Schottky barrier

About: Schottky barrier is a research topic. Over the lifetime, 22570 publications have been published within this topic receiving 427746 citations. The topic is also known as: Schottky barrier junction.

Band offsets and Schottky barrier heights of high dielectric constant oxides

Abstract: Oxides with higher dielectric constants are required to act as gate dielectrics for future generations of electronic devices. The electronic structure and band offsets of the oxides on Si have been calculated for many candidate gate oxides using the local density formalism pseudopotential method. The predicted conduction band offsets are similar to those found earlier using the tight-binding method, and where available, with experimental values found by photoemission and internal photoemission. The oxides which are acceptable as gate oxides in terms of their band offsets are ZrO2, HfO2, La2O3, Y2O3, Al2O3, silicates such as ZrSiO4 and HfSiO4 and aluminates such as LaAlO3.

WSe2 field effect transistors with enhanced ambipolar characteristics

Abstract: One of the most relevant features that a semiconducting channel material can offer when used in a field-effect transistor (FET) layout is its capability to enable both electron transport in the conduction band and hole transport in the valence band. In this way, complementary metal-oxide-semiconductor type applications become feasible once similar electron and hole drive current densities are achieved, and the threshold voltages are properly adjusted. In this article, we demonstrate pronounced ambipolar device characteristics of multilayer WSe2 FETs using different contact electrodes. Our study reveals that nickel electrodes facilitate electron injection while palladium electrodes are more efficient for hole injection. We also show, as an interesting demonstration, that by using nickel as the source contact electrode and palladium as the drain contact electrode, ambipolar device characteristics with similar on-state performance for both the electron and the hole branch can be achieved in WSe2 FETs. Finally, we discuss a unique technique based on the asymmetry in the ambipolar device characteristics to extract the Schottky barrier heights for such metal to WSe2 contacts.

Schottky-Barrier Formation at Single-Crystal Metal-Semiconductor Interfaces

Abstract: Electrical behaviors at two single-crystal metal-semiconductor interfaces are studied. Schottky-barrier heights of NiSi2layers grown under ultrahigh-vacuum conditions on n- type Si(111) are found to be 0.65 and 0.79 eV for type-Aand type-Bepitaxial systems, respectively. These results are compared with the proposed theoretical models of Schottky barriers.

The Richardson constant for thermionic emission in Schottky barrier diodes

Abstract: The Richardson equation appropriate to thermionic emission in Schottky barrier diodes is derived. For a semiconductor having an energy band with ellipsoidal constant-energy surfaces in momentum space, the Richardson constant A 1 ∗ associated with a single energy minimum is A ∗ 1 =4φ qk 2 h 3 (l 2 m y m z +m 2 m z m x +n 2 m x m y ) 1 2 where l, m and n are the direction cosines of the normal to the emitting plane relative to the principal axes of the ellipsoid and mx, my and mz are the components of the effective mass tensor. In the Ge conduction band, summation of emission from all the energy minima gives maximum and minimum ratios of A∗ to the free electron value A (= 120 A/cm2/°K2) of 1·19 and 1·07 for the 〈100〉 and 〈111〉 directions respectively. In the silicon conduction band, maximum and minimum ratios of 2·15 and 2·05 occur for the 〈111〉 and 〈100〉 directions respectively. The theoretical predictions are in good agreement with experimental results from W-Si and Au-GaAs diodes.

Schottky barrier heights of tantalum oxide, barium strontium titanate, lead titanate, and strontium bismuth tantalate

Abstract: The Schottky barrier heights of various metals on the high permitivity oxides tantalum pentoxide, barium strontium titanate, lead zirconate titanate, and strontium bismuth tantalate have been calculated as a function of the metal work function. It is found that these oxides have a dimensionless Schottky barrier pinning factor S of 0.28–0.4 and not close to 1 because S is controlled by Ti–O-type bonds not Sr–O-type bonds, as assumed in earlier work. The band offsets on silicon are asymmetric with a much smaller offset at the conduction band, so that Ta2O5 and barium strontium titanate are relatively poor barriers to electrons on Si.