Configuration of the wetting system. Droplets of pure Sn and Sn-10Cu, Sn-20Cu, and Sn-30Cu (wt%) were considered, respectively. Each droplet comprises 3000 atoms of Sn (red) and Cu (blue). Bottom of the substrate comprises two layers of rigid Cu atom. The origin of the coordinates is on the substrate surface. The center of the droplet was positioned on z axis and the bottom of the droplet was positioned about 3Å above the Cu surface when the system has been in equilibration.
Phase diagram of nanometer-scale Sn-Cu alloys. The range of weight fraction of Cu in the alloy considered in this diagram is between 0.0 and 0.6. The lower (upper) curve represents the solidus (liquidus) temperature as a function of the weight fraction of Cu.
Cross-section snapshots from simulations when the wettings by the pure Sn droplet at 1000K have taken place for 300 ps on (a) Cu(100); (b) Cu(110); and (c) Cu(111) planes, respectively. Surface alloying is observed through the interchange of Sn (red) and Cu(blue) atoms across the substrate surface.
Variations of radius of the spreading film, R(t), for the Sn droplets wetting on Cu(100) (solid curves), Cu(110) (long dashed curves), and Cu(111) (short dashed curves) at 800K (red curves) and 1000K (black curves), respectively.
Density profiles for Cu(black) and Sn(blue) as functions of z at 300 ps in the wettings by liquid Sn on (a) Cu(100); (b) Cu(110); and (c) Cu(111) planes performed at 1000K, respectively.
Diagrammatic depiction for determining position of the theoretical liquid/solid interface, zint, and the weight fraction of Cu at that position, WCu(zint). First establish the curve-fitting density function ρCu(z), using data of the density peak for Cu in the inter-diffusion zone, and then determine the position of the interface by letting d2ρCu(z)/dz2=0. Finally, compute the corresponding weight fraction of Cu, using data of density peak for Cu in the inter-diffusion zone, and determine the weight fraction of Cu at the interface by linearly interpolating the values at the neighboring points that the interface is in between. The inset shows the variation of zint with time for the Sn wetting on Cu(100) at 1000K, for a depiction example.
Cross-section snapshots at 300 ps showing color scaled distributions of weight fraction of Cu on planes perpendicular to z axis for the wettings of Cu(100) at 1000K. The planes considered here are at (a) z2=1.965Å; (b) z1=0.621Å; (c) z-1=-2.103Å; and (d) z-2=-4.051Å, respectively. Inside the broken circle in each diagram is the area over which the densities of Cu and Sn are averaged.
Variations of radius, R(t), for the spreading films of Sn (solid curves), Sn-10Cu (long dashed curves), Sn-20Cu (short dashed curves), and Sn-30Cu (dotted curves) on Cu(100) (black curves) and Cu(110) (red curves), respectively. Presented here are the results from the wettings performed at 1000K. The influence of the droplet’s alloy composition at other temperatures is similar to what is shown here.
Scheme that demonstrates how the indentation depth of the composite film under uniform pressures is related to the internal stress and contact stress c.
Surface image of the Al (50 nm)/a-Si (200 nm)/Glass 7740 specimen at room temperature (25℃). (b) Morphology of the Si layer after etching of the Al layer at an annealing temperature of 350℃.
Bright field HR-TEM micrographs of (a) the cross-section after indentation, (b) the local magnification of the indentation cavity and the diffraction pattern of point A, (c) the diffraction pattern of point B, and (d) the diffraction pattern of point C and point D.
(a) Relationship of the contact stress c and the strain c for the a-Si/μc-Si film annealed at a temperature of 350℃. (b) Gibbs free energy for the diamond-Si, -tin Si, ph-Si, and HDA phases. (c) Raman spectra on the area of μc-Si at an annealing temperature of 350℃ before and after indentation. (d) Experimentally obtained the σc_1, σc_2, and σc_3 curves (dashed) predicted by the proposed model.
The cross-sectional view and coordinates of the silicon nanowire on insulator transistor used in this study. Here gate length Lg = 10 nm and Lex = 20 nm. For Poisson solver, tox-ex = tox-sub = 5 nm.
The simulated current-voltage characteristics for six different values of source-drain underlap. The drain bias is fixed to 0.5 V.
Conduction band and valence band profiles superimposed on the energy distribution of current for two different values of underlap, 0 nm and 5 nm, at (a) VGS = 0 V and (b) VGS = 0.5 V. The source Fermi level is at 0 eV and the drain Fermi level is at -0.5 eV.
The (a) off current, (b) on current, (c) on/off current ratio, and (d) inverse subthreshold slope versus underlap plots.
The current-voltage characteristics of 5 nm gate length devices with two different values of underlap.
The (a) gate capacitance and (b) the percentage contribution of its different components versus gate bias. The meanings of Cb, Cs, and Cd are described in the text. The drain bias is fixed to 0.5 V and the underlap value Lu = 0 nm.
The (a) gate capacitance and its different components, (b) trans- conductance, (c) intrinsic switching delay, and (d) intrinsic cut-off frequency versus underlap. The meanings of Cb, Cs, and Cd are described in the text.
SEM image of Ni nanowires synthesized via hydrazine hydrate: (a) low magnification image; (b) high magnification image.
(a) TEM image of Ni nanowires. (b) The selected-area electron diffraction (SAED) pattern taken on an individual Ni nanowire.
SEM image of Ni nanoparticles: (a) low-magnification; (b) magnified image.
Schematic illustration of growth mechanism and SEM images of Ni nanowires taken at three steps during the reaction process: (I) after the first 10 min; (II) after the second 10 min; and (III) after the third 10 min. The scale bars in all the insets represent 200 nm.
Nano-Micro Letters, June 2010, Volume 2, Issue 2, pp 126-133
Publication Date (Web): 06 July 2010 (Article)
Device cross sections used for simulation. (a) zero-Schottky-barrier source-drain contacts. (b) doped source-drain contacts.
The band gap variations with (a) uniaxial and (b) torsional strains of (13,0) and (14,0) CNTs. Here, compressive and tensile uniaxial strains are represented as negative and positive strains, respectively.
The off-state current versus strain. The SB means zero-Schottky-barrier and DP means doped source-drain contacts.
Conduction band profiles vs channel position in (a) off (VDS = 0.5 V and VGS = 0.0 V) state and (b) on (VDS = 0.5 V and VGS = 0.5 V) state. Here, SB means zero-Schottky-barrier, and DP means doped source-drain contacts devices. The channel is a (13,0) CNT. The solid lines are the band profiles of unstrained CNT channel, and the dashed lines are the band profiles of 2% tensile strained CNT channel.
The on-state current versus strain. Here, SB means zero-Schottky-barrier contact and DP means doped contact.
The on/off current ratio versus strain. Here, SB means zero-Schottky- barrier contact and DP means doped contact.
The inverse subthreshold slope versus strain. Here, SB means zero- Schottky-barrier contact and DP means doped contact.
The on-state transconductance versus strain. Here, SB means zero- Schottky-barrier contact and DP means doped contact.
The on-state intrinsic switching delay and on-state intrinsic cut-off frequency versus strain for zero-Schottky-barrier CNTFETs.
The on-state intrinsic switching delay and on-state intrinsic cut-off frequency versus strain for doped contact CNTFETs.
Schematic diagram of carbon nanocone showing Cartesian coordinate system and a uniform electric field, E, applied at an incidence angle, E, to the cone axis ( -axis).
Electric-field-dependent low-energy states of carbon nanocones for E °: (a). N1080, °, (b). N1060, °, (c). N1050, °, (d). N1056, °, (e). N1022, °, where N is the total number of carbon atoms in the nanocone and is the disclination angle. (f). Electric-field-dependent Fermi energies corresponding to five systems shown in (a) to (e).
(a). Influence of E=E|| on electric-field-dependent energy gaps of carbon nanocones with disclination angle of °, °, 180°, 240° and 300°, respectively. (b). Influence of electric-field incidence angle on the energy gap of the carbon nanocones with ° and N1080.
Influence of nanocone height (L=6~48Å) on energy gap of the carbon nanocone with ° and N1056 for E=0 0/Å and E=0.01 0/Å which applied with the incidence angles of 0°, 30°, 60° and 90°, respectively.
Schematic diagram for the fabrication of multi-level 3-D microstructures by the phase inversion process: (i) Construct the first layer of micro structures with embedded structures on the substrates by the routine UV-LIGA process; (ii) Fill the filler into the 1st layer micro structures; (iii) Spin coating the 2nd SU-8 layer for the 2nd level microstructure; (iv) Construct the 2nd level SU-8 microstructure by the routine UV-LIGA process; (v) Fill the filler into the 2 level micro structures; (vi) Spin coating the 3rd SU-8 layer for the 3rd level microstructure; (vii) Fabricate the 3rd level SU-8 micro structure by routine UV-LIGA process and fill the filler in to the 3rd level micro structures; (viii) Fabricate several level microstructures by repeating (ii)-(iv) to form desired levels of microstructures; (ix) Spin coating the last SU-8 layer for sealing; (x) Seal the multi-level microstructures by solidification of the SU-8 layer after exposure under UV-light.
Connected two-layer 3-dimensional microchannels. (a) The flat optical image of one cross-connected two-layered 3-D microchannels; (b) The optical images of the cross-section for the connected two-layer 3-D microchannels; (c) The SEM image on the cross-section and two channels at the 2nd layer; (d) The SEM image with two-layered one channel at the bottom layer and one channel at the top layer.
Typical examples of microstructures with connecting parts. (a) The SEM image of one big reservoir with one U-shape channels in the bottom; (b) The SEM image of one big reservoir connecting with two top channels; (c) The optical image of the big reservoir connecting with two top channels clearly showing the opening parts of the two channels on the top of the reservoir.
One typical sealed shallow microchannel with height of 40 μm and width of 350 μm. (a) The optical image of one shallow microchannel; (b) The SEM image of the cross-section of this shallow microchannel (dashed square in (a)).