Reliab., 42 (2002), pp. 1171–1177.

G. S. Oehrlein, Capacitance-voltage properties of thin Ta2O5 films on silicon, Thin Solid Films, 156 (1988), pp. 207-320.

J.-G. Hwu, M.-J. Jeng, W.-S. Wang, Y.-K. Tu, Clockwise C/V hysteresis phenomena of metal–tantalum-oxide–silicon-oxide–silicon (p) capa-citors due to leakage current through tantalum oxide, J. Appl. Phys., 62 (1987), 4277 (7 pages).

E. Atanassova, A. Paskaleva, Challenges of Ta2O5 as high-k dielectric for nanoscale DRAMs, Microelectron. Reliab., 47 (2007), pp. 913–923.

N. Novkovski, E. Atanassova, Injection of holes from the silicon substrate in Ta2O5 films grown on silicon, Appl. Phys. Lett., 85 (2004), pp. 3142–3144.

N. Novkovski, E. Atanassova, A comprehensive model for the I–V characteristics of metal-Ta2O5/SiO2-Si structures, Appl. Phys. A, 83 (2006), pp. 435–445.

N. Novkovski, E. Atanassova, Origin of the stress-induced leakage currents in Al–Ta2O5 /SiO2–Si structures, Appl. Phys. Lett., 86 (2005), 152104 (3 pages).

E. Atanassova, A. Paskaleva, N. Novkovski, Effects of the metal gate on the stress-induced traps in Ta2O5/SiO2 stacks, Microelectron. Reliab., 48 (2008), pp. 514–525.

S. Kar, S. Rawat, S. Rakheja, D. Reddy, Characterization of Accumulation Layer Capa-citance for Extracting Data on High-k GateDielectrics, IEEE Trans. Electron Devices, 52 (2005), pp. 1187–1193.

J. T. Ryan, R. G. Southwick, J. P. Campbell, K. P. Cheung, C. D. Young, J. S. Suehle, On the "U-shaped" continuum of band edge states at the Si/SiO2 interface, Appl. Phys. Lett., 99 (2011), 223516 (3 pages).

M. Houssa, M. Tuominen, N. Naili, V. Afanas’ev, A. Stesmans, S. Haukka, M. M. Heyns, Trap-assisted tunneling in high permittivity gate di-electric stacks, J. Appl. Phys., 87 (2000), pp. 8615–8620.

W. S. Lau, L. L. Leong, T. Han, N. P. Sandler, Detection of oxygen vacancy defect states in capacitors with ultrathin Ta2O5 films by zero-bias thermally stimulated current spectroscopy, Appl. Phys. Lett., 83 (2003), pp. 2835–2837.

W. S. Lau, T. Han, General theory of acceptor-oxygen-vacancy complex single donor in high-dielectric-constant metallic oxide insulators, Appl. Phys. Lett., 86 (2005), 152107 (3 pages).

W. S. Lau, L. Zhong, A. Lee, C. H. See, T. Han, N. P. Sandler, T. C. Chong, Detection of defect states responsible for leakage current in ultrathin tantalum pentoxide (Ta2O5) films by zero-bias thermally stimulated current spectroscopy, Appl. Phys. Lett., 71 (1997), pp. 500–502.

S. M. Sze, Physics of semiconductor devices, 2nd edition, Willey, New York (1981).

M. Houssa, T. Nigam, P. W. Mertens, M. M. Heyns, Soft breakdown in ultrathin gate oxides: Correlation with the percolation theory of nonlinear conductors, Appl. Phys. Lett., 73 (1998), pp. 514–516.

J. A. Rothschild, H. Avraham, E. Lipp, M. Eizenberg, Tunneling of holes observed at work function measurements of metal/HfO2/SiO2/n-Si gate stacks, Appl. Phys. Lett., 96 (2010), 122102 (3 pages).

K. Maitra, N. Bhat, Analytical approach to integrate the different components of direct tunneling current through ultrathin gate oxides in n-channel metal–oxide–semiconductor field-effect transistors, J. Appl. Phys., 93 (2003), pp. 1064–1068.




DOI: http://dx.doi.org/10.20903/csnmbs.masa.2013.34.1-2.38

Refbacks

  • There are currently no refbacks.


Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.



Contact details

Bul. Krste Misirkov br.2
1000 Skopje, Republic of Macedonia
Tel. ++389 2 3235-400
cell:++389 71 385-106
mail: manu@manu.edu.mk
About the journal

CSNMBS is a part of the MASA Contribution series. Published by the Section Natural, Mathematical and Biotechnical Sciences.
About this site

Maintained by the Researh center for Materials and Enviroment - MANU/MASA.
Site (including the theme) set, adapted by MASA - CSIT.