Transconductance (gm) enhancement in n-type and p-type nanowire field-effect-transistors (nwFETs) is demonstrated by introducing controlled tensile strain into channel regions by pattern dependent oxidation (PADOX). Values of gm are enhanced relative to control devices by a factor of 1.5 in p-nwFETs and 3.0 in n-nwFETs. Strain distributions calculated by a three-dimensional molecular dynamics simulation reveal predominantly horizontal tensile stress in the nwFET channels. The Raman lines in the strain controlled devices display an increase in the full width at half maximum and a shift to lower wavenumber, confirming that gm enhancement is due to tensile stress introduced by the PADOX approach.

The authors report the enhancement of transconductance in nanowire field effect transistors due to build-up tensile stress during thermal oxidation. To evaluate the effect of stress, nanowires were thermally oxidized at (A) 900°C∕15min, (B) 850°C∕1h, and (C) 850°C∕1h with a subsequent 1000°C annealing. The transconductance of sample B is enhanced 2.6 times compared to sample A. No enhancement of transconductance is observed in sample C. The Raman spectra indicate tensile stress in sample B and compressive stress in sample C. This establishes that gm enhancement is due to the build-up tensile stress in nanowires, but is diminished by viscoelastic relaxation.

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Two partially coherent light laser beams, coupled with a random phase plate were focused at an angle of 31.7°with the centers of the beams offset by 250 m. This produced a relatively uniform ͑7% root-mean-square͒ irradiated spot of 400 m. When this technique was used to produce a shock wave in a copper wedge, a relatively uniform shock of 2 ns duration was produced. In addition, a multilayered flyer plate was accelerated using this method to an average speed of 21 km/s and produced a planar impact on a glass window. It is anticipated that this technique can be used to produce important multi-Mbar equation of state information in future experiments.

Transient lattice expansion of a Si(111) crystal induced by pulsed laser heating is studied by the picosecond pulsed X-ray diffraction. The X-rays used are laser induced X-rays with a pulse duration of 6 ps. The lattice expansion at 3 ns after laser heating is estimated to be about 1×10-3 Å from the observed shift of Bragg angles, which is in good agreement with the numerical calculations of the temperature distribution and the heat transport analysis.