No abstract

The reaction of silicon nitride films on silicon substrates in sub- and supercritical water at temperatures between 100 and 400 °C has been studied for the first time. The etching rates for the silicon nitride films were higher than those for silicon dioxide films under the same conditions. A novel selective etching method for silicon nitride films using subcritical water has been proposed. The etching mechanism for silicon nitride films in subcritical water was studied by means of infrared spectroscopy and ion chromatography. The etching selectivity at 200 °C and 10 MPa reached 70. An etching rate of 7.5 nm/min for the silicon nitride films was obtained under the same conditions. The selectivity value was higher than that of the conventional method using phosphoric acid, while the etching rate was comparable. Moreover, water is nontoxic; therefore, the proposed method is environmentally friendly. The proposed selective etching method for silicon nitride films using subcritical water is one of the promising candidates for future etching technologies.

We observed electrical switching phenomena in a phase change material (Ge 2 Sb 2 Te 5 ) in contact with metallic nanowires of 100 nmφ, which were embedded in a track-etched polycarbonate membrane by electroplating. While the electrical resistance of the system did not change when applied voltage was 0-1 V, switching occurred from a high-resistance state (HS) to a low-resistance state (LS) when voltage was increased from 0 V to 5 V and then decreased to 0 V. The maximum current was 100 nA. LS was 10 times more conductive than HS. A reset operation from LS to HS was realized using a 20 ns pulse of 5 V. Switchings from HS to LS and from LS to HS were confirmed several times, demonstrating that the device is rewriteable.

We have developed a full color flexible top‐emission AMOLED display with 80 ppi resolution using In‐Ga‐Zn‐O TFT backplane on PEN foil under the maximum process temperature of 150 oC. Notwithstanding the low processing temperature, the TFTs with SiOx passivation layer show high reliability with VTH shift of less than 0.2 V at 10,000 seconds under bias‐stress of −10 V.

A novel fabrication method of silicon quantum wire gate-all-around transistor (GAAT), in which the gate oxide and the gate electrode are wrapped around ultrafine silicon quantum wire, has been proposed. In order to verify one-dimensional (1D) subband effects, we have studied quantum transport in Si quantum wire GAAT with a width of 50 nm at 1.5 K in zero-magnetic field and in fields up to 10 T. Electrical population and magnetic depopulation of 1D subbands are clearly observed.