摘要:

The velocity distribution of sputtered Na atoms from NaCl during 15 keV, Ar+bombardment was measured by a Doppler shift laser fluorescence technique. Contrary to other measurements, the sputtered Na atoms were found to have a velocity distribution identical to that of a three‐dimensional Maxwell–Boltzmann gas.

ISSN:0003-6951    

DOI:10.1063/1.92855

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The electronic level of interstitial Cr in silicon according to the transition Cr0i→Cr+i(3d6→3d5) was determined by correlating the electron paramagnetic resonance (EPR) signal of Cr+to Hall measurements on identical samples. The procedure gives the donor level located atEc−0.222±0.005 eV. From the experiments may be inferred that there is no Cr++istate aboveEv+0.05 eV. The solubility of interstitial Cr in silicon is retrograde at 1300° and has a maximum value of 5×1015cm−3.

ISSN:0003-6951    

DOI:10.1063/1.92856

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The electrical evaluation of metal‐oxide‐semiconductor (MOS) capacitors fabricated on thin films formed by low‐temperature epitaxial crystallization of amorphized polysilicon layers on single‐crystal Si substrates is presented. Shallow dopant and deep‐level defect distributions are obtained using fastC(V) and deep‐level transient spectroscopy, respectively. The dominant deep‐level defects are observed to be atEc−0.074 eV,Ec−0.15 eV, andEc−0.46 eV. Both the shallow dopant and deep‐level defect distributions exhibit peak concentrations near the original poly/single‐crystal interface. These defects and impurities are attributed to gettering by oxygen of contaminant impurities. It is concluded from the data that these films are of suitable quality for MOS device fabrication, and techniques are suggested to further decrease the observed defect concentrations.

ISSN:0003-6951    

DOI:10.1063/1.92857

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We report low field transport properties ofn‐channel GaAs‐AlxGa1−xAs heterojunction field‐effect transistors. Studies of the Shubnikov‐de Haas effect confirm that the devices are insulated‐gate field‐effect transistors, with AlxGa1−xAs as the gate insulator. The channel mobility increases with density following &mgr;2∼n&ggr;, with &ggr; varying from 0.45 to 1.4. &mgr; = 1.2×105cm2/V sec at 78 K and 3.6×105cm2/V sec at 4.2 K are observed atn∼4×1011/cm2.

ISSN:0003-6951    

DOI:10.1063/1.92858

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Atom depth distributions of Se implanted into GaAs show that the deep sides of the depth distributions are the result of interstitial diffusion of Se during implantation of crystalline GaAs. The effect saturates at an ion fluence of ∼1014cm−2for 25 °C implants and continues uninhibited up to the 1016cm−2fluence for 250 °C implantation temperature, implying that the GaAs implantation damage is annealed during implantation at 250 °C. Annealed Se profiles are unchanged for all fluences for both 25 and 250 °C implantation temperatures. Se implants into a self‐amorphized GaAs surface yield more abrupt profiles than corresponding ones into crystalline GaAs, further indicating that when crystal channels are absent, implant tails are absent. Sulfur implants into crystalline and amorphized GaAs held at −130, 25, and 250 °C show that S behaves like Se for the unannealed case; the profiles for implants into crystalline GaAs are deeper the higher the substrate temperature during implantation, implying that diffusion or migration occurs during implantation. In contrast to the results for Se, the annealed S profiles redistribute significantly, characterized both by diffusion deeper into the GaAs and by redistribution toward the surface. These redistributions are significantly impeded by either a cold substrate temperature during implantation or by prior amorphization of the GaAs at any implantation temperature.

ISSN:0003-6951    

DOI:10.1063/1.92859

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A high‐sensitivity, ablative dye‐in‐polymer film which can be written and read with a GaAs diode laser has been identified and evaluated. A 105‐nm‐thick antireflecting film, consisting of 20% of a carbocyanine dye (NK1748) dissolved in poly(vinyl acetate) on an aluminized glass substrate, was ∼3.5 times more sensitive at 835 nm than a 15‐nm Te monolayer on a poly(methyl methacrylate) substrate; submicron marks were recorded. The signal contrast (Rf−Ri) /(Rf+Ri) of large marks in the plateau region was ∼0.5. Morphological studies show the expected removal of recording material in the process of mark formation.

ISSN:0003-6951    

DOI:10.1063/1.92860

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The electron‐hole recombination has been investigated in reactively sputtered hydrogenated amorphous silicon (a‐SiHx) metal Schottky barrier solar cell structures. We find that electron‐hole recombination proceeds through states in the middle of the gap. These states, whose density depends on the degree of hydrogenation, have been associated with Si dangling bonds and their effective carrier capture cross section was estimated to be 6×10−15cm2.

ISSN:0003-6951    

DOI:10.1063/1.92861

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

In this letter, we show that explosive crystallization can occur sequentially along the same laser scan line either from the liquid phase or in the solid phase. Which phase dominates depends on the laser scan speed, the proximity of thea‐Si melting isotherm, and the magnitude of the ’’thermal kick’’ provided by fluctuations in laser power or at localized regions of higher absorption.

ISSN:0003-6951    

DOI:10.1063/1.92862

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The experimental observations of metallurgical interactions between compound semiconductor substrates and metallic or oxide overlayers have stimulated a new model of Fermi level ’’pinning’’ at these interfaces. This model assumes the standard Schottky picture of interface band alignment, but that the interface phases involved are not the pure metal or oxide normally assumed by other models. For both III‐V and II‐VI compounds, the barrier height to gold is found to correlate well with the anion work function, suggesting the interface phases are often anion rich. This correlation holds even for cases in which the ’’common anion rule’’ fails, and explains both successes and failures of this earlier model.

ISSN:0003-6951    

DOI:10.1063/1.92863

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The effects of cw CO2andQ‐switched ruby laser beam irradiation on donor (B, In) and acceptor (P) ion‐implanted Hg1−xCdxTe (x= 0.2, 0.3) are reported. Rutherford backscattering and particle induced x‐ray emission measurements for channeled and nonchanneled particles were used to investigate the crystal quality and its composition near the surface. It is shown that annealing by cw CO2laser irradiation (120 W/cm2, 0.2 s) results in good crystal regrowth. Irradiation by light from pulsed ruby lasers (0.15 J/cm2, 50 ns) even though to a certain extent does anneal the damage, is accompanied by the dislodging of Hg atoms from the near‐surface region. The present results thus explain our findings that electrical activation of donor and acceptor implants in HgCdTe can be achieved by cw CO2laser annealing, but not by pulsed ruby laser irradiations.

ISSN:0003-6951    

DOI:10.1063/1.92864

出版商:AIP    

年代:1981

数据来源: AIP