Low-threshold, highly reliable 630 nm-band AlGaIP visible laserdiodes with AlInP buried waveguide

Low-threshold, highly reliable 630 nm-band AlGaInP visible laser diodes have been developed by employing a low-loss optical waveguide buried in the AlInP layer. A low-threshold current of 19 mA at 25°C is obtained with a cavity length of 310 μm. This current is the lowest value for 630 nm-band AlGaInP visible laser diodes, to our knowledge. Our AlInP-buried laser diodes with a cavity length of 500 μm operated over 7000 h without significant degradation at 60°C and 5 mW     

Numerical study on performance of disk MHD generator using frozen inert gas plasma

In an magnetohydrodynamic (MHD) generator using a frozen inert gas plasma (FIP), the availability of a frozen argon plasma, the influence of plasma uniformity at the generator inlet on the performance, and the feasibility of a large-scale generator are numerically examined by /spl gamma/-/spl theta/ two-dimensional simulation. The FIP is produced by pre-ionizing inert gas without an alkali metal seed at the generator inlet, then the ionization degree of the plasma is kept almost constant in the whole of the channel because of considerable slow recombination of the inert gas just like frozen reaction plasma. It is found that not only helium, but also argon frozen plasma MHD generation is realized, although highly accurate control of inlet ionization degree is necessary for argon. It is important to reduce the nonuniformity of plasma properties at the generator inlet in order to raise the maximum enthalpy extraction ratio. Even for the large-scale generator with 1000-MW thermal input, the ionization degree is kept almost constant in the whole of the channel and the high performance is obtainable. This result is extremely attractive for the FIP MHD generator.     

Decomposition mechanism of triethylindium (TEI) on a GaP(0 0 1)-(2×1) surface studied by LEED, AES, TPD and HREELS

Adsorption and decomposition of triethylindium (TEI: (C₂H₅)₃In) on a GaP(0 0 1)-(2×1) surface have been studied by low-energy electron diffraction (LEED), Auger electron spectroscopy (AES), temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS). It is found from the TPD result that ethyl radical and ethylene are evolved at about 300–400 and 450–550 K, respectively, as decomposition products of TEI on the surface. This result is quite different from that on the GaP(0 0 1)-(2×4) surface. The activation energy of desorption of ethyl radical is estimated to be about 93 kJ/mol. It is suggested that TEI is adsorbed molecularly on the surface at 100 K and that some of TEI molecules are dissociated into C₂H₅ to form P–C₂H₅ bonds at 300 K. The vibration modes related to ethyl group are decreased in intensity at about 300–400 and 450–550 K, which is consistent with the TPD result. The TEI molecules (including mono- and di-ethylindium) are not evolved from the surface. Based on the TPD and HREELS results, the decomposition mechanism of TEI on the GaP(0 0 1)-(2×1) surface is discussed and compared with that on the (2×4) surface.     

A perfect one-factorization ofK 36

In this paper, a perfect one-factorization ofK ₃₆ is given, which is factor-1-rotational.     

Scalar curvature of spheres

Financial support from the FRD is gratefully acknowledged     

Self-healing algorithm for logical mesh connection on ring networks

A self-healing algorithm is proposed for a ring network connected as a logical mesh. It offers good performance in terms of protection line capacity, restoration time, and survivability against multiple failures     

On the possibility of a radical decrease in the strength of many-body interactions in the organic metal α-(BETS)<Subscript>2</Subscript> KHg(SCN)<Subscript>4</Subscript>

Behavior of the de Haas-van Alphen (dHvA) oscillations depending on the angle between the magnetic field direction and the perpendicular to conducting layers in the quasi-two-dimensional organic metal α-(BETS)₂ KHg(SCN)₄ was studied in detail. The angular dependence of the dHvA oscillation amplitude exhibits a series of minima (at ±43.2°, ±64.6°, and ±72.0°) related to the “zero spin” effect, through which it is possible to estimate the splitting factor. An analysis of this value suggests that many-body interactions in the compound studied are either absent or at least radically weakened.     

A semi-static complementary gain cell technology for sub-1 V supplyDRAM's

A new semi-static complementary gain cell for future low power DRAM's has been proposed and experimentally demonstrated. This gain cell consists of a write-transistor and its opposite conduction type read-transistor with a heating gate as a storage node which causes a shift in the threshold voltage. This gain cell provides a two orders of magnitude larger cell signal output and higher immunity to noise on the bitlines when compared with a conventional one-transistor DRAM cell without increasing the storage capacitance even at a supply voltage of 0.8 V. The 0.87 μm² cell size is achieved by using a 0.25 μm design rule with a polysilicon thin-film transistor built in the trench and phase shifted i-line lithography     

Metallized ultra-shallow-junction device technology for sub-0.1μm gate MOSFET's

This paper describes a new ultra-thin SOI-CMOS structure offering reduced parasitic diffusion-layer resistance. It addresses ways to deal with the ultra-shallow junctions required by sub-0.1 μm MOSFET's. Based on a CVD tungsten process we experimentally investigate the characteristics of selectively grown tungsten used in the source and drain region made in SOI layers of various thicknesses ranging from 10 to 100 nm. We also investigate certain CMOS device characteristics. The SOI-CMOS structure, with low parasitic diffusion-layer resistance and good contact characteristics for ultra-shallow junction devices exhibits superior device performance and high scalability