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The downscaling of the capacitance equivalent oxide thickness (CET) of a gate dielectric film with a high dielectric constant, such as atomic layer deposited (ALD) HfO2, is a fundamental challenge in achieving high-performance graphene-based transistors with a low gate leakage current. Here, we assess the application of various surface modification methods on monolayer graphene sheets grown by chemical vapour deposition to obtain a uniform and pinhole-free ALD HfO2 film with a substantially small CET at a wafer scale. The effects of various surface modifications, such as N-methyl-2-pyrrolidone treatment and introduction of sputtered ZnO and e-beam-evaporated Hf seed layers on monolayer graphene, and the subsequent HfO2 film formation under identical ALD process parameters were systematically evaluated. The nucleation layer provided by the Hf seed layer (which transforms to the HfO2 layer during ALD) resulted in the uniform and conformal deposition of the HfO2 film without damaging the graphene, which is suitable for downscaling the CET. After verifying the feasibility of scaling down the HfO2 thickness to achieve a CET of ~1.5 nm from an array of top-gated metal-oxide-graphene field-effect transistors, we fabricated graphene heterojunction tunnelling transistors with a record-low subthreshold swing value of <60 mV/dec on an 8″ glass wafer.

Nanometer scale Ge2Sb2Te5 (GST) domains formed by immiscible mixture of GST-SiOx at room temperature and 180 °C show remarkable suppression in electrical and thermal conductivity. Thermal boundary resistance with increased GST-SiOx interface becomes crucial to the reduction in thermal conductivity. These conductivity reductions concurrently result in the reduction in programming current and power consumption in phase change memory devices.

Laryngospasm, an occlusion of the glottis, can occur at any time during anesthesia, and is associated with serious perioperative complications such as hypoxia, hypercabia, aspiration, bronchospasm, arrhythmia, prolonged recovery, cardiac collapse, and eventually catastrophic death. Importantly, postoperative negative pressure pulmonary edema (NPPE) is a rare, but well described life-threatening complication related to acute and chronic upper airway obstruction. Sugammadex well known for affirmatively reducing the postoperative pulmonary complications associated with residual neuromuscular blockade may have an indirect role in triggering the negative intrathoracic pressure by raising a rapid and efficacious respiratory muscle strength in acute upper airway obstruction. Herein, we report a case of postoperative NPPE following repetitive laryngospasm even after reversal of rocuronium-induced neuromuscular blockade using sugammadex.

We introduce a reliable and robust gate dielectric material with tunable dielectric constants based on a mesostructured HfxAlyO2 film. The ultrathin mesostructured HfxAlyO2 film is deposited on graphene via a physisorbed-precursor-assisted atomic layer deposition process and consists of an intermediate state with small crystallized parts in an amorphous matrix. Crystal phase engineering using Al dopant is employed to achieve HfO2 phase transitions, which produce the crystallized part of the mesostructured HfxAlyO2 film. The effects of various Al doping concentrations are examined, and an enhanced dielectric constant of ∼25 is obtained. Further, the leakage current is suppressed (∼10(-8) A/cm(2)) and the dielectric breakdown properties are enhanced (breakdown field: ∼7 MV/cm) by the partially remaining amorphous matrix. We believe that this contribution is theoretically and practically relevant because excellent gate dielectric performance is obtained. In addition, an array of top-gated metal-insulator-graphene field-effect transistors is fabricated on a 6 in. wafer, yielding a capacitance equivalent oxide thickness of less than 1 nm (0.78 nm). This low capacitance equivalent oxide thickness has important implications for the incorporation of graphene into high-performance silicon-based nanoelectronics.

Articles you may be interested inMultiple beam sub-80 -nm lithography with miniature electron beam column arraysThe authors demonstrated successful nanopatterning using a high resolution lattice image obtained by transmission electron microscopy ͑TEM͒ as a mask signal ͓H. S. Lee et al., Adv. Mater. ͑Weinheim, Ger.͒ 19, 4198 ͑2007͔͒. In this process, the quality of the patterning result is critically dependent on the lattice image, which, in turn, is critically dependent on the quality of the mask. It is often noted that the quality of the mask prepared by the conventional TEM sample preparation technique is far from perfect, which critically limits the quality of patterning. In this work, they first discuss the various origins of the noise signal generated by the mask and then introduce a special type of objective aperture ͑noise reduction aperture͒ to remove the noise signal. The effect of the noise reduction aperture, designed for the Si ͓110͔ zone axis, is experimentally demonstrated.

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