Recent years have witnessed GaN-based devices delivering their promise of unprecedented power and frequency levels demonstrating capability as an able replacement for Si-based devices. High-electron-mobility transistors (HEMTs), a key representative architecture devices, are well-suited high-power high device applications, owing to highly desirable III-nitride physical properties. However, these still hounded by issues not previously encountered in more established Si- GaAs-based...

Abstract In this paper, we give an overview of the recent progress in GaN-based high-electron-mobility transistors (HEMTs) developed for mainstream acceptance power electronics field. The comprehensive investigation AlGaN/GaN HEMTs fabricated on a free-standing semi-insulating GaN substrate reveals that extracted effective lateral breakdown field approximately 1 MV/cm is likely limited by premature device originating from insufficient structural and electrical quality buffer layers and/or...

Interface characterization was carried out on Al2O3/GaN structures using epitaxial n-GaN layers grown free-standing GaN substrates with relatively low dislocation density (<3 × 106 cm−2). The Al2O3 layer prepared by atomic deposition. as-deposited metal-oxide-semiconductor (MOS) sample showed a significant frequency dispersion and bump-like feature in capacitance-voltage (C–V) curves at reverse bias, showing high-density interface states the range of 1012 cm−1 eV−1. On other hand,...

Gallium nitride (GaN) is one of the front-runner materials among so-called wide bandgap semiconductors that can provide devices having high breakdown voltages and are capable performing efficiently even at temperatures. The bandgap, however, naturally leads to a density surface states on bare GaN-based or interface along insulator/semiconductor interfaces distributed over energy range. These electronic lead instabilities other problems when not appropriately managed. In this Tutorial, we...

We develop and characterize multi-mesa-channel (MMC) AlGaN/GaN high-electron mobility transistors (HEMTs), in which a periodic trench structure is fabricated only under the gate electrode. A surrounding-field effect MMC results shallower threshold voltage smaller subthreshold slope than those of standard planar-type HEMT. In addition, HEMT shows low knee weak dependence on-resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> )...

This paper presents a systematic characterization of electronic states at insulators/(Al)GaN interfaces, particularly focusing on insulator/AlGaN/GaN structures. First, we review important results reported for GaN metal–insulator–semiconductor (MIS) SiO2 is an attractive material MIS transistor applications due to its large bandgap and high chemical stability. In-situ SiNx effective improving the operation stability electron mobility transistors (HEMTs). Meanwhile, Al2O3/GaN structures have...

We report on an Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /AlGaN/GaN metalinsulator-semiconductor high-electron-mobility transistor (MIS-HEMT) with recessed-gate structure and regrown AlGaN barrier. After analyzing the possibility of obtaining high threshold voltage (V xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) within framework Tapajna Kuzmik model from preliminary...

Abstract We demonstrate normally-off operation in Al 2 O 3/AlGaN/GaN MIS-HEMTs with a high two dimensional electron gas (2DEG) mobility enabled by shallow recess channel structure and oxygen plasma treatment. In the region, original 25-nm-thick AlGaN barrier layer was thinned down to 9 nm, which principle, should yield normally-on operation. However, we show that pre-insulator deposition treatment shifts threshold voltage +1.4 V. The relatively thick facilitated minimal sacrifice of 2DEG...

The structure of a ZnSnAs2 thin film epitaxially grown on an InP substrate was evaluated using x-ray fluorescence holography. reconstructed three-dimensional atomic images clearly show that the crystal is mainly sphalerite type, in contrast to bulk form. A large disordering As layers observed, whereas positions Zn/Sn atoms are relatively stable. analysis data indicates serve as buffer and relax strain caused by random occupation Zn Sn atoms. These results provide further understanding means...

Dramatic reduction of thermal resistance was achieved in AlGaN/GaN Multi-Mesa-Channel (MMC) high electron mobility transistors (HEMTs) on sapphire substrates. Compared with the conventional planar device, MMC HEMT exhibits much less negative slope ID-VDS curves at VDS regime, indicating self-heating. Using a method proposed by Menozzi and co-workers, we obtained 4.8 K-mm/W ambient temperature ∼350 K power dissipation ∼9 W/mm. This value compares well to 4.1 K-mm/W, which is HEMTs expensive...

We have demonstrated for the first time a remarkable reduction of current collapse in AlGaN/GaN high-electron-mobility transistors (HEMTs) by high-pressure water vapor annealing (HPWVA). The device subjected to HPWVA exhibited considerably low dynamic ON-resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> ), suggesting highly improved performance these devices. Analyses results on normalized R experiments shown elimination...

Effects of the ultrathin 1 nm thick AlGaN regrown layer before gate insulator deposition on performance ZrO 2 /AlGaN/GaN metal‐insulator‐semiconductor (MIS) structures are investigated. In comparison with reference MIS high‐electron‐mobility transistors (MIS‐HEMTs), MIS‐HEMTs exhibit increased maximum drain current (&gt;1050 mA mm −1 ) and broader full‐width at half (FWHM) transconductance profile (11 V). Moreover, leakage in forward direction is reduced by about four orders magnitude while...

We studied the effects of pre-passivation oxygen plasma treatment AlGaN surface on current collapse AlGaN/GaN high-electron-mobility transistors (HEMTs). Oxygen plasma-treated devices generally exhibited significantly less dynamic on-resistance (Ron) compared with untreated control devices. also extended our investigation to HEMTs a GaN cap layer. Interestingly, after treatment, we found that GaN-capped showed Ron behavior was essentially similar uncapped HEMTs, suggesting layer plays an...

Abstract This letter describes DC characteristics of AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) with Al 2 O 3 deposited by atomic layer deposition (ALD) as gate dielectric. Comparison was made for the samples using ozone (O ) or water oxidant. The effect pretreatment, where solely supplied prior to depositing , also investigated. MIS-HEMT pretreatment and dielectric oxidant exhibited most desirable an excellent high on/off current ratio 7.1 × 10 a...

Abstract We have investigated the effects of inductively coupled plasma (ICP) etching AlGaN surface on resulting interface properties Al 2 O 3 /AlGaN/GaN structures. The experimentally measured capacitance–voltage ( C – V ) characteristics were compared with those calculated taking into account states density at /AlGaN interface. As a complementary method, photoassisted method utilizing photons energies less than bandgap GaN was also used to probe state located near midgap. It found that ICP...

Abstract We report on the highly reduced current collapse in AlGaN/GaN high-electron-mobility transistors (HEMTs) by combined application of pre-passivation oxygen (O 2 ) plasma treatment and gate field plate (FP) structures schemes. Four different devices were fabricated this work: (1) conventional HEMT as reference device, (2) field-plated HEMT, (3) O plasma-treated (4) both HEMT. Analysis dependence normalized dynamic R (NDR) pulse on-time ( t revealed that gate-FP reduces emission time...

Abstract We report on the fabrication and characterization of AlGaN/GaN metal-insulator-semiconductor (MIS) capacitors high-electron-mobility transistors (MIS-HEMTs) using a 5 nm thick Al 2 O 3 dielectric deposited by cost-effective environmental-friendly mist chemical vapor deposition (mist-CVD) technique. Practically hysteresis-free capacitance–voltage profiles were obtained from fabricated two-terminal MIS-capacitors indicating high quality mist-Al /AlGaN interface. Compared with...

ZnSnAs2 thin films were prepared by molecular beam epitaxy (MBE) on semi-insulating (001) InP substrates using the same growth conditions as previously reported. High-resolution X-ray diffractometry (HRXRD) and Raman spectroscopy studies suggest presence of both chalcopyrite sphalerite phases. The transport properties measured from 5 K up to room temperature. We observed a pronounced peak in Hall coefficient temperature dependence curve at ∼130 K, similar those only chalcopyrite-phase bulk...

ZnSnAs2 epitaxial film has been grown on epi-ready semi-insulating InP(001) substrates by low-temperature molecular beam epitaxy (LT-MBE) technique. The MBE-grown sample was then cleaved into pieces, three of which were subjected to lowtemperature annealing at different temperatures 300 ∘C, 320 ∘C and 340 are equal or slightly higher than growth temperature using face-to-face proximity capping GaAs wafers simulate arsenic atmosphere. HR-XRD measurements showed that increasing decreases the...

Abstract The previously reported transport properties data of the undoped ZnSnAs 2 grown on semi‐insulating InP substrates by molecular beam epitaxy (MBE) have been reviewed and analysed. We found out that temperature dependence Hall coefficient resistivity can be well explained impurity band model proposed Isomura Tomioka. By using said model, we were able to resolve experimentally obtained carrier concentration p exp mobility μ into valence v with acceptor a . computed apparent values app...

ZnSnAs2 epitaxial films were grown by molecular beam epitaxy (MBE) on nearly lattice matched InP substrates. Four samples namely A, B, C, and D prepared at different growth times of 15, 30, 50, 83 mins, respectively, using the optimum conditions earlier reported to obtain values thickness for purpose structural characterization High-Resolution X-ray Diffraction (HR-XRD). HR-XRD investigations revealed unrelaxed constant a⊥ along direction 5.8991 Å, 5.8886 5.8928 Åfor D, respectively....