Direct and trap-assisted elastic tunneling through ultrathin gate oxides

Abstract

The direct and assisted-by-trap elastic tunnel current in metal-oxide-semiconductor capacitors with ultrathin gate oxide ͑1.5-3.6 nm͒ has been studied. Bardeen's method has been adapted to obtain the assisted tunnel current, in addition to the direct tunnel current. The dependence of the assisted current on the trap distribution in energy has also been analyzed. This allows us to obtain the trap distribution in energy from experimental current curves. Finally, we have analyzed the role of the image force, the inclusion of which can avoid a barrier height dependence on the oxide thickness.

Elastic tunneling charge transport mechanisms in silicon quantum dots /SiO2 thin films and superlattices

“…Besides, we compared our fits and the resulting parameters fitted with the approach presented on Ref. 28. The authors of Ref.…”

“…The parameters used to describe the position and energy trap distribution functions are similar to the ones used in Ref. 28. We focused on the thickest active layers since, as Ref.…”

“…25 Moreover, the THF has been also used to describe the trap assisted tunneling in different degrees of sophistication. [26][27][28] However, up to now, nobody has presented a complete transport model capable to simulate large Qd arrays and traps (or defects) associate to the Qd formation or intrinsic to the dielectric matrix. In summary, theoretical models and experimental systems are still far from each other.…”

Efficient Silicon Light-Emitting-Diodes with a p-Si/Ultrathin SiO2/n-Si Structure

“…It was shown in [10] that the direct tunneling is dominant in SiO 2 /Si with ultrathin SiO 2 < 2.6 nm. At the SiO 2 /Si interface, there exist a valence band offset of 4.25 eV and a conduction band offset of 3.13 eV [11] making the tunneling possibility for holes much smaller than electrons.…”

“…The forward current of the former diode is clearly lower at same bias compared with the latter due to the insulate SiO 2 layer. In the p-Si/SiO 2 /n-Si diode, carriers may transport through the ultrathin SiO 2 layer by direct tunneling [10,11], which will be further described in next sections. Figure 2 shows the room temperature (RT) electroluminescence (EL) spectra taken from the p-Si front side of the two diodes with a forward current of 100 mA, respectively.…”