摘要:

We have made a detailed study of the effects of photon radiation in the energy range between 0.5 and 5.0 eV on InSb metal‐oxide‐semiconductor (MOS) devices. Measurements of the photocurrent through the MOS structures made at several temperatures showed that even at 300°K a photovoltage is developed for photon energies greater than about 1.3 eV. For photon energies above 3 eV the indium‐antimony oxide layer became photoconductive. The charging and discharging characteristics of the InSb‐oxide interface were investigated by measuring the response of the InSb&sngbnd;MOS structure to modulated long wavelength (3.9 &mgr;) radiation. This radiation acts as a probe for examining the band bending in the InSb at the InSb‐oxide interface, which in turn depends on the amount of charge trapped in the oxide or at the interface. When the MOS structure is irradiated with 1.3‐ to 4‐eV photons, the oxide and/or the interface becomes negatively charged. At photon energies above 3.5 eV there is a competition between the mechanism which induces negative charge in the oxide and/or interface region and the mechanism which releases this charge. This competition can be influenced by applied bias, and by properly biasing the device and irradiating with photons having energies greater than 4 eV the charges can be released.

ISSN:0021-8979    

DOI:10.1063/1.1658254

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

An approximate analysis is presented for spherical and cylindrical electrostatic probe operation under conditions such that large collision‐dominated sheaths are obtained. Analytical expressions are given for the sheath growth as a function of experimentally determined parameters. If pressure and temperatures are known, use of these results makes possible the direct interpretation of electron number density from a single probe measurement.

ISSN:0021-8979    

DOI:10.1063/1.1658255

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The temperature of a laser‐heated carbon plasma, formed by the interaction between aQ‐switched ruby laser and a pyrolytic graphite slab, has been measured using interferometric, spectroscopic, and energy conservation techniques. Results indicate that the maximum plasma temperature is less than 10 eV. A method of determining whether the plasma is in thermodynamic equilibrium is employed and indicates that at laser fluxes of 109W/cm2the plasma is not in LTE with the electron temperature nearly an order‐of‐magnitude larger than the plasma temperature. For fluxes of 1010W/cm2, however, the plasma appears to approach a state of thermodynamic equilibrium with a temperature of 2eV.

ISSN:0021-8979    

DOI:10.1063/1.1658256

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Experimental observations of the normal modes in a cylindrical plasma without external excitation is presented. The experimental results compare favorably with theory. Measurement of the high‐frequency electromagnetic field outside of the plasma and its spectrum lead to a method of measuring the electrostatic oscillations spectrum in a plasma without perturbing it in any way. Exact measurement of the emission profile at the plasma frequency can give information about the mean thermal speed of the electrons without any assumption about their distribution function.

ISSN:0021-8979    

DOI:10.1063/1.1658257

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

An analytical method is developed to determine the gas temperature distribution and the electric field strength‐arc length characteristics of a rotationally stabilized long plasma arc in a cylindrical chamber. The application of the method was demonstrated by numerical computations which were carried out for a monatomic hydrogen arc stabilized in a very large chamber. The relationships among the electric field strength, current, arc length, and arc‐axis temperature are disclosed.

ISSN:0021-8979    

DOI:10.1063/1.1658258

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

With the new application of capacitance‐change techniques, length‐change measurements were made in conjunction with annealing copper and aluminum specimens above their electron‐irradiation temperature of about 15°K. Damage rates at this temperature were also measured. The Stage I recovery of length change is compared with its resistivity counterpart. Remarkable correspondence is obtained to the degree that percentages of recovery of individual substages compare favorably, with the same defect inferred to be responsible for recovery in both cases. The production rate for length change was determined to be +1.8×10−23cm2/electron for 2.2 MeV electrons. Linear bending with dose was observed. This bending was analyzed as due to electron straggling. The ratio of resistivity change to volume change and to stored energy for electron and heavy‐particle bombardment shows good relative agreement. From the results, it was concluded that these physical‐property changes do not depend sensitively upon Frenkel pair close‐pair separation.

ISSN:0021-8979    

DOI:10.1063/1.1658259

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The anneal behavior of layers implanted with dopants from column III (B, Al, Ga, and Tl) and column V (As, Sb, and Bi) in silicon substrates has been investigated. The ranges of implant conditions were energy 20–50 keV, dose 1013–1015/cm2, and substrate temperature 23°–500°C. Hall‐effect and sheet resistivity measurements were used to determine the effective number of carriers/cm2(Ns)effand the effective mobility &mgr;eff. Analysis of nonuniform distributions of carrier densities and mobilities on these measurements shows that the values of (Ns)effand &mgr;effcan be misleading unless the effect of the depth distributions is allowed for. These distributions have been determined in some cases by the use of layer removal techniques combined with Hall‐effect and sheet resistivity measurements. We find in well‐annealed implanted samples that the dependence of the mobility on carrier density follows that determined for bulk silicon. In many cases deviation from this relation can be accounted for on the basis of compensation. In the case of aluminum we suggest that this compensation may be accounted for by the presence of interstitial aluminum atoms acting as donors. We have found that interstitial thallium can behave as a donor. The anneal behavior of the implanted layer is influenced by ion species, dose, and substrate temperature. The carrier concentration measured in implantations of column III elements did not exceed the limits of thermal equilibrium solubility as is found for column V elements. In the former case, enhanced diffusion effects are observed. From the known substitutional behavior of column V elements, it is suggested that the anneal behavior in the 600°–800°C range is due to the dissociation of radiation damage complexes.

ISSN:0021-8979    

DOI:10.1063/1.1658260

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The radiative processes in Si‐compensated,n‐type GaAs prepared by liquid‐phase epitaxy have been studied by photoluminescence between 300° and 4.2°K. The data are consistent with the previous hypothesis of the formation under certain growth conditions of two types of acceptor levels by Si in GaAs (in addition to the shallow donor level) with ionization energies of ∼0.03 and ∼0.1 eV. Three basic radiative processes dominate at various temperatures: (a) Band‐to‐band recombination at 300°K, (b) conduction band (or possibly conduction‐band tail states) to shallow acceptor transitions at 4.2°K, and (c) conduction band to the deeper acceptor transitions at 77°K. The half‐width of the third emission band and its peak position depends on the Si and free‐carrier densities. The degree of compensation of these materials is a function of the substrate orientation. Of the three planes investigated, (100), (111)‐Ga, and (111)‐As, growth on the (111)‐As face results in the lowest degree of compensation. The present study shows thatn‐type material with mobilities in excess of 1000 cm2/V·sec and electron concentration in the 2–4×1018cm−3range can be prepared by growth at 1060°C with the advantage over Te‐ or Se‐doped GaAs that the formation of precipitates of Ga2Se3or Ga2Te3is eliminated. Such precipitates were previously shown to seriously degrade the radiative efficiency and hence the performance of injection lasers and spontaneous emitters.

ISSN:0021-8979    

DOI:10.1063/1.1658261

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

In the presence of an interfacial layer and semiconductor surface states, a Schottky barrier height &phgr;bdecreases with increasing electric fieldEat the surface of the semiconductor. If the semiconductor doping concentrationNdis uniform throughout the depletion region and if[ (qNd/&egr;) (d&phgr;b/dE)−E] [ (d2&phgr;b/dE2) (dE/dV) ]≪1,whereVis the applied voltage and &egr; is the semiconductor permittivity, the slope of the (capacitance)−2vs voltage relationship is constant and can be interpreted to giveNd. The voltage intercept of the relationship yields an apparent barrier height &phgr;arelated to the true barrier &phgr;bby &phgr;a=&phgr;b−E(d&phgr;b/dE) + (qNd/2&egr;) (d&phgr;b/dE)2, whereqis the electron charge. From the measured variation of &phgr;awithNdand one absolute measure of &phgr;bat one value ofNd, &phgr;b(E), andd&phgr;b(E)/dEmay be deduced. Fromd&phgr;b(E)/dEthe surface state density as a function of energy in the bandgap and the minimum value of interface thickness divided by relative interface permittivity can be obtained. Using the data of Archer and Atalla for vacuum cleaved Au‐Si diodes to illustrate our method, the surface state density is found to peak at a value of ∼2×1014cm−2·eV−1at about 0.83 below the conduction band and the minimum value of interface thickness divided by relative dielectric constant is found to be of the order of 5 Å. Criteria are given which show how Schottky diode capacitance‐voltage data may be further used, in conjunction with photoelectric barrier measurements, to detect the presence of deep lying impurities or the penetration of surface state charge into the body of the semiconductor.

ISSN:0021-8979    

DOI:10.1063/1.1658262

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Hole diffusion lengthsLwere determined for several Te‐doped GaAs crystals with electron concentrations ranging from 2×1016to 6.5×1018cm−3. The values ofLwere obtained by fitting experimental photoluminescence spectra to a theoretical expression which contains the measured absorption coefficients. This expression was derived from radiative recombination statistics, taking into account the reabsorption of emitted photons and the diffusion of minority carriers. The idea used by van Roosbroeck and Shockley of introducing the measured absorption coefficient by means of the principle of detailed balance is shown here to be valid for both nondegenerate and degeneraten‐type GaAs. It was found that the hole diffusion lengths are nearly independent of electron concentrationnforn< 1×1018cm−3. This result is attributed to a constant total hole lifetime associated with a nearly constant concentration of ``frozen‐in'' defects. Forn> 2×1018cm−3values for diffusion length decrease rapidly with increasingn. This decrease is attributed to the formation of additional defects associated with donor complexes or precipitates, or both. The diffusion lengths determined in this work are in good agreement with those found by Wittry and Kyser from the electron‐beam excitation method but are larger than those obtained by Aukermanet al. from short‐circuit current measurements onn‐type surface barrier diodes subjected to high‐energy electron bombardment.

ISSN:0021-8979    

DOI:10.1063/1.1658263

出版商:AIP    

年代:1969

数据来源: AIP