Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Q. L. Gu, C. Ling, G. Brauer, W. Anwand, Skorupa, Y. F. Hsu, A. B. Djurišić, Zhu, S. Fung, Lu; Deep level defects in a nitrogen-implanted ZnO homogeneous p-n junction. Appl. Phys. Lett. 2 June 2008; 92 (22): 222109. https://doi.org/10.1063/1.2940204 Download citation file: Ris (Zotero) Reference Manager EasyBib...

We report on high electric field stress measurements at room temperature InAlN/AlN/GaN heterostructure effect transistor structures. The degradation rate as a function of the average electron density in GaN channel (as determined by gated Hall bar for particular gate biases used), has minimum densities around 1×1013 cm−2, and tends to follow hot phonon lifetime dependence density. observations are consistent with buildup longitudinal optical phonons their ultrafast decay about same channel....

As-doped ZnO films were grown by the radio frequency magnetron sputtering method. As substrate temperature during growth was raised above ∼400 °C, changed from n type to p type. Hole concentration and mobility of ∼6×1017 cm−3 ∼6 cm2 V−1 s−1 achieved. The studied secondary ion mass spectroscopy, x-ray photoelectron spectroscopy (XPS), low photoluminescence (PL), positron annihilation (PAS). results consistent with AsZn–2VZn shallow acceptor model proposed Limpijumnong et al. [Phys. Rev. Lett....

We report on electron velocities deduced from current gain cutoff frequency measurements GaN heterostructure field effect transistors (HFETs) with InAlN barriers Fe-doped semi-insulating bulk substrates. The intrinsic transit time is a strong function of the applied gate bias, and minimum occurs for biases corresponding to two-dimensional gas densities near 9.3×1012 cm−2. This value correlates independently observed density giving longitudinal optical phonon lifetime. expect velocity, which...

We utilized low-frequency noise measurements to probe electron capture and emission from the traps in AlGaN/GaN heterostructure field-effect transistors as a function of drain bias. The excess noise-spectra due generation-recombination effect shifted higher frequency with elevated temperature room up 446 K. These dependent were carried out for four different drain-bias values 4 16 V increments. shift excess-noise was also seen increasing characteristic recharging times trapped electrons...

We report on the low-frequency phase-noise measurements of AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors employing HfAlO as gate dielectric. Some devices tested exhibited noise spectra deviating from well-known 1/f <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">γ</sup> spectrum. These showed broad peaks in spectral density versus frequency plots, which shifted toward higher frequencies at elevated temperatures....

In15.7%Al84.3%N/AlN/GaN heterojunction field effect transistors have been electrically stressed under four different bias conditions: on-state-low-field stress, reverse-gate-bias off-state-high-field and on-state-high-field in an effort to elaborate on hot electron/phonon thermal effects. DC current phase noise measured before after the stress. The possible locations of failures as well their influence electrical properties identified. stress causes trap generation around gate area near...

Tunable dielectric properties of epitaxial ferroelectric Ba0.5Sr0.5TiO3 (BST) thin films deposited on nearly lattice-matched DyScO3 substrates by radio frequency magnetron sputtering have been investigated at microwave frequencies and correlated with residual compressive strain. To reduce the strain BST caused substrate clamping improve their properties, a three-step deposition method was devised employed. A high-temperature 1068 K nucleation layer followed relatively low-temperature (varied...

Unintentionally doped n-type zinc oxide (ZnO) single crystal was implanted by arsenic ions with fluence of 10^1^4cm^-^2 at room temperature followed post-implantation annealing up to 900^oC. Rectifying property not observed in the As-implanted or annealed samples. Au Schottky contact fabricated on samples H2O2 pre-treatment. Deep-level transient spectroscopy measurements were performed contacts study deep-level defects and their thermal evolution.

Arsenic doped ZnO and ZnMgO films were deposited on SiO2 using radio frequency magnetron sputtering ZnO–Zn3As2 ZnO–Zn3As2–MgO targets, respectively. It was found that thermal activation is required to activate the formation of p-type conductivity. Hall measurements showed with a hole concentration ∼1017 cm−3 mobility ∼8 cm2 V−1 s−1 obtained at substrate temperatures 400–500 °C. The shallow acceptor mechanism investigated x-ray photoelectron spectroscopy, positron annihilation, low...

The resistivity of hydrothermally grown ZnO single crystals increased from ∼103 Ω cm to ∼106 after 1.8 MeV electron irradiation with a fluence ∼1016 cm−2, and ∼109 as the ∼1018 cm−2. Defects in samples were studied by thermally stimulated current (TSC) spectroscopy positron lifetime (PLS). After 1018 normalized TSC signal factor ∼100. A Zn vacancy was also introduced irradiation, though concentration lower than expected. annealing air at 400 °C, deep traps concentrations recovered levels...

Gallium Nitride on Silicon (GaN-on-Si) devices feature a relatively thick epi buffer layer to release the stress related lattice constant mismatch between GaN and Si. The is formed by several AlGaN-based transition layers with different Al contents. This work addresses fundamental question of whether two-dimensional hole gases (2DHGs) exist at those interfaces where theory predicts high concentration negative fixed charge as consequence discontinuity in polarization layers. In this study, we...

Six-fold helium ion implantation was carried out on nitrogen doped n-type 6H–SiC epi samples. A box-shaped He-implantation profile and damage region thus introduced. Vacancy-type defects in the implanted were studied by positron annihilation spectroscopy using a monoenergetic beam. The average size of vacancy-type defect detected as-He-implanted sample divacancy (V2). Thermal annealing had effect shrinking defective region. Annealing at temperatures lower than 900 °C removing While...

Abstract Generation‐recombination processes in AlGaN/GaN metal‐oxide‐semiconductor heterostructure field‐effect transistors (MOSHFETs) with HfAlO gate dielectric has been investigated through low‐frequency phase‐noise. Some devices tested exhibited noise spectra deviating from the well‐known (1/ f γ )spectrum. These showed broad peaks attributed to generation‐recombination (GR) noise‐spectral‐density vs. frequency plots, which shifted toward higher frequencies at elevated temperatures. The...

AlGaN/GaN heterojunction field effect transistors (HFETs) with 2 μm gate length were subjected to on-state-high-field (high drain bias and current) reverse-gate-bias (no current reverse bias) stress at room elevated temperatures for up 10 h. The resulting degradation of the HFETs was studied by direct uniquely phase noise before after stress. A series voltages applied during conditions, respectively, examine electric on HFET devices passivated SiNx. behaviors under these two types conditions...

We report on the evolution of AlGaN/GaN-based heterojunction field-effect transistor (HFET) operation under high-electric-field stress. Specifically, a 10 ~ 15 dB decrease in flicker noise is observed after stress contrast with what has been nominally and reported literature realm direct-current characteristics. Gate lag measurements revealed trap state an activation energy 0.20 eV pristine devices, which manifests itself as generation-recombination peak spectrum. This becomes undetectable...

We report on the low-frequency noise (LFN) measurements GaN based heterostructure field-effect transistors (HFETs) sapphire with InAlN and AlGaN barriers to investigate effects of electrical stress. The HFETs barrier undergone a DC stress at bias conditions V_DS=20V V_G= -4.5 for up 4 hours in aggregate. These devices exhibited an LFN form 1/<i>f</i>^&gamma; significant increase spectrum 15 dB 2 then saturated further durations. also monitored barriers. were...

Abstract We report on the reliability of In x Al 1– N/AlN/GaN‐based heterostructure field‐effect transistors (HFETs) fabricated five different wafers with varying indium compositions (0.12 ≤ 0.20) encompassing tensile/compressive strain fields. All tested devices underwent high field on‐state stress at 20 V DC drain bias and zero gate for hours. monitored current low‐frequency noise (LFN) a priori posteriori treatment to quantify device degradation. HFETs suffering tensile showed remarkably...

In an effort to investigate the particulars of their stability, In_18.5%Al_81.5%N/GaN HFETs were subjected on-state electrical stress for intervals totaling up 20 hours. The current gain cutoff frequency <i>f</i>_T showed a constant increase after each incremental stress, which was consistent with decreased gate lag and phase noise. Extraction small-signal circuit parameters demonstrated that is due decrease in gate-source capacitance (<i>C</i>_gs)...

In this work we compare electronic transport performance in HFETs based on single channel (SC) GaN/Al_0.30GaN/AlN/GaN (2nm/20nm/1nm/3.5&mu;m) and coupled (CC) GaN/Al_0.285GaN/AlN/GaN/AlN/GaN (2nm/20nm/1nm/4nm/1nm/3.5&mu;m) structures. The two structures have similar current gain cut-off frequencies (11.6 GHz for SC 14 CC ~ 1&mu;m gate length) however, the maximum drain current, I_Dmax, is nearly doubled HFET (0.64 A/mm compared to 0.36 SC). exhibit...