http://ieeexplore.ieee.org TOC Alert for Publication# 55 2013 May 16 34 5 C1 574 166 34 5 C2 C2 149 34 5 575 577 274 V_TH) variation in a multigate bulk device, quasi-planar tri-gate (QPT) bulk metal-oxide semiconductor field-effect transistors (MOSFETs) are fabricated by a 28-nm complementary metal-oxide-semiconductor (CMOS) technology. It is experimentally verified that the LER profile obtained through using the 2P2E 193-nm immersion photolithography technique has a relatively longer correlation length (i.e., lower spatial frequency) than that by the 1P1E technique, although they have a comparable root-mean-square deviation and fractal dimension. By using Monte Carlo simulations to analyze the random V_TH variations in the QPT bulk MOSFETs, we confirm that the 2P2E-LER-induced V_TH variation (versus the 1P1E-LER-induced V_TH variation) is suppressed by ~20% in terms of σ(V_TH). However, the total V_TH variation in the QPT MOSFETs is slightly improved with the 2P2E technique, because the other variation sources such as random dopant fluctuation and work-function variation have still dominated the total V_TH variation. To fully benefit from the 2P2E technique, the other random/intrinsic variations should be better controlled in the QPT CMOS technology.]]> 34 5 578 580 413 V_FB) up to temperature 75 K, possibly due to cotunneling through unintentional quantum dots. Furthermore, regular current steps are observed above V_FB, that is, each current plateau corresponds to a fully populated subband. Experimental result of transconductance peaks indicates that the subband energy spacing in the 1-D channel agrees well with theoretical prediction.]]> 34 5 581 583 396 ON/I_OFF ratio (~6×10⁸), a point subthreshold slope (SS) of ~38 mV/decade, and an average SS of ~70 mV/decade at room temperature, which indicates that JL-TFET is a promising candidate for a switching performance.]]> 34 5 584 586 704 ${rm TaN}/{rm Al}_{2}{rm O}_{3}/{rm HfO}_{2}/{rm HfAlO}_{2}/{rm SiO}_{2}/{rm Si}$ MAHOS-type nonvolatile memory devices with an epitaxial Si/Ge super-lattice (SL) channel are investigated in this letter, where the SL channel is characterized with good crystal structure and high thermal stability. Remarkable improvement on programming and erasing speeds is observed, as compared to those with SiGe channel. Furthermore, the degradation on reliability properties of retention and endurance is negligible for the device with employing a SL channel.]]> 34 5 587 589 303 E) for a long time. We found that rectifying characteristics depend on the direction of E. The forward direction coincides with the direction of E. The diode direction switches when E is inverted. The rectification factor passes from 200 to 26 from one direction to the other, the effect is reversible and can be repeated several times.]]> 34 5 590 592 542 2 and HfO₂ dielectrics with metal gate is investigated. The threshold voltage shift (ΔV_TH) at identical NBTI over-drive stress conditions is observed to be lower in ZrO₂ than in HfO₂ field-effect transistors. Ring oscillator charge pumping is applied to determine interface trap generation (ΔN_it) in the sub-1-nanometer EOT devices, with ZrO₂ devices showing about one order of magnitude lower ΔN_it than HfO₂ device. However, the ΔN_it contribution to the total ΔV_TH is very limited in sub-1-nanometer EOT devices, as the recoverable component from the pre-existing bulk defects dominates the whole NBTI degradation. Pulsed Id-Vg technique is applied to analyze the pre-existing bulk defects in those sub-1-nanometer EOT devices, and lower pre-existing bulk defect density is shown in ZrO₂, which decisively reduces NBTI in ZrO₂ gate dielectric.]]> 34 5 593 595 477 34 5 596 598 1535 2H₄)-based nitridation process, which reduces the native oxide (GeO_x) component and finally transforms it into GeO_xN_y on intrinsic Ge, to relieve the E_F pinning problem. The decomposition of GeO_x and formation of GeO_xN_y by N₂H₄ are systematically investigated through cross-sectional transmission electron microscopy, X-ray photoelectron spectroscopy, and atomic force microscopy analyses. After performing the N₂H₄-based nitridation process for 12 h, high Φ_H (~0.59 eV) and therefore high ON/OFF current ratio (~10⁴) are achieved for Ti/Ge Schottky junction diode.]]> 34 5 599 601 508 34 5 602 604 385 V_TH) of p-GaN gate high-electron-mobility transistors (HEMTs) is presented. The hole depletion width in the p-GaN layer at the gate interface is one of the key controlling factors of V_TH in p-GaN gate HEMTs. In order to increase the depletion width, we devise a new device structure of p-GaN gate HEMT having a source-connected p-GaN bridge. We demonstrate that a bridged p-GaN gate HEMT structure increases the V_TH from 0.93 to 2.44 V.]]> 34 5 605 607 499 L_ch) down to 20 nm are fabricated by integrating a higher k LaAlO₃-based gate-stack with an equivalent oxide thickness of 1.2 nm. It is found that inserting an ultrathin (0.5 nm) Al₂O₃ interfacial layer between the higher k LaAlO₃ and InGaAs can significantly improve the interface quality and reduce device variation. As a result, a record low subthreshold swing of 63 mV/dec is demonstrated at sub-80-nm L_ch for the first time, making InGaAs GAA nanowire devices a strong candidate for future low-power transistors.]]> 34 5 608 610 1141 $mu{rm m}$ diameter exhibit a 3-dB modulation bandwidth of 225.4 MHz and a light output power of 1.6 mW at the current of 35 mA. Such LEDs can be applied to visible light communication in future.]]> 34 5 611 613 467 V_DIST) on the depth of the reset level during switching. Our slow voltage ramp read disturb tests at different reset levels indicate the possibility of filamentary instability even for read voltages lower than the standard value of 0.10 V. These experimental trends can be well explained using the quantum point contact model for conduction in the filament, as deeper reset levels induce very steep potential gradients at the two ends of the constriction that make the filaments highly unstable and susceptible to structural modifications due to vacancy generation and/or transport during memory read operation.]]> 34 5 614 616 558 2 thin film as the insulator of resistive random access memory (RRAM) by supercritical carbon dioxide (SCCO)₂ fluid treatment. After treatment, low resistance state split in to two states, we find the insert RRAM, which means it has an operating polarity opposite from normal RRAM. The difference of the insert RRAM is owing to the resistive switching dominated by hydrogen ions, dissociated from OH bond, which was not by oxygen ions as usual. The current conduction mechanism of insert RRAM was hopping conduction due to the metal titanium reduction reaction through SCCO₂.]]> 34 5 617 619 553 34 5 620 622 329 $(V_{rm RESET})$ and the RESET current $(I_{rm RESET})$ of ${rm Pt}/{rm HfO}_{2}/{rm Pt}$ resistive random access memory (RRAM) devices operated under unipolar mode are analyzed. The experimental results show that both the distributions of $I_{rm RESET}$ and $V_{rm RESET}$ are strongly influenced by the distribution of initial resistance in the ON state $(R_{rm ON})$, which is related to the size of the conductive filament (CF) before RESET. By screening the statistical data into different resistance ranges, both the distributions of $I_{rm RESET}$ and $V_{rm RESET}$ are shown to be compatible with a Weibull model. Contrary to previous reports for NiO-based RRAM, the Weibull slopes of the $I_{rm RESET}$ and $V_{rm RESET}$ are demonstrated to be independent of $R_{rm ON}$. This is an indication that the RESET point, defined in this letter as the point of maximum current, corresponds to the initial phase of CF dissolution. On the other hand, given that the scale factor of the $V_{rm RESET}$ distribution $(V_{rm RESET63%})$ is roughly independent of $R_{rm ON}$, the scale factor of the $I_{rm RESET}$ $(I_{rm RESET63%})$ is inversely proportional to $R_{rm ON}$. This is analogous to what was found in NiO-based RRAM and it is consistent with the thermal dissolution model of RESET. Our results highlight the intrinsic link between the SET and RESET statistics and the need for controlling the variation of ON-state resistance to reduce the variability of the RESET voltage and current.]]> 34 5 623 625 601 4 and 10⁶ pulse cycles is compared to the uncycled LRS retention, based on the (40 × 40 nm)- HfO₂/Hf bipolar RRAM devices in a 1T1R configuration. The LRS retention after 10⁴ pulse cycles does not show degradation, while a larger failure bit tail is seen after 10⁶ pulse cycles. The larger failure bit tail is found strongly related to the degradation of the cycled LRS state. From the LRS current fitting with a quantum point contact model, it is found that the total number of oxygen vacancies (V_ox) in the filament decreases after 10⁶ cycles, leaving a narrower switching constriction. The narrower switching constriction therefore suffers more from the self-diffusion of the (V_ox)'s from the filament into HfO₂ bulk, and results in degradation of the LRS retention.]]> 34 5 626 628 695 34 5 629 631 286 34 5 632 634 263 2O molecules in the back channel protective layer. We conclude that the H₂O molecules and the quality of passivation layer affect the degradation behavior of α-IGZO TFT devices.]]> 34 5 635 637 696 34 5 638 640 403 S) and the subgap density-of-states [DOS: g(E)] over the bandgap in amorphous semiconductor thin film transistors (TFTs). It is fully based on the experimental gate bias-dependent coupling factor [m(V_GS)] under subthreshold bias. Through the proposed technique only with current-voltage data under subthreshold operation, a unified extraction of the DOS with a consistent mapping of the gate bias (V_GS) to the subgap energy is obtained. Applying to amorphous InGaZnO TFTs, g(E) is obtained to be a superposition of two exponential functions with N_TA = 1.62 × 10¹⁷ eV^-1 cm^-3 and kT_TA = 0.026 eV for the tail states while N_DA = 6.5 × 10¹⁶ eV^-1 cm^-3 and kT_DA = 0.22 eV for the deep states.]]> 34 5 641 643 495 34 5 644 646 530 2O) thin-film transistors (TFTs). Transfer curves measured before and after the application of constant gate bias stress under air and vacuum environments show that the partial pressure of the oxygen in the environment does not much affect the transfer characteristics and bias-stress-induced instabilities of the Cu₂O TFTs. During the negative gate bias stresses, the transfer curves shift to the negative direction without a significant variation of the shape, which is attributed to the hole trapping in the interface or bulk dielectric layers with a negligible creation of additional interface trap states. During the positive gate bias stresses, a threshold voltage hardly moves to the positive direction because of the lack of free electron inside the p-type Cu₂O, but a notable degradation of the subthreshold slope is observed. From the recovery characteristics, the generated traps during the positive gate bias stress are estimated to be metastable ones in p-type Cu₂O TFTs.]]> 34 5 647 649 521 60) as an electron transport layer and tris (8-hydroxyquinolinato)-aluminum (Alq₃) as a buffer layer are successfully fabricated. For the optimal device with structures of ITO/NPB (40 nm)/Alq₃ /(30 nm)/C₆₀ (20 nm)/Alq₃ (3 nm)/LiF (0.8 nm)/Al (120 nm), the turn-on driving voltage is 2.8 V, which is reduced 0.4 V compared with that of the control device. Meanwhile, the driving voltage of 4.9 V has been achieved at a luminance of 1000 cd/m² in this device, which is reduced 1.8 V compared with that of the control device. The results have a significant effect on the commercialization application of the devices.]]> 34 5 650 652 472 5 Ω is observed in a 1-μm-thick resistor.]]> 34 5 653 655 541 2 and an efficiency of 4.2 cd/A. The efficient energy transfer and performance of the QDs/PVK hybrid EML are highly depended on the doping concentration of the QDs.]]> 34 5 656 658 438 34 5 659 661 364 11 Jones and 1.42 × 10¹² Jones under 1 and 2-V reverse bias, respectively, that are close to conventional InGaAs short wave infrared detectors.]]> 34 5 662 664 423 4 plasma treatment on low-temperature oxides to enhance the open-circuit voltage of the solar cells. Low-temperature oxides grown by a nitric acid solution are treated with the CF₄ plasma. Solar cells undergoing this scheme show an improved performance, including low-saturation current density and good quantum efficiency at short wavelengths. Experimental results demonstrate that the CF₄ plasma pretreatment on low-temperature oxides can significantly improve the open-circuit voltage, short-circuit current, and fill factor for silicon wafer-based solar cells. This technique is very promising for in-line solar cell manufacturing.]]> 34 5 665 667 396 34 5 668 670 582 34 5 671 673 648 $mu{rm m}$ 5-V CMOS process. Through inserting one additional parasitic bipolar junction transistor into SCR device structure, this new proposed SCR can increase the holding voltage without causing degradation on its ESD robustness.]]> 34 5 674 676 329 x/C:SiOx) resistive switching memory device with a high on/off resistance ratio and small working current (0.02 mA), is presented. Through the analysis of Raman and Fourier transform infrared spectroscopy spectra, we find that graphene oxide exists in the C:SiOx layer. It can be observed that Zr:SiOx/C:SiOx structure has superior switching performance and higher stability compared with the single-active-layer (Zr:SiOx) structure, which is attributed to the existence of graphene oxide flakes formed during the sputter process. I-V characteristics under a series of increasing temperature were analyzed to testify the carrier hopping distance variation, which is further verified by our graphene oxide redox reaction model.]]> 34 5 677 679 457 x are due to a higher density of the as-grown oxygen vacancy defects assisting the charge transport. Reduction of the dielectric BD field (E_BD) in HfO_x is explained by the lower zero-field activation energy (E_A,G) of the defect generation process, as extracted from time-dependent dielectric BD experiments.]]> 34 5 680 682 928 34 5 683 685 328 34 5 686 688 763 34 5 689 691 209 Q fused-quartz micromechanical resonators is demonstrated. Plasma-assisted quartz-on-quartz direct bonding at a low temperature in combination with quartz deep-reactive ion etching technique enables a simple wafer-level fabrication of self-mounted, electrostatically driven fused-quartz resonators. A 27-kHz capacitively transduced double-ended tuning fork fused-quartz resonator oscillator is successfully fabricated using the developed process. A high resonator Q-factor of 68000 is obtained, and the constructed oscillator shows a signal-to-noise ratio of 70 dB.]]> 34 5 692 694 499 34 5 695 697 717 2 are obtained, whereas in the integrated grid device, a transparency of 75% and a maximum current density of 74 mA/cm² are obtained. The high transparency achieved makes the two cathodes attractive for low power consumption vacuum tubes.]]> 34 5 698 700 815 2O₃ nanowires (NWs) on cost-effective SiO₂/Si template and the fabrication of β-Ga₂O₃ NW field emitters. It is found that the β-Ga₂O₃ NWs grown at 950^°C are structurally uniform, defect free, and well-oriented with pure monoclinic structure. It is also found that turnon fields are 2.0, 3.9, and 5.8 V/μm whereas field-enhancement factors β are 1890, 2760, and 4489, for the samples grown at 850^°C, 900 ^°C, and 950^°C, respectively. For the sample prepared at 950^°C, it is found that we could further reduce the turnon field from 2 to 1.2 V/μm whereas enhance the field-enhancement factor β from 4489 to 6926 by ultraviolet irradiation.]]> 34 5 701 703 741 34 5 704 706 1114 $5times 10^{12}~{rm cm}^{-2}$ at room temperature.]]> 34 5 707 709 900 34 5 710 711 1138 34 5 712 712 111 34 5 713 713 308 34 5 714 714 233 34 5 715 C3 166 34 5 C4 C4 5