摘要:

Precise determinations by x‐ray photoelectron spectroscopy of the Auger parameter for silicon, using a combination magnesium–gold x‐ray source, disclose significant differences among values for crystalline, amorphous, and sputtered silicon. Detectable differences were found for silicon as an oxide for oxide films of different thickness. These differences appear to be due to the effect of disorder upon the polarizability of the atomic environment. The sharp change in polarizability across the silicon–silicon oxide interface would tend to broaden greatly the spectral lines from interface species; any observation of distinct lines from the interface requires three‐dimensional aggregates in multiatom dimension, or an extremely ordered layered structure in the transition region. Silicon as a silicide has a parameter value more than 1 eV larger than that of crystalline silicon. Shifts in the values for the associated metal atoms are also indicated. The technique thus offers another way to examine physical and chemical states in surface layers.

ISSN:1071-1023    

DOI:10.1116/1.582927

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

Current–voltage characteristics of an inverted GaAs–AlGaAs modulation doped transistor are calculated using a charge control model. Our calculations show that the electron concentration of the two dimensional electron gas for the inverted structure is comparable to those obtained in normal MODFET’s. The optimum design of an inverted device calls for a doped AlGaAs layer thin enough to be fully depleted. The sheet carrier concentration of the two dimensional electron gas will be only slightly less than the maximum possible. For such devices the predicted transconductances are close to those for normal modulation doped transistors.

ISSN:1071-1023    

DOI:10.1116/1.582928

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

In single GaAs quantum wells sandwiched between relatively thick AlxGa1−xAs, only weak photoluminescence which is dominated by extrinsic processes is observed. This is attributed to a degraded interface at the bottom AlGaAs/GaAs heterojunction. The situation worsens when the thickness of the bottom AlGaAs layer is increased, the GaAs thickness is reduced, or the Al mole fraction is increased. Inserting a graded three‐period superlattice between the AlGaAs and GaAs quantum well at the bottom interface causes the intensity of the photoluminescence associated with exciton recombination to increase to more than 160 times that in the conventional quantum well. Furthermore, the impurity related photoluminescence from the improved quantum well is almost entirely absent; the photoluminescence is dominated by the recombination of the ground staten=1 heavy‐hole free exciton. This dramatic improvement is indicative of the improvement of the interface resulting from the insertion of a thin superlattice.

ISSN:1071-1023    

DOI:10.1116/1.582929

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

An electron‐beam‐lithography‐compatible process for the fabrication of depletion mode and accumulation mode insulated gate field effect transisitors on InP has been developed and is reported in detail. The exposure system uses an unmodified scanning electron microscope interfaced with a minicomputer. Transistor gate length dimensions for the completed devices range from several microns to submicron, and the smallest gate length for the depletion mode device measures 0.25 μm. Device operation is presented and discussed, and device performance is shown to compare well with long gate devices made by optical lithography.

ISSN:1071-1023    

DOI:10.1116/1.582930

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

A novel technique of selective SiO2formation called the interfacial oxidation method is proposed and proved feasible by experiment. By this technique, a poly‐Si/MoO2/Mo structure (poly‐Si on MoO2on Mo) can be converted to a poly‐Si/SiO2/Mo structure by annealing in an H2atmosphere so that SiO2is selectively formed on only Mo electrodes. The SiO2film formed by this method is shown to have almost the same properties as thermally grown SiO2film; the Si(2p) binding energy peak, etching rate for diluted HF(H2O:HF=100:3), and average breakdown strength were 102.9 eV, 102 Å/min, and 3.6×106V/cm, respectively. In addition, most diodes of 500×500  μm2area showed a leakage current of less than 10−12A.

ISSN:1071-1023    

DOI:10.1116/1.582931

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

Isothermal changes in tensile stresses depending on the amount of MoSi2formed in sputter deposited films which have multilayered structures of molybdenum and silicon (atomic ratio, Si/Mo=2) have been investigated. The amount of MoSi2formed in the films was controlled isothermally by changing a layer thickness parametert* from 0 to 220 Å which was the sum of both the molybdenum layer and silicon layer thicknesses. The films were deposited on oxidized silicon wafers and sintered in the temperature range 440–1000 °C. The tensile stress increases to 1.5×1010dyn cm−2linearly with increasing 1/t* and saturates with further increase in 1/t*. Since 1/t* is proportional to the amount of MoSi2formed in the films, the stress is found to increase with an increasing amount of crystallized MoSi2in the films and to saturate when the whole multilayered films are completely converted into MoSi2films. Furthermore, it is suggested that relaxation of the tensile stress occurs in proportion to the amount of crystallized MoSi2.

ISSN:1071-1023    

DOI:10.1116/1.582932

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

This paper is concerned with the choice and influence of the deposition conditions of ITO thin films ontop‐type single crystal InP substrates for use as heterojunction solar cells. Our analyses, based on capacitance–voltage, current–voltage, spectral response, surface photovoltage, and reflection electron diffraction, indicate that adverse effects of the deposition process on the surface can be reduced by proper choice of deposition schedule. The general conclusions are (1) The reverse saturation current is 2–3 orders of magnitude lower for cells fabricated by using very low power deposition of the ITO than for those using high power deposition. (2) Either abrupt or graded interfaces can be formed depending on the input power to the sputtering process. (3) The extent of the grading increases with increased rf power input and is believed to be due to the diffusion of species (possibly of tin).

ISSN:1071-1023    

DOI:10.1116/1.582933

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

The principles of mass spectrometry are discussed and applied to the problem of assuring the purity of ion beam species in ion implantation. Experimental confirmation of various ion dissociation and charge exchange phenomena is presented for the case of a SiF4plasma used to produce Si ions for doping GaAs. Techniques for recognizing spurious ion species are explained.

ISSN:1071-1023    

DOI:10.1116/1.582934

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

ISSN:1071-1023    

DOI:10.1116/1.582936

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

ISSN:1071-1023    

DOI:10.1116/1.582937

出版商:American Vacuum Society    

年代:1984

数据来源: AIP