Two-terminal mono-and multilayer graphene nanoribbon resistive random access memories (ReRAMs) are experimentally demonstrated. Fundamental ReRAM properties, device scalability, and width dependence with device scaling are investigated. The lower switching energy is obtained for smaller channel width, indicating the suitability of graphene nanoribbons for high-density LSIs. Operation mechanism is studied by changing the type of contact metal and the number of graphene layers as well as by performing physical analysis by atomic force microscopy (AFM), cross-sectional transmission electron microscopy (TEM), and electron energy-loss spectroscopy (EELS). Then, it is suggested that the mechanism is the chemical bonding-state change of graphene. #

Enhancement‐mode GaN metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) have been reported. We utilized the atomic layer deposition (ALD) method for the fabrication process of the gate dielectric, in order to suppress plasma damage and obtain high‐quality dielectric film. In the fabricated devices, the specific on‐state resistance of 3.2 mΩcm2 and the breakdown voltage of 800 V were achieved. Moreover, a 10‐year lifetime with a cumulative failure rate of 0.1% was guaranteed at over 20 V. This voltage was twice the operation voltage of 10 V. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

In this work, a thermal treatment technique under NH3 ambient for the recess surface of GaN‐MOSFETs is developed. Immediately following the fabrication process of the recess, the bottoms of these structures have rough surfaces and step‐terrace structures cannot be observed because of the plasma‐induced damage. However, clear step‐terrace structures are formed by the thermal treatment, and the RMS values of the surface roughness decrease from 0.26 to 0.14 nm, which is comparable to those of the as‐grown epitaxial film. In addition, it is confirmed that concentrations of impurity atoms introduced during the recess fabrication process are decreased by the thermal treatment. The channel mobility of the GaN‐MOSFETs without the thermal treatment is 118 cm2 Vs−1, whereas that of the device whose fabrication process includes the thermal treatment increased to 149 cm2 Vs−1. These results indicate that the thermal treatment under NH3 ambient is effective for reducing on‐state resistance of GaN‐MOSFETs.

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