Analytic model of direct tunnel current through ultrathin gate oxides

Khairurrijal, _; Mizubayashi, Wataru; Miyazaki, Seiichi; Hirose, Masataka

doi:10.1063/1.372290

Cited by 82 publications

(64 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Nevertheless, some studies had shown a contradicting effect: If the effective mass is supposed to be 0.5m e , then barrier height is obtained around 2.9-3.1 eV, 30,31 whereas if barrier height is taken to be as 3.1 eV then effective mass was found as 0.37m e . 32 Khairurrijal et al 33 showed from their theoretical calculations that the effective mass of electrons in SiO 2 oxide film increases when the oxide thickness gets decreased, having a value between 0.3m e and 0.9m e . Upon assuming constant electron effective mass at 0.5m e in oxide film, Hadjadj et al 22 added the effect of oxide thickness on electron affinity difference for 5, 7, and 12 nm thick oxides for the temperature ranging from 23 to 300°C.…”

Section: ͑8͒mentioning

confidence: 99%

“…16,33,34 It is shown that there is a conflict, if the effective mass is taken as a constant when calculating the barrier height, or if the barrier height is taken as a constant when calculating the effective mass. 15 Some researchers additionally tried to formulize the effective mass, and/or barrier height in terms of nitrogen percentage content in the oxide film.…”

Section: ͑8͒mentioning

confidence: 99%

See 1 more Smart Citation

Impact of temperature increments on tunneling barrier height and effective electron mass for plasma nitrided thin SiO2 layer on a large wafer area

Aygün

Roeder

Erlbacher

et al. 2010

Journal of Applied Physics

View full text Add to dashboard Cite

Thermally grown SiO 2 layers were treated by a plasma nitridation process realized in a vertical furnace. The combination of a pulsed-low frequency plasma and a microwave remote plasma with N 2 / NH 3 / He feed gas mixture was used to nitride the thermally grown SiO 2 gate dielectrics of MIS structures. Temperature dependency of effective masses and the barrier heights for electrons in pure thermally grown SiO 2 as well as plasma nitrided SiO 2 in high electric field by means of FowlerNordheim regime was determined. It is frequently seen from the literature that either effective electron mass or barrier height ͑generally effective electron mass͒ is assumed to be a constant and, as a result, the second parameter is calculated under the chosen assumption. However, in contrast to general attitude of previous studies, this work does not make any such assumptions for the calculation of neither of these two important parameters of an oxide at temperature ranges from 23 to 110°C for SiO 2 , and 23 to 130°C for nitrided oxide. It is also shown here that both parameters are affected from the temperature changes; respectively, the barrier height decreases while the effective mass increases as a result of elevated temperature in both pure SiO 2 and plasma nitrided SiO 2 . Therefore, one parameter could be miscalculated if the other parameter, i.e., effective mass of electron, was assumed to be a constant with respect to variable physical conditions like changing temperature. Additionally, the barrier heights were calculated just by taking constant effective masses for both types of oxides to be able to compare our results to common literature values.

show abstract

Section: ͑8͒mentioning

confidence: 99%

Section: ͑8͒mentioning

confidence: 99%

Impact of temperature increments on tunneling barrier height and effective electron mass for plasma nitrided thin SiO2 layer on a large wafer area

Aygün

Roeder

Erlbacher

et al. 2010

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…Two electron masses enter this equation: the density-of-states mass in the plane parallel to the interface m 3D = 2m and m * t = 0.19m 0 equals 2.052m 0 , and the electron mass in the dielectric m diel , which is commonly used as fit parameter [3]. However, in the channel of inverted MOS devices, the strong electric field leads to quantum confinement and the assumption of continuum tunneling is no more justified.…”

Section: Tunneling From Continuum Versus Quasi-bound Statesmentioning

confidence: 99%

On the Calculation of Quasi-Bound States and Their Impact on Direct Tunneling in CMOS Devices

Gehring¹,

Selberherr²

2004

Simulation of Semiconductor Processes and Devices 2004

View full text Add to dashboard Cite

We study the calculation of quasi-bound states in nMOS inversion channels and their impact on direct tunneling currents through the dielectric layer. For typical device parameters, the gate leakage in inversion is dominated by this tunneling component. However, a strong inaccuracy arises, if the eigenvalues of the closed system are used for the quasi-bound state tunneling current. We propose simple correction functions to the closed-boundary eigenvalues calculated by the triangular approximation which allows to account for both, continuum and quasi-bound state tunneling in an efficient manner.

show abstract

“…The electron transmittance was then used to calculate leakage current j z by using the standard equation as written in Eq. (3) [11].…”

Section: Theoretical Modelmentioning

confidence: 99%

Theoretical Study on Leakage Current in MOS with High-K Dielectric Stack: Effects of In-plane-Longitudinal Kinetic Energy Coupling and Anisotropic Masses

Khairurrijal

Noor

Abdullah

et al. 2009

Trans. Mat. Res. Soc. Japan

View full text Add to dashboard Cite

A model of leakage current in Al/HfO 2 /SiO 2 /Si MOS (metal-oxide-semiconductor) capacitors is given by adopting the tunnel current model in SiGe-based heterojunction bipolar transistors. The velocity of an electron in the metal gate, which originates from the coupling between longitudinal and transverse (in-plane) kinetic energies, and the anisotropic mass of the substrate were included in the leakage current model. It was found that the leakage current obtained by including the gate electron velocity is lower than that calculated without the coupling effect and the leakage current decreases with an increasing gate electron velocity. However, the leakage current is not significantly influenced by the silicon substrate orientation. If a measured leakage current in the high-K dielectric stack MOS with Si(100) substrate were much higher than that in the MOS with Si(111) as observed in the conventional MOS, then the gate electron phase velocity in the latter would be higher. A small increase of the equivalent oxide thickness (EOT) of HfO 2 will decrease the tunnel current appreciably and tunnel current oscillations become visible as the EOT becomes thicker. Oscillatory behavior of the tunnel current is due to resonance states in the quantum well formed in high-K dielectric stack at high electric fields.

show abstract

Analytic model of direct tunnel current through ultrathin gate oxides

Cited by 82 publications

References 29 publications

Impact of temperature increments on tunneling barrier height and effective electron mass for plasma nitrided thin SiO2 layer on a large wafer area

Impact of temperature increments on tunneling barrier height and effective electron mass for plasma nitrided thin SiO2 layer on a large wafer area

On the Calculation of Quasi-Bound States and Their Impact on Direct Tunneling in CMOS Devices

Theoretical Study on Leakage Current in MOS with High-K Dielectric Stack: Effects of In-plane-Longitudinal Kinetic Energy Coupling and Anisotropic Masses

Contact Info

Product

Resources

About