摘要:

The problem of how defect concentrations produced in a shock experiment affect the isothermal equation of state is considered. From the few experimental results available that bear directly on this question, it appears the effect could be substantial, i.e., the pressure in material free of defects may be 10–25% lower at a given volume than the isothermal pressure deduced from Hugoniot data on the assumption that defects are negligible in the shocked material. This correction caused by the presence of defects is called the defect pressure.

ISSN:0021-8979    

DOI:10.1063/1.327605

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

An x‐ray diffraction topography goniometer (Lang camera) under computer control has been used to measure localized bending of silicon wafers. The wafer, mounted free from external stresses, is set for Bragg reflection in transmission by lattice planes perpendicular to the surface (Laue case) and it traverses across the x‐ray beam in steps of 0.01 mm or multiples thereof. At each step the angular position and the intensity of the peak of the Bragg reflection is determined by least‐squares methods from the peak profile with a precision better than the minimum angular step of 0.001°. The lattice curvature obtained from the peak shift is a direct measure of the magnitude of the strains imposed on the wafer by oxide layers, thin films, implantation, and other manufacturing processes. Therefore linear strain maps, showing, for instance, strain gradients occurring at film edges, can be measured quantitatively with high resolution, fully automatically and nondestructively in several direction across a substrate wafer. Measuring substrates of high crystalline perfection and controlling the ambient temperature, the radius of curvatureR(in meters) of a uniformly curved substrate can be measured with a probable relative error &Dgr;R/R=R/(1700 m).

ISSN:0021-8979    

DOI:10.1063/1.327606

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

An observation by micro‐Auger electron spectroscopy has been made of the tin whisker grown on electroplated tin films. Direct experimental evidence has been obtained for the existence of zinc and oxygen impurities on tin whiskers as well as on the electroplated film surfaces when a brass or zinc‐coated metal is used as a substrate. The localization of these impurities on these surfaces may be related to the growth mechanism of tin whiskers or to the driving force by lowering the surface energy.

ISSN:0021-8979    

DOI:10.1063/1.327607

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

We report the application of diode admittance spectroscopy in characterizing traps in Hg1−xCdxTe. Measurements performed onn+‐pjunction photodiodes have identified a hole trap located 0.16 eV above the valence band inx=0.305 liquid‐phase‐epitaxy‐grown material and a single hole trap located 0.046 eV above the valence band inx=0.219 bulk‐grown material. Measurements of trap density and majority‐carrier capture cross section have also been carried out, with results suggesting hole capture at a neutral trapping center. Trap energies determined by the admittance spectroscopy technique were found to be in good agreement with lifetime‐versus‐temperature data analyzed in terms of a single Shockley‐Read recombination center.

ISSN:0021-8979    

DOI:10.1063/1.327608

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Profiles of deep energy states in selenium diffused siliconp+njunctions have been studied by junction capacitance techniques and secondary ion mass spectroscopy (SIMS). In both cases similar profiles are obtained. Since the profiles measured by SIMS are due to selenium atoms, it is concluded that selenium is responsible for the two dominant energy levels previously investigated in Si:Se by junction space‐charge techniques.

ISSN:0021-8979    

DOI:10.1063/1.327609

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Tin oxide films have been prepared on glass substrates by spray pyrolysis technique. The electrical and optical properties of undoped and antimony‐doped tin oxide films have been studied. The temperature dependence of electron mobility has been analyzed to establish the electron conduction mechanism. Optical properties near the plasma edge have been analyzed using Drude’s theory. The dependence of effective mass on carrier concentration has been explained on the basis of nonparabolicity of the conduction band. The shift in the Fermi energy, calculated on the basis of energy dependent effective mass, is consistent with the measured shift in the absorption edge.

ISSN:0021-8979    

DOI:10.1063/1.327610

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

There is still considerable disagreement in the published values for the energy position and capture cross section of the gold‐acceptor level in silicon. We have measured in a rather direct way the thermal emission rateenfor electrons andepfor holes in the 240–360 °K temperature range on gold‐contaminated MOS and Schottky structures. The results can be well explained by the single‐level Shockley‐Read‐Hall model when pinning the gold level either to the conduction band or to the valence band. That is the reason why there are various interpretations while crude results forenandepare in good agreement. For instance, depending on the case, the gold energy level is found to be 0.553 or 0.476 eV below the conduction band at 300 °K: these are the extreme published values. From a practical point of view, we show that at concentrations as low as 1010cm−3, gold is the major impurity controlling the generation lifetime in silicon devices.

ISSN:0021-8979    

DOI:10.1063/1.327611

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

It is pointed out that the electron trapping characteristics (&Dgr;VFB‐Ninjcurve) depend on the pulse frequency and the pulse width of the gate voltage used in avalanche hot electron injection from the Si substrate into the SiO2film, while the generation of the interface states depends very little on those factors. It is shown that those correlations are mainly due to the discharge of trapped electrons during the zero‐bias state between pulses. The experimental results of the discharge of trapped electrons are also described and are explained by means of a modified discharge theory of MNOS structures.

ISSN:0021-8979    

DOI:10.1063/1.327612

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

We analyze the excess‐carrier charge transport through the space‐charge region of a semiconducting electrode using a technique known as the flux method. In this approach reflection and transmission coefficients appropriate for a sheet of uniform semiconducting material are used to describe the transport properties of that material. We give a brief review of the flux method and show that the results obtained using this approach for a semiconductor electrode reduce in a limiting case to those previously found by Ga¨rtner if the depletion layer is treated as a perfectly transmitting medium in which scattering and recombination are ignored. Then, in the framework of the flux method we treat the depletion layer more realistically by explicitly taking into account scattering and recombination processes which occur in this region.

ISSN:0021-8979    

DOI:10.1063/1.327613

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

By means of a recently developed experimental technique, the dependence on the energy and electric field of Si‐SiO2interface state capture cross sections has been measured for Al‐SiO2‐nSi structures with an oxide thickness ?800 A˚. The capture cross section for holes,&sgr;p, has been observed to be several orders of magnitude larger than that for electron, &sgr;n, and further it has been observed to show a strong dependence on energy in the upper half of the silicon energy gap. This apparent dependence of &sgr;pon energy has been shown to arise primarily from a dependence on the electric field at the semiconductor surface. For the same electric field, interface states at different energies in the gap are observed to have very nearly the same magnitude of capture cross section.

ISSN:0021-8979    

DOI:10.1063/1.327614

出版商:AIP    

年代:1980

数据来源: AIP