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In this work, we demonstrate the potential of a gallium nitride (GaN)-based visible-blind ultraviolet (UV) photodetector (PD) on a commercially viable 150-mm Si wafer. The influence of thermionic field emission (TFE) and Poole–Frenkel (PF) mechanisms on the current transport of the PD has been analyzed. Conduction due to the TFE mechanism dominates in the moderate electric fields (1.25 kV/cm ${ kV/cm), while the influence of PF is prominent at higher electric fields. A bulk trap energy level of 0.374 eV is obtained with PF conduction analysis. A high responsivity of 33.3 A/W at 15 V with a 362-nm incident wavelength has been achieved in the presence of an internal gain. The internal gain of the PD is also assisted by TFE and PF mechanisms. The PD exhibits a low dark current of 4.7 nA as well as high detectivity of $4.6\times 10^{12}$ Jones at the abovementioned bias. The demonstrated robustness and high performance show the promise of III–nitride PDs for commercial applications.

In this article, we report the temperature-dependent transistor characteristic of Epi-Gd2O3/AlGaN/GaN metal oxide semiconductor high electron mobility transistor (MOSHEMT) and compare its properties with that of AlGaN/GaN metal-Schottky high electron mobility transistor (HEMT) grown on 150 mm Si (111) substrate. Introducing an epitaxial single crystalline Gd2O3 between the metal gate and AlGaN barrier not only improves the gate leakage current significantly but also enhances its thermal stability. We observe that there is no significant change in the gate leakage current even at 473 K compared to that measured at room temperature (RT) (298 K), and this is also evident in the transistor’s subthreshold behavior at 473 K. We have determined the electric field within the Gd2O3 as well as AlGaN and investigated the leakage conduction mechanism through Gd2O3. The ${I}_{ \mathrm{ON}}/{I}_{ \mathrm{OFF}}$ of the transistor was measured as high as ~108 even at 473 K with the lowest ${V}_{\text {TH}}$ shift (91.4 mV) with temperature. Our measurements also confirm the presence of polar optical phonon scattering, which directly affects the 2-D electron gas (2DEG) mobility at high temperatures and thus the electrical characteristics of HEMT and MOSHEMT.

The role of post-growth cyclic annealing (PGCA) and subsequent regrowth, on the improvement of crystal quality and surface morphology of (111)-oriented Ge epitaxial layers, grown by low temperature (300 °C) molecular beam epitaxy on epi-Gd2O3/Si(111) substrates, is reported. We demonstrate that PGCA is efficient in suppressing rotational twins, reflection microtwins and stacking faults, the predominant planar defect types in Ge(111) epilayers. Continuing Ge growth after PGCA, both at low (300 °C) and high (500 °C) temperatures, does not degrade the crystal quality any further. By promoting adatom down-climb, PGCA is observed to also heal the surface morphology, which is further improved on Ge re-growth. These results are promising for development of high-quality Ge(111) epitaxial layers for photonic and electronic applications.

We report growth, structural, and electrical properties of epitaxial Ge layers on Si (001) wafers for next generation complementary metal oxide semiconductor devices. The epi-Ge layers were grown by solid source molecular beam epitaxy (MBE) at substrate temperatures (TG) varying from 200 degrees C to 500 degrees C. A two-step growth process, where an initial layer of thickness similar to 30 nm is grown at a substrate temperature of 250 degrees C (except those grown below/at 250 degrees C), and the remaining layer is grown at a higher temperature, was found to be an efficient approach to improve the crystal quality of the Ge layers. The epi-Ge on Si exhibits bulk hole-mobility as high as 736 cm(2)/V-s at room temperature. Ti/Ge/Ti metal semiconductor -metal (MSM) back-to-back Schottky diodes, fabricated on these epitaxial Ge layers, show excellent electrical properties. Further, metal oxide semiconductor (MOS) capacitors fabricated with HfO2 as the gate oxide exhibit low leakage current density of 4.7 x 10(-2) A/cm(2) (at Vg-VFB = 1 V) and mid-gap interface trap density of 5.0 x 10(12) cm(-2)eV(-1). (C) 2016 Elsevier B.V. All rights reserved.