摘要:

We propose a silicon Fabry–Perot planar waveguide modulator structure consisting of two Bragg reflectors to form the cavity. The Bragg reflectors are nanoscale trenches in the waveguide fabricated using electron beam lithography and reactive ion etching. Compared to conventional waveguide modulator designs, large modulation depth can be achieved with much smaller modulator length using high‐finesse Fabry–Perot cavity, leading to much less loss and higher speed. This modulator design can also be utilized as an externally tunable spectral filter. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116449

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A new mechanism of laser plasma generation of current along an irradiated conductive target, and a considerable (more than 1000 times) enhancement of magnetic field outside the plasma has been found. This mechanism is realized in experimental configurations with spatial asymmetries of target dimension scale. Such asymmetries with the largest possible scale was found to be the main factor that determines electromagnetic phenomena detected by external probes outside the laser plasma. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116450

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Expitaxially oriented growth of diamond film on Si(001) was achieved using hot filament chemical vapor deposition. The epitaxial relationship between the film and the substrate was confirmed by the observation through scanning electron microscopy and high‐resolution transmission electron microscopy (HRTEM) as follows: Dia(001)//Si(001) and Dia⟨110⟩//Si⟨110⟩ with a misorientation angle of 9° between Dia(001) and Si(001). This reports the HRTEM observation of the largest area of the diamond/Si interface (larger than 880 A˚). It demonstrates that the intermediate &bgr;‐SiC layer is unnecessary for achieving diamond epitaxy on Si. Discussion reveals that the value of the misorientation angle between Dia(001) and Si(001) is not unique and should be controlled to deposit single‐crystal diamond films on Si. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116451

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Plasma‐deposited carbon‐based polymer films are examined for use as an all‐dry positive‐tone photoresist for 193 nm lithography. These films are designed to crosslink upon exposure to 193 nm radiation, enabling selective silicon uptake via reaction of silylamine gas with hydroxyl in the film. After oxygen plasma pattern transfer, features with resolution below 0.50 &mgr;m have been obtained with a 0.35 numerical aperture projection system. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116452

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Fine structures appearing on the phase transition fromh(hexagonal) toc(cubic) boron nitride under high pressure (7.7 GPa) and high temperature (1800–2150 °C) are examined by high‐resolution transmission electron microscopy. A prominent contraction of the interplanar spacing betweensp2sheets from 3.33 to 3.10 A˚ in so‐called ‘‘compressedh‐BN’’ is attributable to a monoclinic lattice distortion of the residualh‐BN, which originates from the difference in the compressibility as well as the thermal expansion between adjoiningh‐ andc‐BN grains. The parameters of the monoclinic unit cell aream=4.33,bm=2.50,cm=3.1–3.3 A˚, and &bgr;=92–95°. Thin plates ofh‐BN are often folded and the folding also causes the monoclinic structure. The sheet sequence ofr(rhombohedral)‐BN locally appears when the strong volume shrinkage occurs due to the formation of ac‐BN grain. Nanoscale twins appear in resultingc‐BN grains, as long as they are small, andw(wurzite)‐BN is sometimes included in them. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116453

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We determine the structures present in smectic C‐filled liquid crystal cells under the assumption of strong surface anchoring conditions. This is more realistic than commonly used assumptions and allows the prediction of the near surface alignment structure in such cells. The director orientation structure as a function of surface pretilt is discussed and the energies of the states that exist presented. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116454

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A nanometer scale metal/Langmuir‐Blodgett (LB) film/metal structure is realized with an atomic force microscope combined with scanning tunneling microscope (AFM/STM). Even in this nanometer scale configuration, increase in conductance can be induced at any point in the LB film by application of a voltage pulse. The AFM/STM observation shows little surface modification has occurred by the voltage application, which shows that the conductance of the LB film changes without pit formation in the LB film or metal cluster deposition from the tip of the probe. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116455

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

X‐ray diffraction measurements in the region of small incidence and exit angles on thin amorphous silicon/germanium films on laterally structured surfaces are performed. From fits of the data we obtain directly how the Fourier components of the substrates propagate through the evaporated films without being influenced by the intrinsic statistical roughness of the interfaces. The results show that a replication factor extracted from a given model can be quantitatively tested with our measurements. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116456

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Hydrogenated amorphous silicon (a‐Si:H) films were deposited by a modified pulsed plasma decomposition of silane and disilane in which a nonzero low power level was maintained throughout the discharge. Deposition rate (rd), optical band gap (Eg), dark and photoconductivity (&sgr;Dand &sgr;ph), and photosensitivity (&sgr;ph/&sgr;D) were investigated as a function of pulse parameters. By combining dwell time (&tgr;) and the high power level (HPL) it has been shown thatEgcan be tailored over a fairly wide range. Similarly, &sgr;Dand &sgr;ph/&sgr;Dhave been shown to depend, in addition to HPL, on &tgr; as well, thereby proving the possibility of using &tgr; as an additional process parameter. High band‐gapa‐Si:H material of quality (&sgr;ph=4.4×10−6&OHgr;−1 cm−1, &sgr;ph/&sgr;D≊105) comparable to that of device qualitya‐Si:C:H has been deposited by this technique. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116457

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A reduction of the adhesion between polysilicon surface‐micromachined structures and its silicon substrate using ultrashort pulse laser irradiation has been demonstrated. Polysilicon cantilevers, which adhered to the silicon substrate after final rinse and dry, were freed after irradiation by a 800 nm wavelength laser with pulse duration of 150 fs (full width at half‐maximum) and fluences up to 40 mJ/cm2. Increasing the pulse widths to 2.7 ps resulted in significantly fewer freed cantilevers indicating that the process depends heavily on the presence of high‐temperature carriers in the silicon. Adhesion reduction has been observed from exposure to a single pulse which results in minimal lattice temperature increase. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116458

出版商:AIP    

年代:1996

数据来源: AIP