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15 Jun 1991

Volume 69, Issue 12, pp. 7973-8429

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Electromagnetic fields for an irregularly shaped, near‐spherical particle illuminated by a focused laser beam

J. P. Barton and D. R. Alexander

J. Appl. Phys. 69, 7973 (1991); http://dx.doi.org/10.1063/1.347493 (14 pages) | Cited 18 times

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A theoretical procedure is derived for the determination of the internal and external electromagnetic fields for a monochromatic beam incident upon a homogeneous particle of arbitrarily‐defined shape. The procedure is best suited for the analysis of near‐spherical particles (i.e., particles which deviate from a sphere by plus or minus a few tenths of a radii). Verification and demonstration calculations are presented. Also presented are calculations investigating the effect of a surface deformation on resonance excitation within an otherwise spherical particle.
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42.25.Fx Diffraction and scattering
03.50.De Classical electromagnetism, Maxwell equations
41.20.Jb Electromagnetic wave propagation; radiowave propagation

The electromagnetic field of a horizontal electric dipole in the presence of a three‐layered region

Ronold W. P. King

J. Appl. Phys. 69, 7987 (1991); http://dx.doi.org/10.1063/1.347494 (9 pages) | Cited 27 times

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The electromagnetic field generated by a horizontal electric dipole in the air over the surface of a two‐layered region is determined for continuous‐wave excitation. The region of interest consists of a conductor coated with an electrically thin layer of dielectric under a half‐space of air. Simple explicit formulas are derived for the field at all points in all three regions, including the surface wave. Typical applications are to microstrip circuits and antennas and to remote sensing from the arctic ice.
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41.20.Gz Magnetostatics; magnetic shielding, magnetic induction, boundary-value problems
85.40.Bh Computer-aided design of microcircuits; layout and modeling

Cl2 reactive ion etching mechanisms studied by in situ determination of ion energy and ion flux

A. Manenschijn, E. van der Drift, G. C. A. M. Janssen, and S. Radelaar

J. Appl. Phys. 69, 7996 (1991); http://dx.doi.org/10.1063/1.347495 (9 pages) | Cited 19 times

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An experimental study of etching mechanisms in Cl2 reactive ion etching is reported. The ion‐impact energy distribution and ion current density have been measured in situ at the rf electrode of a parallel‐plate reactive ion etcher. This diagnostic method has been used for the first time to unravel etch characteristics in a practical etching environment. Samples of Si, SiO2, Ti, and TiSi2 have been etched both in Cl2 and Ar discharges, and the etch rates have been related to the ion flux and impact energy distribution. The angular impact energy distribution for both ions and neutrals has been calculated numerically in order to study the contribution of fast neutrals and the angular distribution of impinging species to the etch rate. Sputter yields have been determined from the observed etch rate and the ion current density, taking into account the (angular) energy distributions of bombarding ions and neutrals. Comparison of the obtained sputter yields in Ar and Cl2 discharges with corresponding data from (chemically assisted) ion‐beam sputtering gives further insight into the etching mechanisms of Si, SiO2, Ti, and TiSi2.
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81.65.-b Surface treatments
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
52.40.Hf Plasma-material interactions; boundary layer effects
52.80.-s Electric discharges

Pump polarization effects in cw dye lasers

Lee W. Casperson, W. J. Sandle, A. C. Wilson, D. M. Warrington, and R. J. Ballagh

J. Appl. Phys. 69, 8005 (1991); http://dx.doi.org/10.1063/1.347496 (6 pages) | Cited 4 times

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The effects of pump polarization on the performance of cw dye lasers have been investigated. A recently developed semiclassical model for synchronously pumped mode‐locked dye lasers is adapted to the problem of cw dye‐laser oscillation, and analytic expressions are obtained for the relationship between the pump power, pump polarization, and dye‐laser output power. The theoretical results are compared with experimental data obtained using an argon‐laser‐pumped rhodamine 6G dye laser.
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42.55.Ah General laser theory
42.55.Mv Dye lasers
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Second‐order nonlinear optical properties and relaxation characteristics of poled linear epoxy polymers with tolane chromophores

D. Jungbauer, I. Teraoka, D. Y. Yoon, B. Reck, J. D. Swalen, R. Twieg, and C. G. Willson

J. Appl. Phys. 69, 8011 (1991); http://dx.doi.org/10.1063/1.347497 (7 pages) | Cited 30 times

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A new linear epoxy polymer containing 4‐amino‐4′‐nitrotolane chromophores attached to the chain backbone was synthesized in an attempt to enhance both the poling‐induced nonlinear optical susceptibility and its long‐term stability. The polymer films poled by corona discharge showed very large nonlinear optical doubling coefficients of d33 ≂ 89 pm/V and d31≂25 pm/V for incident light of 1.06 μm wavelength, and a linear electro‐optic coefficient r13≂8 pm/V at 633 nm wavelength. Poling‐induced alignment of the nonlinear optical moieties showed no detectable decay in two weeks at ambient temperature, as studied by the birefringence. Even at 100 °C the relaxation time estimated from the birefringence decay was ca. 450 h, consistent with roughly 16% decrease in dij coefficients in 20 h at this temperature and also the extrapolation from the dielectric α relaxation characteristics. The dielectric α relaxation temperatures of the poled polymer samples exhibited higher values than that of the unpoled counterpart. This unusual behavior may be due to a significant contribution of Maier–Saupe thermotropic interactions among the tolane moieties that favor parallel alignment.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
78.20.Jq Electro-optical effects
61.41.+e Polymers, elastomers, and plastics
77.22.Gm Dielectric loss and relaxation

Excitation of ultrasonic Lamb waves in piezoelectric plates

S. G. Joshi and Y. Jin

J. Appl. Phys. 69, 8018 (1991); http://dx.doi.org/10.1063/1.347498 (7 pages) | Cited 16 times

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The excitation of ultrasonic Lamb waves by an interdigital transducer (IDT) deposited on a piezoelectric plate is analyzed using the Green’s‐function method. The amplitudes of the generated Lamb waves are obtained in terms of the charge density on transducer electrodes. An electrostatic analysis that neglects piezoelectric coupling is used to relate this charge density to the voltage applied across the IDT. This is then used to calculate the radiation conductance of the transducer. Experimentally measured characteristics of interdigital transducers deposited on 128° Y‐X and Y‐Z lithium niobate plates are found to be in fair agreement with theoretical calculations. The analysis can also be used to calculate the electromechanical coupling between the IDT and various Lamb‐wave modes. It is found that when the plate is more than a few acoustic wavelengths thick, the lowest‐order symmetric and antisymmetric Lamb modes are almost equally generated. The slight difference in the velocities of these modes gives rise to the beating effect, whereby energy launched by the IDT on one surface transfers periodically back and forth between the two surfaces as a sinusoidal function of the distance traveled. A 65‐MHz Lamb‐wave delay line fabricated on a 0.25‐mm‐thick Y‐Z lithium niobate plate shows the beating effect, with a beat wavelength of 14.7 mm, in good agreement with theoretical calculations.
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43.38.Fx Piezoelectric and ferroelectric transducers
43.35.Pt Surface waves in solids and liquids
43.20.Bi Mathematical theory of wave propagation

Investigation of the thermal dissociation of PH3 and NH3 using quadrupole mass spectrometry

J. N. Baillargeon, K. Y. Cheng, S. L. Jackson, and G. E. Stillman

J. Appl. Phys. 69, 8025 (1991); http://dx.doi.org/10.1063/1.347447 (6 pages) | Cited 5 times

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The thermal dissociation of PH3 and NH3 injected through a Ta‐based high‐pressure gas‐injection cell were studied. Using a quadrupole mass spectrometer, the Ta was found to effectively dissociate the PH3 into primarily P2, P4, and H2 molecules with an injector temperature as low as 550 °C. The introduction of NH3 through this same injector resulted in dissociation into N2 and H2 for an injector temperature greater than 900 °C. When NH3 and PH3 were coinjected, again P2, P4, N2, and H2 were the primary molecules produced; however, an additional dimer, PN, was also detected. The PN concentration was maximum at a cell temperature of 700 °C. This dimer was found to be an effective source for introducing nitrogen as an isoelectronic trap in GaP.
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82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Movement of phase boundaries of metals subjected to surface periodic energy pulses

I. Yu. Smurov, A. A. Uglov, A. M. Lashin, P. Matteazzi, V. Tagliaferri, and L. Covelli

J. Appl. Phys. 69, 8031 (1991); http://dx.doi.org/10.1063/1.347448 (6 pages) | Cited 3 times

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The heat phenomena including heating, melting, evaporation, cooling, and solidification are analyzed by means of mathematical modeling. Velocities and positions of phase boundaries (both evaporation and melting) are determined for different conditions of pulse‐periodic energy flow irradiation of metallic materials. Heat process dynamics, determined by the shape of the single energy pulse, by the energy input per oscillation period, and by the average energy density flow, are discussed.
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81.40.Gh Other heat and thermomechanical treatments
81.30.Bx Phase diagrams of metals, alloys, and oxides

Mathematical model of internal temperature profile of GaAs during rapid thermal annealing

C. E. Third, F. Weinberg, and L. Young

J. Appl. Phys. 69, 8037 (1991); http://dx.doi.org/10.1063/1.347449 (5 pages) | Cited 2 times

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In previous studies it was reported that GaAs samples which were rapid thermal annealed exhibit bright bands adjacent to the surfaces in cathodoluminescence images of the cross sections. It is possible that the presence and depth of these bright bands are related to thermal stresses in the GaAs resulting from thermal gradients during heating and cooling. To investigate this possibility, a one‐dimensional mathematical model was developed to predict the temperatures through the thickness of the GaAs. Calculations of the thermal stress field show that the thermal stresses do not correlate with the depth of the bright bands.
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05.70.Ce Thermodynamic functions and equations of state
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization
65.90.+i Other topics in thermal properties of condensed matter (restricted to new topics in section 65)

Characterization of lubricated states on carbon coated media by low energy photoelectron spectroscopy method in ambient atmosphere

Ken‐ichi Nishimori, Kohichi Tanaka, and Yasunobu Inoue

J. Appl. Phys. 69, 8042 (1991); http://dx.doi.org/10.1063/1.347450 (5 pages) | Cited 1 time

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In this paper, we demonstrated the usefulness of low energy photoelectron spectrometer (LEPS) to characterize lubrication states on sputter carbon coated thin‐film disk. The threshold of photoelectric emission from lubricated sputter carbon, which was obtained by LEPS, gave significant information of the surface state on lubricated sputter carbon, and it explained the experimental results on the tribological behavior between the slider and lubricated disk. Furthermore, the thickness of the lubricant above 5 nm can be evaluated by measuring the attenuation of photoelectrons. It is applicable to the in situ measurement of photoelectric surface states of disk samples in ambient atmosphere without destroying them. This has a great advantage over the conventional photochemical analysis such as x‐ray photoelectron spectroscopy and Auger electron spectroscopy.
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79.60.Jv Interfaces; heterostructures; nanostructures
07.78.+s Electron, positron, and ion microscopes; electron diffractometers

A continuum model for low‐pressure radio‐frequency discharges

M. Meyyappan

J. Appl. Phys. 69, 8047 (1991); http://dx.doi.org/10.1063/1.347451 (5 pages) | Cited 16 times

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A computational model for low‐pressure (<0.3–0.5 Torr) radio‐frequency glow discharges is presented. The governing equations are the first three moments of the Boltzmann transport equations. In order to describe the weakly collisional sheaths, the nonlinear inertia terms in the momentum equations are retained. The model is demonstrated for a 13.56‐MHz argon discharge. A parametric study involving variations in pressure, electrode spacing, and driving voltage is presented.
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52.80.Hc Glow; corona
52.65.-y Plasma simulation
52.80.Tn Other gas discharges

A method for the phase measurement of the multipacting electrons

Majid T. Noori and Gerald S. Harmon

J. Appl. Phys. 69, 8052 (1991); http://dx.doi.org/10.1063/1.347452 (4 pages) | Cited 1 time

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At high frequency in a low pressure electrical discharge, multipacting electrons are believed to be responsible for the gas breakdown. The multipacting theory predicts that these electrons arrive at the end plate of the discharge tube while the phase of the rf field is within a particular range. Although there exist some indirect verification of phase pile‐up of multipacting electrons, it was felt that a direct measurement of the phase angle distribution was needed. A simple and practical method is presented in this paper for performing the task. This method was employed for such a measurement and the outcome is in a good agreement with the theoretical predictions.
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52.20.Fs Electron collisions
52.25.Jm Ionization of plasmas
51.50.+v Electrical properties (ionization, breakdown, electron and ion mobility, etc.)
52.25.Tx Emission, absorption, and scattering of particles

High‐dose neutron generation from plasma ion implantation

Han S. Uhm and W. M. Lee

J. Appl. Phys. 69, 8056 (1991); http://dx.doi.org/10.1063/1.347453 (8 pages) | Cited 5 times

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Based on a theoretical estimation, a simple new scheme to generate high‐dose, steady‐state neutrons is presented. This new high‐dose neutron source makes use of the plasma ion implantation, which consists of a cylindrical palladium rod saturated with deuterium atoms and immersed in a deuterium or tritium plasma. The plasma is contained by a grounded conducting chamber. The palladium rod is connected to a high‐power modulator, which provides a series of negative‐voltage pulses. During these negative pulses, deuterium or tritium ions fall into the palladium rod and collide with the deuterium atoms in it, initiating fusion reactions and emitting neutrons. This neutron device will be portable, reliable and almost free from radiation hazards except for the neutrons themselves. For reasonable system parameters allowed by present technology, we find from a theoretical calculation that the average neutron production rate 〈dN/dt〉 = 2.3 × 1012 s−1 for D‐T reaction, which may be more than enough for most applications. The average neutron production rate for D‐D reaction is two order of magnitude less than that for D‐T reaction.
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29.25.Dz Neutron sources
25.10.+s Nuclear reactions involving few-nucleon systems
52.75.-d Plasma devices

Ion extraction characteristics on a barium plasma produced between grounded parallel plate electrodes and a positively biased upper plate electrode

Kimio Yamada, Tsutomu Tetsuka, and Yoshihiro Deguchi

J. Appl. Phys. 69, 8064 (1991); http://dx.doi.org/10.1063/1.347454 (8 pages) | Cited 11 times

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When a barium plasma was suddenly produced between parallel plate electrodes and an upper plate electrode with a higher potential, the ion extraction was investigated in comparison with characteristics of the usual parallel plate electrode configuration. The parameter dependencies of ion extraction time by an external electric field, measured under a variety of experimental conditions, led to the conclusion that the ion extraction time can be expressed as the product of exponents of the applied voltage, plasma width, and ion density as well as the parallel plate electrodes. This scaling relation estimates the ion extraction time with an accuracy of 15% for a given parameter set. Comparison of the scaling relations for the new electrode concept with a highly biased upper plate electrode and the parallel plate electrodes showed that the former improves the ion extraction time by a maximum factor of 2.6.
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29.25.Lg Ion sources: polarized
29.25.Ni Ion sources: positive and negative
28.60.+s Isotope separation and enrichment

Investigation of Se+‐implanted GaAs layers by temperature‐dependent dechanneling

T. Bachmann, W. Wesch, K. Gärtner, and H. Bartsch

J. Appl. Phys. 69, 8072 (1991); http://dx.doi.org/10.1063/1.347455 (4 pages) | Cited 5 times

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Semi‐insulating GaAs wafers were implanted with 300‐keV Se+ ions, Ni=1×1014 cm−2, at different temperatures (300 to 513 K). Weakly damaged layers were produced in the case of implantation at elevated temperatures. Channeling measurements at different temperatures showed the existence of displaced lattice atoms with low distances ra from the string dominating. The influence of the damage present in the as‐implanted state on the resulting electrical sheet properties after annealing by means of a graphite strip heater is discussed.
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61.85.+p Channeling phenomena (blocking, energy loss, etc.)
61.72.U- Doping and impurity implantation
61.72.Bb Theories and models of crystal defects
73.61.Ey III-V semiconductors

Scanning tunneling microscopy of hexagonal BN grown on graphite

H. Fukumoto, T. Hamada, T. Endo, and Y. Osaka

J. Appl. Phys. 69, 8076 (1991); http://dx.doi.org/10.1063/1.347456 (3 pages)

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The microscopic surface topography of thin BNx films grown on graphite by electron cyclotron resonance plasma chemical vapor deposition have been imaged with scanning tunneling microscopy in air. The scanning tunneling microscope has generated images of hexagonal BN with atomic resolution.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
07.79.Cz Scanning tunneling microscopes
61.05.-a Techniques for structure determination
68.55.-a Thin film structure and morphology

Fourier transform infrared attenuated total reflection spectra of ion‐implanted silica glasses

Hideo Hosono

J. Appl. Phys. 69, 8079 (1991); http://dx.doi.org/10.1063/1.348925 (4 pages) | Cited 28 times

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Fourier transform infrared attenuated total reflection spectra of silica glasses implanted with Si or P were measured using a Ge as an internal reflection element. Calculated penetration depth of the infrared radiation is 0.2–1.0 μm depending on the wavelength. These values are comparable to the depths of ions implanted at conventional acceleration voltages. Upon implantation the frequencies of ω4(LO) and ω4(TO) shifted to lower energy, whereas ω3 moved to higher energy. This opposite direction of the frequency shift was explained by a decrease in the Si‐O‐Si bridging angle, which is caused by ion‐bombarded compaction. The magnitude of frequency shifts observed were much larger than that in thermally compacted silica glasses reported so far, showing that an extremely high fictive temperature state is realized in the implanted silica glass layers.
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42.70.Ce Glasses, quartz
61.72.up Other materials
78.35.+c Brillouin and Rayleigh scattering; other light scattering

Mechanisms of thermal stress relaxation and stress‐induced voiding in narrow aluminum‐based metallizations

M. A. Korhonen, C. A. Paszkiet, and Che‐Yu Li

J. Appl. Phys. 69, 8083 (1991); http://dx.doi.org/10.1063/1.347457 (9 pages) | Cited 64 times

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Thermal stress‐induced voiding in narrow aluminum‐based metallizations used as interconnects in microelectronic circuits has recently become a serious reliability concern. Room‐temperature stress relaxation and associated physical phenomena in passivated and unpassivated aluminum‐based metallizations, subsequent to exposure to high temperatures, are analyzed based both on theoretically estimated and experimentally determined thermal stresses. It is shown that stress relaxation at longer times involves mainly dislocation climb, while short‐term relaxation during cool down from higher temperatures, and immediately thereafter, involves significant dislocation glide. Void growth, frequently observed in passivated metallizations, provides a new source of atoms to feed stress relaxation by the same processes as in the absence of voiding.
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62.40.+i Anelasticity, internal friction, stress relaxation, and mechanical resonances
61.72.Lk Linear defects: dislocations, disclinations

Study of point defect clusters produced by BF+2 implantation in silicon single crystals

Krishan Lal, G. Bhagavannarayana, and G. S. Virdi

J. Appl. Phys. 69, 8092 (1991); http://dx.doi.org/10.1063/1.347458 (4 pages) | Cited 4 times

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High‐resolution diffuse x‐ray scattering (DXS) measurements made with a multicrystal x‐ray diffractometer have been used to characterize point defect clusters produced by 90‐keV and 135‐keV BF+2 implantations (fluence=1×1015 cm−2). The specimens were 50‐mm‐diam (100) silicon single crystals (n type; 4–6 Ω cm resistivity). A highly monochromated and collimated Kα1 is obtained by three‐plane (111) silicon single crystals oriented in (+,−,−) setting. The DXS intensity around 400 reciprocal lattice point was measured along [<sx>100<be>±] directions. Implantation produced a slight broadening of diffraction curves from ∼6 to ∼7 arcsec. From unimplanted regions diffuse scattering was primarily due to isolated interstitial point defects in the investigated volume of reciprocal space. Implantation was found to produce interstitial point defect clusters. Experimental data has been analyzed by using a phenomenological model for dislocation loops by using a curve fitting method. The values of loop size Rcl, volume of the loops Acl, and number of defects per loop Ncl have been determined. For implantation energies of 90 and 135 keV, these are, respectively, Rcl=1.47×10−4 and 1.29×10−4 cm, Acl=2.92×10−16 and 2.27×10−16 cm3, and Ncl=1.46×107 and 1.37×107.
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61.72.uf Ge and Si
61.72.J- Point defects and defect clusters
61.05.cf X-ray scattering (including small-angle scattering)
61.05.cj X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.

X‐ray diffraction from d spacing gradients along ion‐implanted zones

Satish I. Rao and C. R. Houska

J. Appl. Phys. 69, 8096 (1991); http://dx.doi.org/10.1063/1.347459 (8 pages) | Cited 2 times

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Three kinematic diffraction models are described for interpreting diffraction profiles from ion‐implanted samples. Each deals with relatively large d spacing gradients. The first treats the full zone as coherent which requires a direct summation of the Fourier series. The Bragg intensity band from the full zone is applied to implanted zones that are subjected to elastic constraints without incoherent interfaces. For high‐fluence samples, and foreign interstitials, a static attenuation term becomes important and is included in all models. This term was not included in previous publications by the authors. The last two models deal with finite subgrain elements that may be connected in a continuous way with interfaces. With a linear element model, slope discontinuities give a sawtooth appearance of the d spacing curve. These discontinuities are eliminated by employing a sinusoidal variation in d spacing in a third model. The additional smoothing does not provide significant changes in the fine structure of the measured intensity. The parameters that determine line shape are: ΔM, the total change in the attenuation factor M within a subgrain, and s = N3l(Δd/〈d〉) which contains three additional independent parameters. These are the subgrain size, the order of the Bragg peak l, and the fractional changes in d spacing. The static lattice displacements can be large enough to introduce an asymmetry of the diffraction profiles from individual elements. This occurs when ΔM is greater than 0.15. Although this factor has been introduced only into the linear element model, a similar asymmetry should be observed with a sinusoidal variation in d spacing.
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61.05.cc Theories of x-ray diffraction and scattering
61.72.jd Vacancies
61.72.jj Interstitials

X‐ray diffuse scattering from a nitrogen‐implanted niobium film

Satish I. Rao, C. R. Houska, K. Grabowski, G. Ice, and C. J. Sparks

J. Appl. Phys. 69, 8104 (1991); http://dx.doi.org/10.1063/1.347460 (7 pages) | Cited 5 times

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A 2500‐Å niobium single‐crystal film was deposited onto a sapphire substrate and subsequently implanted with nitrogen to an average concentration of 0.5 at. %. Synchrotron radiation was used to measure the difference between the implanted and an unimplanted film to isolate the diffuse scattering from the implanted film near two Bragg reflections. This diffuse intensity arises mainly from elastic displacement fields about radiation‐damage‐related loops located on (211) planes. A small contribution of the scattering is calculated from the displacements about single interstitial nitrogen in octahedral sites. The Burgers vector of the loops is along the [111] direction and makes an angle of 62° with the loop plane giving a dominant shear component. Vacancy loops have a radius ∼5 Å while interstitials are somewhat larger ranging from 10 to 15 Å. The number of vacancies and interstitials are nearly the same.
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61.05.cf X-ray scattering (including small-angle scattering)
61.05.cj X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.
61.72.jd Vacancies
61.72.jj Interstitials

X‐ray diffraction analysis of concentration and residual stress gradients in nitrogen‐implanted niobium and molybdenum

Satish I. Rao, Baoping He, C. R. Houska, and K. Grabowski

J. Appl. Phys. 69, 8111 (1991); http://dx.doi.org/10.1063/1.347461 (8 pages) | Cited 2 times

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Large biaxial residual strains are developed after a 5‐at.% implantation of N into Nb and Mo. The results indicate that the dominant source of internal strain arises from N located in interstitial sites. For Nb implanted at liquid‐nitrogen temperature, the N atoms are located in octahedral sites. However, the data allow for some clustering as di‐ or tri‐interstitials at the highest concentration (∼5 at. % N). Radiation damage is present as small vacancy and interstitial loops. Since vacancies and self‐interstitials are present in nearly equal concentrations, the overall bulk dilatation cancels. However, because of their small size, a lesser core expansion has been included as a correction to the overall residual strain. Although one can obtain an estimate of the N distribution from trim, a more accurate description must include the distribution of knock‐on energy. The latter has an important influence on the redistribution of N relative to that predicted by trim. Both host lattices (Nb and Mo) behave like ‘‘rigid containers’’ in directions parallel to the free surface and give a magnified elastic response normal to the free surface.
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61.05.cf X-ray scattering (including small-angle scattering)
61.05.cj X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.
61.72.jd Vacancies
61.72.jj Interstitials

Screened potential of a charged dislocation in piezoelectric semiconductors

K. Shintani

J. Appl. Phys. 69, 8119 (1991); http://dx.doi.org/10.1063/1.347462 (3 pages) | Cited 3 times

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A simplified model is proposed for analyzing the electric potential around a charged dislocation in piezoelectric semiconductors. In the analysis of the order of the Debye length, the solution for the piezoelectric potential screened by the carriers and ionized impurities is obtained. Consideration of the electrostatic potential field near the dislocation complete the determination of the solution. Numerical calculations of the potential are made for GaAs.
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61.72.Lk Linear defects: dislocations, disclinations
72.80.Ey III-V and II-VI semiconductors
77.65.-j Piezoelectricity and electromechanical effects

The thermal conductivity of isotopically enriched polycrystalline diamond films

T. R. Anthony, J. L. Fleischer, J. R. Olson, and David G. Cahill

J. Appl. Phys. 69, 8122 (1991); http://dx.doi.org/10.1063/1.347463 (4 pages) | Cited 28 times

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The thermal conductivity of a chemically vapor deposited (CVD) diamond film containing 0.07% 13C was measured as a function of temperature by ac and dc techniques and compared to CVD diamond with a natural isotopic abundance of 1.07% 13C. Unlike the single‐crystal case where a large isotope enhancement effect has been reported, no increase in the thermal conductivity was observed in isotopically enriched CVD diamond films. The absence of an isotope effect in CVD diamond films indicates that a phonon scattering mechanism other than isotope scattering dominates in CVD diamond.
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66.70.-f Nonelectronic thermal conduction and heat-pulse propagation in solids; thermal waves
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
63.20.kp Phonon-defect interactions

Li and Sb doping effects on the growth behavior of ZnS on GaP substrates

Shunro Fuke, Yoshihide Sugihara, Chikako Maezawa, Kazuhiro Kuwahara, and Tetsuji Imai

J. Appl. Phys. 69, 8126 (1991); http://dx.doi.org/10.1063/1.347464 (4 pages)

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The effects of impurities (Li and Sb) introduced into the carrier gas on the growth rate and crystallinity are investigated for the vapor‐phase epitaxial growth of ZnS on GaP substrates. In the case of Sb incorporation, a clear dependence of the growth rate on polar planes has not been obtained. On the other hand, Li incorporation to the growth ambient causes an increase of the growth rate on (111)A plane and a decrease on (111)B plane. This result is analogous to that observed in case of In doping and is in contrast with the iodine doping effects. These impurity effects are found to depend on the combination between the ionization polarity of impurity elements and the polarity of the substrate orientation.
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81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.10.Bk Growth from vapor
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
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