Enhancement-Mode LaLuO₃–AlGaN/GaN Metal–Insulator–Semiconductor High-Electron-Mobility Transistors Using Fluorine Plasma Ion Implantation

Abstract

Carbon monosulfide molecular ion (CS + ), which plays an important role in various research fields, has long been attracting much interest. Because of the unstable and transient nature of CS + , its electronic states have not been well investigated. In this paper, the electronic states of CS + are studied by employing the internally contracted multireference configuration interaction method, and taking into account relativistic effects (scalar plus spin-orbit coupling). The spinorbit coupling effects are considered via the state-interacting method with the full Breit-Pauli Hamiltonian. The potential energy curves of 18 Λ-S states correlated with the two lowest dissociation limits of CS + molecular ion are calculated, and those of 10 lowest Ω states generated from the 6 lowest Λ-S states are also worked out. The spectroscopic constants of the bound states are evaluated, and they are in good agreement with available experimental results and theoretical values. With the aid of analysis of Λ-S composition of Ω states at different bond lengths, the avoided crossing phenomena in the electronic states of CS + are illuminated. Finally, the single ionization spectra of CS (X 1 Σ + ) populating the CS + (X 2 Σ + 1/2 , A 2 Π 3/2 , A 2 Π 1/2 , and B 2 Σ + 1/2 ) states are simulated. The vertical ionization potentials for X 2 Σ + 1/2 , A 2 Π 3/2 , A 2 Π 1/2 , and B 2 Σ + 1/2 states are calculated to be 11.257, 12.787, 12.827, and 15.860 eV, respectively, which are accurate compared with previous experimental results, within an error margin of 0.08 eV∼0.2 eV.

Enhancement‐mode AlGaN/GaN HEMTs with thin and high Al composition barrier layers using O2 plasma implantation

“…With L GD = 10 µm, the catastrophic breakdown of the E‐mode HEMT occurs at a drain voltage of 450 V even measured in air (see Fig. c), which is, to the best of our knowledge, the highest value of the E‐mode HEMT fabricated using plasma oxidation technology and comparable to results obtained by other technologies with similar L GD . An enhanced breakdown performance can be expected when the large OFF‐state leakage current possibly originating from a stronger polarization electric field in Al‐rich barrier layer is further suppressed .…”

On Analysis of Topological Properties for Terbium IV Oxide via Enthalpy and Entropy Measurements

“…Terbium IV oxide films have huge application as an insulator in microelectronics, gas detectors, and luminophores due to unique properties such as radiation resistance and very small leakage current density besides variable electrical conductivity in different gaseous fluids [4,5]. It is found that various oxidation states cause changes in the stoichiometry of terbium IV oxide that predetermines variations in its optical properties, thus making it useful for the aforementioned applications as well as in Fresnel lenses, pigments, antireflection layers, and photoelastic films [6,7].…”

High-temperature studies of multiple fluorinated traps within an Al2O3gate dielectric for E-Mode AlGaN/GaN power MIS-HEMTs

“…A normally-off AlGaN/GaN HEMT device with a positive gate threshold voltage (V TH > 0) is desirable in power applications due to the benefits of system controllability. To make such devices, three techniques are available: the p-GaN (or p-AlGaN) cap layer [1,2], AlGaN barrier recess [3,4], and the fluorine ion (F − ) treatment [5][6][7][8][9]. The p-GaN cap layer is Mg-doped and located underneath the gate contact to form a p-n junction between the p-GaN and i-AlGaN layers and to deplete the two-dimensional electron gas (2DEG).…”

“…Thirdly, there is the fluorine treatment technique by incorporating negative charges in the gate dielectrics to deplete the 2DEG. The amount of negative charge incorporated by the fluorine treatment is the key to determine the level of V TH [5][6][7][8][9]. For the unannealed multiple F − treatments on the ALD-Al 2 O 3 gate dielectric combined with a partial AlGaN recess reported in [11], a high amount of F − incorporation at the gate stack was possible, which resulted in a high threshold voltage of +6.5 V, with satisfactory maximum drain current (I DMAX ) of 340 mA mm −1 and off-state breakdown voltage of 1130 V. However, a large swing in the gate threshold voltage is found when devices operate at elevated temperatures.…”