摘要:

A novel and economical method for the preparation of the hydrogenated amorphous silicon films by glow discharge composition of silane in two reactors connected in cascade is presented. Whereas the films obtained from the first reactor have nearly the same dark and photoconductivity as reported in literature, those from the second reactor exhibit four orders less dark conductivity and one order less photoconductivity for the same deposition conditions.

ISSN:0003-6951    

DOI:10.1063/1.94623

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A new laser recrystallizing technique for producing single crystalline Si islands on an amorphous insulating layer has been developed. Si islands are recrystallized by indirect Ar ion laser heating utilizing a Si cap. This technique is an effective recrystallizing method for fabricating three‐dimensional integrated circuits. During recrystallization, this technique easily and stably produces a desired temperature profile to eliminate grain boundaries in recrystallized Si islands; the interior of the Si islands is kept cooler than the periphery and crystal growth begins from the interior. This desired temperature profile is realized because an Ar ion laser power is absorbed in the Si cap and heat flow takes place to the Si islands laterally as well as vertically from the heated Si cap through a separation cap. Damage to the underlying layer is not observed, which suggests that the laser beam power is cut in the Si cap. No grain boundaries are observed in more than 90% of the Si islands recrystallized with such an arrangement that laser beam traces include Si islands; the size of the islands is 20×60 &mgr;m. Field effect mobility of 460 cm2/Vs is obtained for Si on insulator/metal‐oxide‐semiconductor field‐effect transistors fabricated in the recrystallized Si islands with this technique.

ISSN:0003-6951    

DOI:10.1063/1.94624

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The diffusion profile of Hg in CdTe crystals was observed by means of heavy ion (40 MeV O5+) backscattering. The near‐surface region of CdTe immersed in Hg was investigated up to 1.4 &mgr;m from the surface. The observed Hg profile indicated that the concentration of Hg atom at the surface reached 4×1020cm−3and the distribution was interpreted by a simple diffusion model. Temperature dependence of the diffusion coefficient was determined to beD=5×103 exp[(−2.0±0.3) eV/kT] (cm2/s). In the case of CdTe immersed in Hg which contained a small amount of Cd, it was found that Hg diffusion did not occur. These experimental facts suggest that the rate of Hg diffusion is controlled by the diffusion of a Cd vacancy which is introduced by the outdiffusion of Cd atoms from CdTe crystals.

ISSN:0003-6951    

DOI:10.1063/1.94595

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The nonlinear recovery dynamics of optically excited carriers in thin layer samples of GaInAsP (1.3 &mgr;m, 1.55 &mgr;m) and GaInAs (1.65 &mgr;m) have been studied by picosecond optical pump‐probe measurements of absorption bleaching using pulses at 1.06 &mgr;m for both pump and probe. An evaluation of the data was performed by a careful computer model which takes into account the temporal development of the carrier density and absorption, the spatial averaging of the bleaching, and a convolution with the probe beam. The effective Auger coefficients, determined as curve fitting parameters, were found to beA(1.3 &mgr;m)=1.5×10−29cm6/s,A(1.55 &mgr;m) =7.5×10−29cm6/s, andA(1.65 &mgr;m)=9.8×10−29cm6/s.

ISSN:0003-6951    

DOI:10.1063/1.94596

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The Schottky‐barrier height &fgr;Bof ideal (no interfacial oxide) contacts to GaAs has been measured for a diverse group of eleven metals, Cu, Pd, Ag, Au, Al, Ti, Pb, Bi, Ni, Cr, and Fe, by using current‐voltage and capacitance‐voltage techniques. The contacts were formed by metal evaporation in ultrahigh vacuum onto clean (100) surfaces of bothn‐type andp‐type GaAs. Forn‐type contacts &fgr;Branged from 0.96 to 0.72 eV, in the metal order listed above; forp‐type contacts &fgr;Branged from 0.45 to 0.62 eV. No simple correlation was found between &fgr;Band metal work function nor between &fgr;Band the chemical reactivity at the metal‐GaAs interface.

ISSN:0003-6951    

DOI:10.1063/1.94599

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Shallow‐emitter, narrow‐basenpnbipolar transistor structures have been obtained by implantation of B+and As+ions into amorphous Si layers formed by the prior implantation of Si+ions. Thermal annealing results in recrystallization of the amorphous layers by solid phase epitaxy and activation of the implanted dopant atoms. Emitter‐base junction depths and base widths of ∼0.10 &mgr;m, as determined by secondary ion mass spectroscopy analysis, have been achieved both for single‐crystal Si samples and for samples with poly‐Si emitter contacts. Transmission electron microscopy shows that the recrystallized layers are almost free of defects near the emitter‐base and base‐collector junctions. Discrete bipolar transistors with good electrical characteristics have been fabricated using this technique.

ISSN:0003-6951    

DOI:10.1063/1.94600

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We present a new dc superconducting quantum interference device (SQUID) configured as a susceptometer for the study of the magnetic properties of small (<10 &mgr;m) particles and thin‐film samples. The SQUID consists of two series pick‐up loops wound in opposite sense over a hole in the groundplane and connected to remotely located tunnel junctions by low inductance transmission lines. An integrated field coil with provision for balance allows application of a magnetic field of 0–30 G to a sample positioned in either pick‐up loop. For an applied field of 5 G the device having an intrinsic energy sensitivity of ∼25 h is able to resolve the superconducting transition of a 5‐&mgr;m tin particle with a signal‐to‐noise ratio of ∼106.

ISSN:0003-6951    

DOI:10.1063/1.94601

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

100‐keVe‐beam lithography and electroplating of gold have been used to fabricate a device for the measurement of quantum changes in magnetic flux. The structure is defined in a 200‐nm‐thick layer of a copolymer of methyl methacrylate and methacrylic acid (PMMA/MAA) on top of a Si wafer covered by 150 nm of Si3N4. The device is a square frame of 2×2 &mgr;m2and 100‐nm linewidth. Gold was electroplated to a thickness of 100 nm. This technique allows the fabrication of high resolution, high aspect ratio gold structures.

ISSN:0003-6951    

DOI:10.1063/1.94602

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The design and test of a microwave electrothermal thruster are described. The device, which employs a coaxial microwave discharge, was tested in nitrogen gas with 200–600 W of 2.45‐GHz input power. Experimental measurements of thrust, specific impulse, and energy efficiency are presented for different flow and discharge pressures. Measured energy efficiencies varied between 30%–60% and the performance compared favorably with other electrothermal thrusters operating in nitrogen gas. The experimental performance demonstrated the feasibility of the concept.

ISSN:0003-6951    

DOI:10.1063/1.94603

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Strongly intensity‐dependent photobleaching was observed in polymethyl methacrylate films doped with acridine and irradiated by a KrF laser. The transmission of low intensity pulses (<2 MW/cm2) increased from <0.01% to 60% as the intensity of a single prior bleaching pulse increased from 3 to 4 MW/cm2. The implications of this result for image enhancement in excimer laser projection photolithography are discussed: features in the region of 0.2–0.3 &mgr;m may be printable by such techniques.

ISSN:0003-6951    

DOI:10.1063/1.94604

出版商:AIP    

年代:1984

数据来源: AIP