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1 Nov 1993

Volume 74, Issue 9, pp. R83-5920

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Dimensional metrology with scanning probe microscopes

Joseph E. Griffith and David A. Grigg

J. Appl. Phys. 74, R83 (1993); http://dx.doi.org/10.1063/1.354175 (27 pages) | Cited 37 times

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We review the application of scanning probe microscopes to dimensional measurement of topographic features. Probe microscopes show great promise as metrology tools because they produce three‐dimensional data over almost all solids in a wide range of ambients. Even though these microscopes readily achieve atomic resolution, there are several aspects of their behavior that can cause them to exhibit large measurement errors. The actuators that drive the probe exhibit hysteresis and creep, so they must be independently monitored. In addition, the geometry of an extended probe moving across the surface makes probe‐sample interaction intrinsically nonlinear. Forces on the probe that cause it to flex are another source of inaccuracy. Probe fabrication and characterization are, consequently, important issues. We describe present understanding of these problems and the techniques being developed to solve them.
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07.78.+s Electron, positron, and ion microscopes; electron diffractometers
07.60.Pb Conventional optical microscopes
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy
06.20.-f Metrology

Performance characteristics of endoreversible chemical engines

J. M. Gordon and Vladimir N. Orlov

J. Appl. Phys. 74, 5303 (1993); http://dx.doi.org/10.1063/1.354253 (7 pages) | Cited 29 times

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Chemical engines process mass flows to convert differences in chemical potential into work—the analog of heat engines processing heat flows to generate work from temperature differences. For isothermal endoreversible chemical engines constrained to finite‐time operation—examples of which include mass exchangers, electrochemical, photochemical, and solid‐state devices: (i) optimal cycle types for maximizing average power output, (ii) upper bounds on power production, and (iii) sensitivity of these results to mass‐transfer law, illustrated for linear and diffusive behavior, are derived.
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05.70.-a Thermodynamics
82.60.-s Chemical thermodynamics
84.60.-h Direct energy conversion and storage

On optimizing maximum efficiency of finite‐time engines

Fredy Romm

J. Appl. Phys. 74, 5310 (1993); http://dx.doi.org/10.1063/1.354231 (4 pages) | Cited 2 times

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The literature data about finite‐time engines have been reviewed. We have shown that the modern technical thermodynamics largely use the finite‐time engines concept. We use the apparatus of finite‐time thermodynamics to describe a stationary engine—assemblage of multiple thermodynamically identical nonstationary engines working at a fixed phase difference. The author proposes a new model which considers an assemblage of thermodynamically identical engines functioning at different phases. The assemblage is itself a stationary engine. The model allows one to evaluate the internal energy dissipation caused by interaction of the elementary engines that is equivalent to the influence of the environment. We obtained the equations describing the system considered and found the conditions for maximum efficiency.
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05.70.Ln Nonequilibrium and irreversible thermodynamics
05.70.-a Thermodynamics

Computational complexity and the observation of physical signals

Caesar Saloma

J. Appl. Phys. 74, 5314 (1993); http://dx.doi.org/10.1063/1.354232 (6 pages) | Cited 7 times

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The effects of computational complexity on the characteristics of a physical signal that is reconstructed from its representation of sampled data are analyzed. It is found that a more complex algorithm does not only require longer time to implement, but also yields an erroneous reconstruction. The reconstruction suffers from contrast degradation, phase shifts, and attenuation of details relative to the true signal. These unwanted effects are caused by the existence of spurious frequencies in the computed spectrum due to rounding‐off errors. The amplitude distribution of the spurious frequencies across the spectral bandwidth strongly depends on the number of data points handled and on the complexity of the particular reconstruction algorithm employed. Since the floating point representation of numbers in a computer is always finite, an upper limit exists in the maximum number of additions or multiplications required to compute a quantity reliably without errors.
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07.05.Hd Data acquisition: hardware and software
07.05.Kf Data analysis: algorithms and implementation; data management
07.05.Rm Data presentation and visualization: algorithms and implementation
89.20.Ff Computer science and technology
02.60.-x Numerical approximation and analysis

Surface roughness effects on cylindrical grazing incidence x‐ray optics for transition radiation

A. H. Ho, M. A. Piestrup, R. M. Silzer, and D. M. Skopik

J. Appl. Phys. 74, 5320 (1993); http://dx.doi.org/10.1063/1.354233 (7 pages) | Cited 1 time

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Quartz and nickel cylinders were used as grazing incidence x‐ray optics for transition radiation (TR) from Al, Ti, and Cu foil stacks. The cylinders were used to direct the otherwise diverging TR to a small spot (1 mm diameter), with measured fluxes of up to 330 W/A cm2 averaged over the spot area. Computer simulations were performed and compared to the measured results. It was found that including surface roughness effects in the form of a Debye–Waller reduction factor on the reflectivity was necessary to get good agreement between the simulations and experimental results in certain cases, but not in others. A simple heuristic model which can be used to determine when roughness effects are important is presented. Use of this model in conjunction with the computer simulations accurately predicts the measured results, and further suggests the use of different optic materials at different x‐ray wavelengths.
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07.85.-m X- and γ-ray instruments
42.79.Bh Lenses, prisms and mirrors

Chemical model for wire chamber aging in CF4/iC4H10 gases

J. Wise, J. A. Kadyk, and D. W. Hess

J. Appl. Phys. 74, 5327 (1993); http://dx.doi.org/10.1063/1.354234 (14 pages) | Cited 1 time

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Aging of proportional counters in CF4/iC4H10 mixtures is studied as a function of gas composition. Anode surfaces are analyzed by Auger electron spectroscopy. Anode‐wire deposits are formed from 95/5 and 90/10 mixtures of CF4/iC4H10; etching of deposits occurs in 50/50 and 80/20 mixtures of CF4/iC4H10 and in pure CF4. Gold‐plated wires are resistant to aging resulting from chemical attack by CF4, but non‐gold‐plated wires are too reactive for use in CF4‐containing gases. An apparent cathode aging process resulting in loss of gain rather than in a self‐sustained discharge current is observed in CF4 and CF4‐rich gases. Principles of low‐pressure rf plasma chemistry are used to interpret the plasma chemistry in avalanches (≥1 atm, dc). To understand anode aging in CF4/iC4H10 gases, a four‐part model is developed considering: (i) plasma polymerization of iC4H10; (ii) etching of wire deposits by CF4; (iii) deposition that occurs as a result of radical scavenging in strongly etching environments; and (iv) reactivity of the wire surface. Practical guidelines suggested by the model and application of the model to other fluorine‐containing gases are discussed.
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29.40.Cs Gas-filled counters: ionization chambers, proportional, and avalanche counters
81.05.Bx Metals, semimetals, and alloys
52.80.Tn Other gas discharges

Multi‐beam laser deflection measurements of reduced density channels created by electron beams propagating in near‐atmospheric‐pressure air

K. R. Stalder, M. S. Williams, and D. J. Eckstrom

J. Appl. Phys. 74, 5341 (1993); http://dx.doi.org/10.1063/1.354235 (8 pages) | Cited 3 times

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Properties of reduced density channels created by energy deposition from electron beams propagating in air are presented. A multi‐beam laser deflection technique used to diagnose the channels is described, as are representative examples of density channels formed in multi‐pulse propagation experiments performed at the Advanced Test Accelerator at the Lawrence Livermore National Laboratory.
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41.75.Ht Relativistic electron and positron beams
42.62.-b Laser applications

Exciton photoluminescence of quantum wells affected by thermal migration and inherent interface fluctuation

Er‐Xuan Ping and Vikram Dalal

J. Appl. Phys. 74, 5349 (1993); http://dx.doi.org/10.1063/1.354236 (5 pages) | Cited 6 times

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Exciton photoluminescence (PL) of quantum wells (QW), affected by the thermal migration and the inherent interface roughness, has been studied by a model which includes exciton transfer between the growth islands with one atomic layer difference in well thickness. Analytical expressions, showing a red shifting and linewidth changing compared to the exciton PL spectra without thermal migration, are obtained. At low temperature, the red shifting and the linewidth changing are uniquely determined by the geometry of the QW. At high temperature, the red shift and the linewidth changing depends on the temperature, structure, and inherent interface fluctuation of the QW. Under the influence of the thermal migration, the inconsistency of the PL and PL excitation spectra has been reexamined and quantitatively obtained as a function of the temperature, quality, and structure of the QW.
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78.66.-w Optical properties of specific thin films
71.35.-y Excitons and related phenomena

Angular distribution of the sputtered atoms from TbFeCo targets

Shiuh Chao, Tzuan‐Ren Jeng, Vien‐Shien Lo, Der‐Ray Huang, and Tsai‐Chu Hsiao

J. Appl. Phys. 74, 5354 (1993); http://dx.doi.org/10.1063/1.354237 (6 pages) | Cited 2 times

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The angular distribution of the sputtered Tb, Fe, and Co atoms from the elemental targets could be described by cosn θ distribution with n=1.90, 0.54, and 1.01 for Tb, Fe, and Co, respectively. For TbFeCo composite targets with mixed elemental and intermetallic compound phases, the overall angular distribution of the sputtered Tb, Fe, and Co atoms from the mixed phases could also be described by the cosn θ distribution function, and the values of the n’s were related to the volume percentage of the intermetallic compound content in the composite target. This was not true of the Tb distribution for a target containing high intermetallic compound content. In that sample, an off‐normal term has to be added to the cosn θ distribution function. It was found that a composite target with about 23 vol % intermetallic compound would produce a uniform composition distribution of TbFeCo film on the substrate.
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81.15.Cd Deposition by sputtering
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
85.70.Kh Magnetic thin film devices: magnetic heads (magnetoresistive, inductive, etc.); domain-motion devices, etc.

Dynamics of the detonation products of lead azide. IV. Laser shadowgraphy of expanding species

Y. Tzuk, I. Bar, and S. Rosenwaks

J. Appl. Phys. 74, 5360 (1993); http://dx.doi.org/10.1063/1.354238 (6 pages) | Cited 1 time

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Laser resonant shadowgraphy (LRS) and laser nonresonant shadowgraphy (LNRS) are used to monitor the detonation products of lead azide. Photographs of the cloud of products are obtained via illumination with a doubled dye laser tuned on‐resonance to the 3P1o‐3P0 transition of the Pb atom at 283.31 nm, and off‐resonance at 284.31 nm. The versatility of the diagnostics and its applicability to detonation products expanding into vacuum and into atmospheric pressure air are demonstrated. The LRS monitors the density gradients of both lead atoms and solid particles formed in the detonation, whereas the LNRS detects only the latter. Expansion into vacuum through a nozzle leads to an increase in the velocity (from ∼4.5 to ≳5 km/s) and density of the atoms and to a decrease in the density of the particles. The LRS measurements show that the expansion of both products in air is relatively slow (∼0.75 km/s) and leads to production of shock waves. From the shape of the shock waves created by an obstacle when the products expand into vacuum, the Mach number is estimated to be ≳20 in the outer parts and around 3 in the inner parts of the cloud.
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47.40.-x Compressible flows; shock waves

Processes in the prebreakdown stage of a low‐pressure discharge and the mechanism of discharge initiation in pseudospark switches

A. V. Kozyrev, Yu. D. Korolev, V. G. Rabotkin, and I. A. Shemyakin

J. Appl. Phys. 74, 5366 (1993); http://dx.doi.org/10.1063/1.354239 (6 pages) | Cited 9 times

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A time‐dependent model for the rapid current rise during initiation of the discharge in a pseudospark switch is presented. The following assumptions are made: (1) the gas is ionized only by electrons that originate at the cathode; (2) the cathode emissivity is infinite; (3) the average ionization cross section is constant; (4) the ion charge density is independent of gap position. The results are in qualitative agreement with a previous experimental study of a nitrogen‐filled switch operating between 6 and 20 kV for a range of gas pressures. The model provides a straightforward approach for estimating pseudospark breakdown times.
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52.75.Kq Plasma switches (e.g., spark gaps)
52.80.Mg Arcs; sparks; lightning; atmospheric electricity

Strong Kα emission in picosecond laser‐plasma interactions

B. Soom, H. Chen, Y. Fisher, and D. D. Meyerhofer

J. Appl. Phys. 74, 5372 (1993); http://dx.doi.org/10.1063/1.354240 (6 pages) | Cited 19 times

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Kα emission is observed from the interaction of a picosecond, 1.05 μm laser pulse at 4×1015 W/cm2 with a silicon target coated with various thicknesses of aluminum. Strong Kα emission requires a p‐polarized, high‐intensity‐contrast laser pulse. At 7.1 Å, the Kα yield is 1.5×108 photons/sr with a duration of emission of ≤8 ps and a source area of 1.6×10−6 cm2. The radiance is ≥3×109 W/cm2 sr. Monte Carlo simulations have suggested that under these conditions Kα emission is a promising candidate for an efficient, ultra‐short‐duration x‐ray source at ∼1.5 Å.
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52.50.Jm Plasma production and heating by laser beams (laser-foil, laser-cluster, etc.)
52.25.Os Emission, absorption, and scattering of electromagnetic radiation
52.75.-d Plasma devices

Plasma remediation of trichloroethylene in silent discharge plasmas

Diane Evans, Louis A. Rosocha, Graydon K. Anderson, John J. Coogan, and Mark J. Kushner

J. Appl. Phys. 74, 5378 (1993); http://dx.doi.org/10.1063/1.354241 (9 pages) | Cited 67 times

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Plasma destruction of toxins, and volatile organic compounds in particular, from gas streams is receiving increased attention as an energy efficient means to remediate those compounds. In this regard, remediation of trichloroethylene (TCE) in silent discharge plasmas has been experimentally and theoretically investigated. We found that TCE can be removed from Ar/O2 gas streams at atmospheric pressure with an energy efficiency of 15–20 ppm/(mJ/cm3), or 2–3 kW h kg−1. The majority of the Cl from TCE is converted to HCl, Cl2, and COCl2, which can be removed from the gas stream by a water bubbler. The destruction efficiency of TCE is smaller in humid mixtures compared to dry mixtures due to interception of reactive intermediates by OH radicals.
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52.80.-s Electric discharges
82.33.Xj Plasma reactions (including flowing afterglow and electric discharges)
52.75.-d Plasma devices

Microwave production by an intense ion beam propagating through a magnetized background plasma

R. Kraft and B. R. Kusse

J. Appl. Phys. 74, 5387 (1993); http://dx.doi.org/10.1063/1.354242 (4 pages)

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Measurements of the microwave radiation produced when an intense pulsed ion beam propagated from a field‐free region into a magnetized plasma are presented. The ion beam was initially charge and current neutralized by a comoving electron population. Upon entering the magnetized plasma, some of the neutralizing electrons were stripped from the ion beam by the magnetic field and replaced by plasma electrons which were accelerated to high velocities by a space‐charge imbalance within the ion beam. Electron plasma waves at the background plasma frequency were driven unstable by the high‐velocity plasma electrons.
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52.40.Mj Particle beam interactions in plasmas
52.35.Qz Microinstabilities (ion-acoustic, two-stream, loss-cone, beam-plasma, drift, ion- or electron-cyclotron, etc.)

Correlation between stress voiding of Al(Si)(Cu) metallizations and crystal orientation of aluminum grains

S. Kordić, R. A. M. Wolters, and K. Z. Troost

J. Appl. Phys. 74, 5391 (1993); http://dx.doi.org/10.1063/1.354243 (4 pages) | Cited 5 times

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The stress voiding behavior of Al(Si)(Cu) alloys has been investigated. The grain structure of the metal lines has been analyzed using the electron backscatter diffraction technique in a scanning electron microscope. A [111] fiber texture of aluminum has been observed perpendicular to the wafer surface. A correlation has been found between a high density of voids and the amount of misalignment of the [111] grain directions with respect to the wafer normal.  
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61.72.Qq Microscopic defects (voids, inclusions, etc.)
68.60.Bs Mechanical and acoustical properties
85.40.Ls Metallization, contacts, interconnects; device isolation

Deposition and device application of in situ boron‐doped polycrystalline SiGe films grown at low temperatures

Horng‐Chih Lin, Tze‐Guei Jung, Hsiao‐Yi Lin, Chun‐Yen Chang, Tan‐Fu Lei, P. J. Wang, Ray‐Chern Deng, Jandel Lin, and Chih‐Yeh Chao

J. Appl. Phys. 74, 5395 (1993); http://dx.doi.org/10.1063/1.354244 (7 pages) | Cited 16 times

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Deposition of in situ boron‐doped polycrystalline silicon‐germanium (poly‐Si1−xGex) films at temperatures below 550 °C was investigated using an ultrahigh‐vacuum chemical‐ vapor‐deposition system. These films with a fine grain structure were obtained for boron concentrations higher than 1021 cm−3. It is attributed to the enhanced nonequilibrium doping effect due to the addition of GeH4 gas during film deposition. Poly‐Si0.56Ge0.44 films with a carrier concentration of 8×1020 cm−3 were achieved at a growth temperature of 500 °C. Such a high activated carrier concentration resulted in a film resistivity less than 2 mΩ cm. Utilizing these characteristics, a novel approach was proposed and demonstrated to fabricate p‐channel polycrystalline silicon thin‐film transistors at process temperatures below 550 °C. These transistors with a maximum field effect mobility up to 28 cm2/V s and an on/off current ratio over 106 were achieved without employing any post‐treatment step, indicating the feasibility of this approach on the fabrication of polycrystalline silicon thin‐film transistors at low temperatures.
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68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
85.30.-z Semiconductor devices

Physical damage in silicon formed by helicon wave plasma etching

Tsutomu Tsukada, Hiroshi Nogami, Jun Hayashi, Kazu Kawaguchi, and Tohru Hara

J. Appl. Phys. 74, 5402 (1993); http://dx.doi.org/10.1063/1.354245 (4 pages) | Cited 2 times

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Damage formed on silicon by helicon wave oxygen plasma is studied. The damage density decreases from 1.9×1016 to 9.3×1015/cm2 with an increase of helicon wave power from 0.5 to 2.0 kW in the exposure for 5 min at a rf bias power density of 0.45 W/cm2 at 1.6 MHz. This decrease is mainly due to the rapid decrease of self‐bias voltage Vdc, with these power and ion current increases. This damage density variation is much different from those in other kinds of etching, such as, in an electron cyclotron resonance plasma etching. However, the damage density increases with a bias power increase. Lower damage etching, therefore, can be achieved when high helicon wave and low bias powers are supplied.
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61.80.-x Physical radiation effects, radiation damage
81.65.-b Surface treatments
52.40.Hf Plasma-material interactions; boundary layer effects

Study of defects in silicon dioxide films on Si(100) by a variable‐energy positron beam

M. Fujinami, N. B. Chilton, K. Ishii, and Y. Ohki

J. Appl. Phys. 74, 5406 (1993); http://dx.doi.org/10.1063/1.354246 (4 pages) | Cited 5 times

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Amorphous SiO2 films grown by both thermal oxidation and plasma chemical vapor deposition (CVD) in a tetraethylorthosilicate and O2 atmosphere were studied using variable‐energy positron annihilation spectroscopy and infrared (IR) spectroscopy. For thermally grown SiO2 layers with growth temperatures of over 1000 °C it was found that the measured Doppler broadening parameter was identical for both wet and dry growth atmospheres. The measured Doppler broadening parameter in the case of SiO2 prepared by plasma CVD was found to be strongly influenced by the substrate temperature during deposition. For a substrate growth temperature of 600 °C, the data are essentially identical to those of the thermally grown oxide layers. IR analysis revealed that the concentration of Si–OH in the SiO2 layer is affected by the substrate temperature during growth. The level of the Doppler broadening parameter in the SiO2 film exhibited changes that can be correlated with this Si–OH concentration. We thus show that the concentration of Si–OH in amorphous SiO2 film is a factor that may affect the Doppler broadening parameter.
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78.70.Bj Positron annihilation
78.35.+c Brillouin and Rayleigh scattering; other light scattering
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

The specific volumes of Pd40Ni40P20 in the liquid, glass, and crystallized states

K. C. Chow, S. Wong, and H. W. Kui

J. Appl. Phys. 74, 5410 (1993); http://dx.doi.org/10.1063/1.355286 (5 pages) | Cited 12 times

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The specific volumes of Pd40Ni40P20 were measured in the liquid, glass, and crystallized states. It was found that in the molten state, for temperatures below ∼1000 K, the specific volume measurement was successful only if the specimens were properly purified. Such purification could be achieved by fluxing the molten specimen in dehydrated boron oxide. Relaxation effects are observed and they manifested themselves in the variation of the thermal expansion coefficient with the quenching rates of the glassy specimens. The intersection points of the specific volume curves of the liquid (both stable and metastable), glass and crystallized are 573±80 and 492±80 K (extrapolated values), respectively. The former agrees very well with the glass transition temperature 577 K, obtained by the calorimetry method, while the latter implies that the melt, in accord with free volume theory, will have collapsed to the glass before that temperature is reached.  
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61.43.Fs Glasses
65.40.De Thermal expansion; thermomechanical effects

Mechanism for the formation of 90° dislocations in high‐mismatch (100) semiconductor strained‐layer systems

T. J. Gosling

J. Appl. Phys. 74, 5415 (1993); http://dx.doi.org/10.1063/1.354247 (6 pages) | Cited 17 times

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A rigorous calculation, within the framework of linear continuum elasticity, is performed to evaluate the energy of a rectangular 1/2[101](111) 60° dislocation glide loop nucleated at the site of a pre‐existing 1/2[110](111) 60° dislocation at the (100) interface between a strained epitaxial layer and its substrate. This nucleation event gives rise to an interfacial segment of 1/2[011](100) 90° dislocation, which extends as the glide loop expands. The presence of the pre‐existing 60° dislocation is found to reduce dramatically the energy of the loop relative to the energy of a comparable isolated loop. Results obtained for the elastic energy barrier to formation of such a loop for varying mismatch strain are incorporated into kinetic rate equations available in the literature. It is thus demonstrated that the mechanism of 90° dislocation formation described is expected to become experimentally significant at mismatch strains of around 2%. This result is in excellent agreement with the experimentally determined mismatch strain threshold at which significant 90° dislocation formation is observed to commence in GexSi1−x/Si(100) and InxGa1−xAs/GaAs(100) strained‐layer heterosystems.
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61.72.Lk Linear defects: dislocations, disclinations
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

A microstructural study of porous silicon

I. Berbezier and A. Halimaoui

J. Appl. Phys. 74, 5421 (1993); http://dx.doi.org/10.1063/1.354248 (5 pages) | Cited 36 times

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Porous silicon (PS) films obtained from lightly and heavily doped p‐type silicon have been investigated by transmission electron microscopy. Silicon crystallites with nanometric dimensions have been evidenced in both types of porous silicon layers. High resolution observations revealed lattice disorder even for low‐porosity (65%) samples. Concerning PS layers obtained from lightly doped substrates, it is shown that increasing porosity leads to a crystallite size reduction and to the deterioration of the material crystallinity. When the porosity is increased up to a value of about 85%, silicon crystallites with a mean diameter of less than 3 nm and an amorphous phase are clearly imaged.
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68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.37.Lp Transmission electron microscopy (TEM)
68.55.-a Thin film structure and morphology
61.43.-j Disordered solids

Detection of local conductivity by laser‐frequency mixing in a scanning force microscope

M. Völcker, W. Krieger, and H. Walther

J. Appl. Phys. 74, 5426 (1993); http://dx.doi.org/10.1063/1.354249 (6 pages) | Cited 8 times

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Coupling of laser radiation into a conducting tip of a scanning force microscope allows one to distinguish between conducting and nonconducting parts of a sample. This is demonstrated for a pattern of small metal islands on a nonconducting BaF2 substrate. In the experiment two infrared laser beams are coupled into the tip. The difference frequency is generated in the tip‐sample junction, emitted, and detected by means of an open waveguide. Images with this signal are recorded simultaneously with the topography. Difference‐frequency generation is observed only on conducting parts of the surface and at islands larger than about 1 μm in diameter. The size of the conducting island as well as the tunneling distance between the tip and conducting surface determine the magnitude of the difference‐frequency signal. Frequency mixing of visible laser light, using the excitation of localized plasmons for field enhancement, may lead to the detection of local conductivity on much smaller structures.
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68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy
73.61.-r Electrical properties of specific thin films
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation

X‐ray damage to optical components using a laser‐plasma source

R. C. Elton, D.‐M. Billings, J. Grun, F. C. Young, C. K. Manka, B. H. Ripin, H. R. Burris, J. Resnick, D. J. Ripin, and J. R. Millard

J. Appl. Phys. 74, 5432 (1993); http://dx.doi.org/10.1063/1.354250 (5 pages) | Cited 5 times

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X‐ray damage to optical surfaces consisting of melting, fracturing, cracking, and cratering is produced, and then analyzed using interference contrast microscopy and stylus profilometery. The test samples are irradiated by 0.5–1.6 keV x rays at fluence levels up to 5.5 cal/cm2. The x rays originate from L‐shell transitions in copper ions, produced when 1.25‐μm‐thick targets are irradiated at 1.3 kJ energy by a 1.054 μm wavelength laser. The x‐ray emission is found to be nearly isotropic over 2π sr, while the plasma mass‐flow distribution is peaked along the laser axis. Hence, contamination of the test sample by target debris or plasma is greatly reduced by placing the samples off axis from the laser beam, in addition to the use of beryllium shields.
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61.80.Cb X-ray effects
42.88.+h Environmental and radiation effects on optical elements, devices, and systems

Morphology and growth process of thermally induced oxide precipitates in Czochralski silicon

K. Sueoka, N. Ikeda, T. Yamamoto, and S. Kobayashi

J. Appl. Phys. 74, 5437 (1993); http://dx.doi.org/10.1063/1.354254 (8 pages) | Cited 28 times

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The morphology and growth process of oxide precipitates in Czochralski silicon have been studied with prolonged thermal treatments up to 700 h at intermediate temperatures (700–900 °C). It was found with transmission electron microscopy observation that (i) the morphology of precipitates changes from platelet to aggregation of polyhedra at both 800 and 900 °C during isothermal heat treatment, and (ii) the growth of platelet precipitates follows a t1/2 law.
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61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
61.72.Qq Microscopic defects (voids, inclusions, etc.)

Constraints on effective volumes assigned to atoms in ion implantation calculations

R. Collins

J. Appl. Phys. 74, 5445 (1993); http://dx.doi.org/10.1063/1.354255 (6 pages) | Cited 3 times

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Most calculations of atomic depth distributions in solids produced by high‐speed ion bombardment use the concept of the effective displacement volume Ωk of an atom of species k in a multicomponent system. General equations are given here to calculate the set {Ωk} from density‐composition data. It is further shown that if the {Ωk} vary with local composition, then these variations cannot be independent, but must satisfy equations of constraint, which are derived here. The case of a binary system is considered in more detail.
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61.72.S- Impurities in crystals
61.80.Jh Ion radiation effects
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