摘要:

Ohmic contacts with low specific‐contact resistivity and with contact morphology superior to conventionally alloyed contacts have been made ton‐type GaAs by sintering AuGe films on GaAs at 315 and 330 °C for several hours. The specific contact resistivities were found to decrease with sintering time and values as low as 3×10−6&OHgr; cm2were obtained for contacts on GaAs (doped with silicon to a concentration of 1018cm−3) after sintering at 330 °C for 1 h. Secondary Ion Mass Spectrometry profiling of the sintered films has been used to show that the ohmic contact formation is due to an enhanced diffusion of Ge into GaAs.

ISSN:0021-8979    

DOI:10.1063/1.329989

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The exchange constantsJTTJTR, andJRRin the garnet seriesR3Fe5O12(R= Y3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, or Yb3+) have been obtained using the molecular field approximation. The low‐temperature magnetization data for all the garnets except Y and Gd garnets have been fitted assuming a temperature‐dependent canting on the rare‐earth sublattice. These exchange constants are found to be comparable to those obtained for the rare‐earth intermetallicRFe4Al8.

ISSN:0021-8979    

DOI:10.1063/1.329990

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Visible emission measurements from the rear surface of laser‐irradiated thin transparent target foils show a transient light flash followed by secondary light emission due to rear surface heating. This temporal signature is different from that reported in shock experiments in transparent solids. Rear surface temperature determinations versus time on laser‐accelerated CH targets are presented.

ISSN:0021-8979    

DOI:10.1063/1.329991

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The optical emission close to the Taylor cone tips of liquid gallium and gold ion sources has been studied as a function of wavelength and ion current. The optical emission may be interpreted as due to excitations caused by binary collisions, among which Ga‐Ga+collisions play a dominant role. The release rate of neutrals from the source inferred from the optical‐emission curves is consistent with the idea of contributions to the total ion current from field evaporation and field ionization, with the latter becoming increasingly important at higher currents. It is difficult to account for the origin of the neutrals by thermal evaporation at the tip.

ISSN:0021-8979    

DOI:10.1063/1.329992

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

We present a simple way to evaluate the spin‐mixing parameter, &egr;, of the optical cycle of theFcenter in alkali halides in the case of strong optical absorption. Usually a small optical absorption is required in the commonly used method, based on the monitoring of the magnetic circular dichroism, to determine the value of &egr;.

ISSN:0021-8979    

DOI:10.1063/1.329993

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Rutherford backscattering measurements have revealed that the buried amorphous layer formed in the silicon‐on‐sapphire (SOS) film by oxygen implantation with a dose of 1×1015/cm2at 130 K reorders epitaxially from the surface, and crystalline quality is improved in the entire region of the SOS film after annealing at 1000 °C for 20 min in N2. But in the case of implantation with a dose of 1×1016/cm2at room temperature, the high concentration of oxygen prevents the reordering and as a result the crystalline quality improvement is limited only in the surface region. Energy dependence of the dechanneled fraction shows that the type of defects in Si near the Si/sapphire interface has changed probably from microtwins or stacking faults to dislocation loops after reordering.

ISSN:0021-8979    

DOI:10.1063/1.329994

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The vacuum deposition of metals onto poly (dimethylsiloxane) (PDMS) gels was studied as a function of the crosslink density and the polymer substrate temperature during the deposition. Reflectance and conductance measurements were used to characterize the quality of the resulting metal films. Variations in the measurements were found to depend on the substrate temperature during metallization and on the particular metal used. For most cases, the variations of conductance and reflectance can be accounted for by cracks in the metal film and the coarseness of the surface texture.

ISSN:0021-8979    

DOI:10.1063/1.329995

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Oxide charge generation resulting from the exposure of Si/SiO2structures to scanning electron and laser beams during the anneal of ion implantation damage was investigated. Fixed oxide charge, interface trapped charge, and oxide trapped charge densities were measured by use of high‐frequency, quasistaticC‐V, and avalanche carrier injection techniques. The effective density of traps induced by the exposure of thin oxides to electron beam fluences of 0.39–3.10×10−2C/cm2at 5 kV was found to be an order of magnitude larger than in control wafers. This effect was primarily due to neutral trap formation. Although interface charges could be reduced to an acceptable level by a post‐irradiation anneal (400 to 500 °C) in forming gas, neutral traps could not be annealed satisfactorily. It was also found that scanned electron‐beam annealing from the backside of the wafer or laser annealing constitute viable alternatives with minimal effects on the densities of fixed oxide charges in the silicon dioxide layer.

ISSN:0021-8979    

DOI:10.1063/1.329996

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

An electrochromic display based on a Prussian‐blue‐modified electrode is described. Prussian blues are deposited electrochemically in a solution of ferric‐ferricyanide. Current flow at +0.2 and +1.0 V is due to the reduction of Fe3+and the oxidation of Fe2+in the Prussian‐blue coating, respectively. The result is a display that switches from clear to blue, has high stability, and has a response of less than 100 ms.

ISSN:0021-8979    

DOI:10.1063/1.329997

出版商:AIP    

年代:1982

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.331650

出版商:AIP    

年代:1982

数据来源: AIP