bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid Annealing of GaAs: Uniformity and Temperature Dependence of Activation
Authors: Cummings K. D. , Pearton S. J. , Vella-Coleiro G. P. 
Published: March 2011

ABSTRACTScanning microwave photoconductance, capacitance-voltage profiling and Hall effect measurements were used to investigate the uniformity of activation of Si, Be and Mg implanted 2″ and 3″ diameter, semi-insulating GaAs substrates after rapid thermal annealing in a commercial furnace. The results indicate that carrier lifetimes and mobilities for low dose (3−4 × 1012 cm−2) implants and carrier densities for high dose (1× 1015 cm−2) implants are comparable or superior in rapidly annealed substrates to those obtained in thermally annealed implanted layers. The uniformity of these parameters is not significantly different for wafers annealed by either method. The temperature dependence of damage removal and carrier activation in the implanted regions during both furnace and transient annealing was also investigated, and demonstrates that the microwave photoconductance technique gives results for donor implantation correlating well with conventional backscattering and electrical measurements respectively.
Rapid Themal Annealing of Shallow. Diffused Contact Regions in GaAs
Authors: Kepler N. J. , Cheung N. W. , Chu P. K. 
Published: March 2011

ABSTRACTRapid thermal annealing (RTA) is used to form shallow and heavily-doped contact regions in undoped, semi-insulating GaAs. These layers are formed by using a high-intensity tungstenhalogen lamp to diffuse germanium and selenium from a deposited GeSe thin-film. RTA reduces surface degradation and permits better control of the diffusion profile than conventional furnace annealing. Optimal 20-second RTA occurs above a diffusion threshold at 950°C but below the failure of the SiO2 encapsulant at 1100°C. The n+ regions created have peak impurity concentrations over 1020/cm3 at depths under 750 Å with sheet resistances less than 60 Ω/▩. Non-alloyed ohmic contacts exhibit specific contact resistivites of 2.2 × 10−4 Ω · cm−2.
Rapid Thermal Processing: A Bibliography
Authors: Powell R. A. , Manion M. L. 
Published: March 2011

ABSTRACTThis bibliography presents 342 references to work published on rapid thermal processing (RTP) from 1979 through mid-1985. A variety of broad-beam energy sources are represented, including: arc and quartz-halogen lamps, blackbody radiators, strip heaters, broadly rastered electron beams, and defocused CO2 lasers. Citations were obtained by both manual searching and searching of a commercially available computerized data base (I NSPEC). Entries are grouped under 13 topical headings: reviews, implanted dopant activation and diffusion in silicon, polycrystalline silicon, silicides and polycides, metals, dielectrics, compound semiconductors, defects and microstructure, device applications (silicon and compound semiconductors), miscellaneous applications, equipment, and modeling. Within each group, citations are arranged alphabetically by title. A full author index is provided.
Study of “Reverse Annealing” of Boron Under Low Temperature Lamp Anneals
Authors: Huang J. , Jaccodine R. J. 
Published: March 2011

ABSTRACTThe reverse annealing of ion implanted boron, namely, the decrease in the concentration of electrically active boron as the isochronal annealing temperature increases, occurs in the temperature range from 550 to 650°C during conventional furnace heating. In this study, silicon crystals were boron implanted at 50 Kev to a dose of 1×1015 cm-2 followed by both furnace and tungsten-halogen lamp annealing in the reverse annealing temperature range. Cross-sectional Transmission electron microscopic (TEM) technique was used to examine the microstructural changes during annealing as a function of depth. Sheet resistance measurements gave a quick check of the electrical properties, while spreading resistance profiling with shallow angle lapping and Hall measurements reveals the mobility and carrier concentration as a function of depth. Czochralski and Float Zone crystals were studied to examine the effect of oxygen. Tungsten-halogen lamp thermal processing was found to have a more pronounced effect on the annealing of secondary defects than did furnace annealing. The reverse annealing of boron was eliminated completely for lamp annealing time as short as 60 seconds.
Diffusion and Activation During Rapid Thermal Annealing of Implanted Boron in Silicon
Authors: Cowern N E B , Yallup K J , Godfrey D J , Hasko D G , McMahon R A , Ahmed H , Stobbs W M , McPhail D S 
Published: March 2011

ABSTRACTThe diffusion and activation of implanted boron in silicon during rapid thermal annealing (RTA) has been studied using the analytical techniques of SIMS, TEM, and sheet resistance measurements. Both crystalline and pre-amorphised silicon substrates were investigated. Data analysis in conjunction with a range of numerical models indicates some novel features of boron RTA, as well as accounting for previously observed features. In particular, a large transient diffusion enhancement coupled with an increase of electrical activity, are seen at short anneal times, in the case of crystalline silicon substrates. A non-equilibrium diffusion enhancement of a different type is also seen at much longer times, in both crystalline and pre-amorphised samples implanted to high doses. This second enhancement persists after all the precipitated boron formed on implantation has become substitutional. TEM studies show that the transient enhancement may be associated with the evolution of extended defect structures during the early stages of annealing. Both types of enhancement can be well represented by multiplying the ‘normal’ concentration-dependent diffusivity (with β=0.5) by a factor f>1.
A Simple, Non-Destructive Optical Technique to Characterize Ion-Implanted Semiconductor Wafers
Authors: Young Jeff F. , Jensen H. R. , Simard-Normandin Martine 
Published: March 2011

ABSTRACTA simple, non-destructive technique to characterize the properties of ion-implanted semiconductor wafers is described. The method consists of measuring the infrared attenuated total reflection (ATR) spectrum of the implanted layer/air interface and fitting it with a calculated spectrum which takes account of the free carrier density profile and any possible residual damage and/or amorphization. The results obtained on boron and implanted Si wafers, annealed at different temperatures in a rapid thermal annealer, are compared with their respective SIMS profiles.
GROWTH AND CHARACTERIZATION OF Hg1−xCdxTe ON CdTe SUBSTRATES, PREPARED BY ORGANOMETALLIC EPITAXY
Authors: Bhat I. B. , Ghandhi S. K. 
Published: March 2011

AbstractHgl−xCdxTe layers have been grown on CdTe substrates using dimethylcadmium, diethyltelluride and mercury in a horizontal reactor. Details of conditions for growth of these layers are presented in this paper. Specular surfaces of Hg1−xCdxTe with × ≥ 0.15 were obtained on (100) 3°, → (110) oriented CdTe substrates. Both n-type and p-type layers could be obtained. The mobility of these layers was measured over the temperature range of 10 K to 300 K. The mobility of n-type Hg.81Cd.19Te layers, measured at 2.1 kG, was 3.0 × 105cm2/V-sec at 60 K, falling to 2 × 105cm2/V-sec at 10 K. P-type layers were also grown, and are described in this paper.
LATTICE MATCHING IN HgCdTe-CdZnTe HETEROJUNCTIONS
Authors: Maekawa T. , Saito T. , Yoshikawa M. , Takigawa H. 
Published: March 2011

AbstractAn etch pit study has been made on misfit dislocations in (111) HgCdTe-CdZnTe heterojunctions grown by liquid phase epitaxy. It was shown that misfit dislocations were localized at the original surface of the substrate, because Zn diffused into the epilayer during epitaxial growth prevents movement of dislocations. For lattice matching between Hg0 7Cd0.3Te and Cd1−yZnyTe, the optimum ZnTe mole fraction of Cd1−yZnyTe was found to be 2.9%.
X-RAY MONITORING OF InGaAsP LAYERS GROWN BY VAPOR PHASE EPITAXY
Authors: MACRANDER A. T. , STREGE K. 
Published: March 2011

AbstractX-ray double crystal diffractometry provides a means of rapidly characterizing epitaxial structures. Because the technique is rapid and nondestructive and because it yields a wealth of information, rocking curves have been routinely obtained and extensively studied by us. We present here selective results illustrating the typical progression in layer quality which occurs from the initial growth in a reactor to the growth of device quality material.
X-RAY DIFFRACTION ANALYSIS OF EPITAXIAL STRUCTURES
Authors: PAINE BRUCE M. 
Published: March 2011

AbstractThe technique is described for use of x-ray double crystal diffractometry for analysis of epitaxial structures. This method has been shown to be very useful for characterizing a wide variety of configurations, ranging from single epitaxial layers to damaged superlattices. It yields depth profiles of structure factors and strains relative to the substrate, which can be directly related to layer thicknesses and compositions. Information about dislocations and random atomic displacements is also present. The key to this technique is computer fitting of the x-ray data with a model for the diffraction process, utilizing trial profiles for the strain and structure factors of the epitaxial layers. In the work to be presented a kinematic model for the diffraction is used. The technique is demonstrated with analyses of an Alx Ga(1−x) As single layer on GaAs, an AlSb/GaSb superlattice on GaSb, epitaxial CoSi2 on Si, and ion-implanted and annealed AlxGa(1−x)As superlattices on GaAs.
INITIAL STAGES OF EPITAXY OF METALS ON Si(lll)-7x7 STUDIED BY UHV ELECTRON MICROSCOPY
Authors: TAKAYANAGI K. 
Published: March 2011

AbstractInitial condensations of Cu, Ag and Au on Si(lll)-7x7 surface are seen continuously by video tape recording and intermittently by photographic films using an UHV electron microscope in reflection electron microscopy (REM). The growths of initial superlattice structures are found to relate with the steps of the 7x7 surface and the superlattice structures of a for Cu, for Ag and 5x2 for Au are nucleated at the upper side of the stepsand grow over the lower side terrace accompanied by the step movement. The growth of Au on Si(lll)-7x7 surface is seen in transmission electron microscopy (TEM) to supplement geometric information. It is found that the 5x2 domain of Au grows in the <llO>Si direction preferentially. The superlattice structures formed at submonolayer range are seen for the first time in TED pattern, which is useful to judge the previously proposed models from intensity distribution. REM-RHEED and TEM-TED allow us to study dynamic process of the initial growth stages of metals on Si(lll)-7x7 in real space and to analyse the geometrical structures of the superlattice structures at submonolayer.
The Structure and Composition of Interphase Boundaries in Ni/Ag-(001) Thin Films Doped with Au
Authors: Dregia S.A. , Bauer C.L. , Wynblatt P. 
Published: March 2011

AbstractComputer simulations of the Ni/Ag-(001) interphase boundary have been performed with the Embedded Atom Method. The relaxed atomic configurations, the periodic interaction potential, the shear modulus of the interface, and the interaction of an Au impurity with the interface have been evaluated. In addition, experimental studies have been conducted on the same system; and the structure and composition of the interface have been simultaneously examined.
NEW SUPERLATTICE ARCHITECTURE IN III-V COMPOUND SEMICONDUCTORS VIA CONTROL OF EPITAXY ON AN ATOMIC SCALE
Authors: PETROFF P. M. 
Published: March 2011

AbstractThe perfection and compositional stability of alternate monolayer compounds (AMC) structures deposited by molecular beam epitaxy as a function of several crystal growth parameters are reviewed. By using the (GaAs)1 - (AlAs)1 AMC structure as a prototype system, the effects of substrate temperature, and orientation on the AMC ordering are presented. Conditions for producing new superlattice architectures are discussed.
STRUCTURAL AND MAGNETIC PROPERTIES OF SINGLE CRYSTAL RARE EARTH Gd-Y SUPERLATTICES
Authors: Kwo J. , McWhan D. B. , Hong M. , Gyorgy E. M. , DiSalvo F. J. 
Published: March 2011

AbstractHigh quality single crystal rare earth Gd-Y superlattices with wavelength varying from 8to 42 atomic layers were grown by the recently developed metal molecular beam epitaxy technique. The crystallinity and coherence of the superlattices were examined by X-ray diffraction, and the profiles of composition modulation and strain modulation were determined from a quantitative analysis based on a simple diffusion model for the Gd-Y interfaces. The sharp boundaries achieved in these metallic superlattices are approaching those in semiconductor superlattices. The various in-plane magnetization behavior at low fieldsamong superlattices of different wavelengths suggests the possible presence of new magnetic ordering structures as caused by the artificial modulation.
CONDUCTION BAND ENERGY LEVELS IN SUPERLATTICES WITH COMPLEX UNIT CELLS
Authors: OSBOURN G. C. 
Published: March 2011

AbstractThe conduction band energy levels and wavefunctions in a number of superlattices with more than two layers per unit cell have been calculated using an effective mass model. Many of these structures exhibit energy levels which can be modeled as resulting from a conventional superlattice with a modified bulk conduction band minimum in the effective wells. These structures should be useful for extending the size of the superlattice periodsallowed in strained—layer superlattices.
QUANTUM CONFINEMENT EFFECTS IN ZnSe/ZnMnSe STRAINED-LAYER SUPERLATTICES
Authors: Bylsma R.B. , Frohne R. , Kossut J. , Becker W.M. , Kolodziejski LA. , Gunshor R.L. 
Published: March 2011

AbstractPhotoluminescence and photoluminescence excitation spectroscopy have been used to identify excited state energy levels in ZnSe/ZnMnSe strained-layer superlattices. Several ZnSe/ZnMnSe superlattices have been grown by MBE with different concentrationsof Mn in the barrier material and consequently with different degrees of lattice mismatch between the ZnSe well and ZnMnSe barrier materials. A strain-induced decrease of the band gap is observed in these structures. Photoluminescence excitation spectra reveal a strain dependent splitting of the heavy and light hole n=1 subbands. The magnitude of this splitting, as well as the observed photoluminescence red-shift, are compatible with expectations based on calculated strains and the deformation potentials of ZnSe.
MBE GROWTH OF NON-LATTICE MATCHED (BaCa)F2, (Pb,Sn)Se/(Ba,Ca)F 2 AND CdTe/(Ba,Ca)F2 ON Si SUBSTRATES
Authors: ZOGG H. , MAIER P. , NORTON P. 
Published: March 2011

AbstractGraded (Ca,Ba)F2 layers consisting of near lattice matched CaF2 at the Si interface and of BaF2 with 14% increased lattice constant at the top surface were grown by molecular beam epitaxy (MBE) on Si(111). Smooth and crackfree layers exhibiting Rutherford backscattering (RBS) channeling minima below 5% were obtained. Device quality epitaxial layers of PbTe, PbSe and (Pb,Sn)Se were grown on top of these structures. Mechanical stress at 300K was relaxed by athermal mechanisms in the fluoride- as well as in the Pb-salt films. - In preliminary runs, epitaxial CdTe-layers were obtained on Si(111) using the same fluoride-buffer film technique and which showed clear SEM electron channeling patterns.
Theoretical Methods for Calculating Electronic Properties of Semiconductor Superlattices
Authors: SCHULMAN JOEL N. 
Published: March 2011

AbstractA variety of theoretical models have been used to calculate the electronic properties of semiconductor superlattices. The methods vary in their ease of implementation, number of empirical parameters, and ability to incorporate physical effects. There is no “best” method; the choice of model is made on the basis of the desired property under investigation, such as subband energy levels, energy band dispersion and effective mass, strain effects, or optical spectra. The strength and limitations of the Kronig- Penney, envelope function, and tight-binding models will be reviewed, including one-, two-, and multi-band versions. The relationship of superlattice to bulk band structure, and the issue of dispersion in the growth and in-plane directions will be illustrated with the examples of the CaAs-GaAlAs and HgTe-CdTe superlattices.
PHOTOCONDUCTIVITY, PHOTOREFLECTANCE AND PHOTOLUMINESCENCE OF GaAs-AlAs MULTIPLE QUANTUM WELLS
Authors: NEFF H. , BACHMANN K. J. , LAIDIG W. D. 
Published: March 2011

AbstractEmploying temperature dependent photoconductivity, photoluminescence and photoreflectivity measurements, we have analyzed a GaAs-AlAs multiple quantum well. The above optical techniques clearly resolve the fundamental inter-subband transitions, including heavy hole-light hole splittings. At T < 60K an anomalously high photoconductivity was discovered below the direct inter-subband transitions and is attributed tentatively to the presence of extrinsic interface states within the bandgap. For T > l00K the fundamental indirect transition was discovered and associated with LO (L) - phonon absorption.
DIRECT OBSERVATION OF INTERFACE TRAPS IN OMVPE-GROWN SELECTIVELY AlGaAs/GaAs HETEROSTRUCTURE USING MODIFIED DLTS
Authors: TAKIKAWA M. , OOHORI T. , KASAI K. , KOMENO J. , SHIBATOMI A. 
Published: March 2011

AbstractBy using a DLTS technique, we measured the drain current transient from a gate bias pulse for a HEMT. Two negative peaks and one positive peak were observed. From the analysis of the spectra, we found that the positive peak was due to the interface trap. The density of the interface trap was determined from a DLTS fitting procedure. The effect of the interface traps on the electrical properties of the heterostructure are discussed.
INTERFACIAL DEFECTS AND EPITAXY
Authors: POND R.C. 
Published: March 2011

AbstractIt is shown that interfacial defects are characterised by combinations of symmetry operations, one from each of the adjacent crystals. This approach demonstrates that the variety of possible interfacial defects is broader than had been previously recognised, and includes disclinations and dispirations in addition to dislocations. The condition of the initial substrate surface is shown to have a very important influence on the character and stability of interfacial defects.
DEPTH-DEPENDENT MIXING OF AN AlAs-GaAs SUPERLATTICE BY ION IMPLANTATION
Authors: SCHWARZ S.A. , VENKATESAN T. , BHAT R. , KOZA M. , YOON H.W. , ARAKAWA Y. , MEI P. 
Published: March 2011

AbstractThe effects of implantation and annealing on an AlAs-GaAs superlattice grown by OMCVD is examined with SIMS (secondary ion mass spectrometry). Several 180 keV 28Si+ implants, with doses ranging from 3 × 1013 to 3 × 1015 cm−2, are examined before and after a three hour 850 C anneal. While the implantation by itself causes some intermixing in the vicinity of the projected range, the 850 C thermal anneal induces significant mixing at depths well beyond the implant range. In the region of maximum implant damage, however, the post-thermal mixing effect is inhibited. Depth dependent diffusion lengths of Al and Si are derived from the SIMS data. The diffusion coefficient of Si is markedly enhanced in the mixed regions.
INTERMIXING OF ION-IMLANTED AlGaAs/GaAs SUPERLATTICES
Authors: Ralston J. , Wicks G.W. , Eastman L.F. , Rathbun L. , DeCooman B.C. , Carter C.B. 
Published: March 2011

AbstractCross-sectional Transmission Electron Microscopy, Sputter-Auger spectroscopy, and Raman spectroscopy have been used to study intermixing and residual damage in annealed ion-implanted Al0.3Ga0.7As/GaAs superlattices. Several implant species were studied Nse, Si, Mg, Be). Three different regions can be distinguished in the annealed ionimplanted superlattice samples. The topmost region contains a dense network of stacking faults and microtwins, residual damage from an implantation-amorphized region which has recrystallized during annealing. In the second region, which is relatively defect-free, either total, or at least appreciable intermixing of the GaAs and Al0.3Ga0.7As layers occurs. For fixed annealing conditions, the degree of intermixing varies with the mass of the implanted species. The third region contains many small dislocation loops which form by the agglomeration of point defects during implantation or the subsequent annealing process. Raman spectroscopy is used to compare the degree of intermixing and residual damage between AlGaAs alloys generated by superlattice disordering and uniform “as-grown” alloys of the same composition which have undergone identical implant and anneal treatments.
MULTILAYER X-RAY MIRRORS, A FIRST STEP TOWARDS THE CUSTOM DESIGN OF NEW MATERIAL PROPERTIES
Authors: SPILLER EBERHARD 
Published: March 2011

AbstractSoft x-ray reflectivities up to a factor 104larger than those of the best homogeneous materials have been obtained with multilayers coatings. Thickness control and boundary definition has been achieved on an atomic scale with amorphous films. We will review design, fabrication, performance and characterization of the coatings and discuss possibilities to extent these methods to the improvement of other material properties.
MULTILAYER X-RAY REFLECTORS: EFFECTS OF LAYER IMPERFECTIONS
Authors: Wood J. , Grupido N. , Hart K. , Flessa S. , Kadin A. , Keem J. , Ferris D. 
Published: March 2011

AbstractPeriodic multilayer structures, consisting of largely amorphous alternating layers of heavy and light elements, have been fabricated by sputtering techniques. Investigations have been carried out into the effects of various types of layer imperfections on the x-ray optical properties of these multilayers. These have included extensive numerical modeling of real multilayers (using a computational scheme based on the complete dynamical theory) with simulations of diffused interfaces and deviations from constant d-spacing. Results are presented for examples of W–C and Hf–Si multilayers, with comparison of measurements at Cu–K to the theoretical model.
THERMAL, STABILITY OF W/C MULTILAYER FILMS
Authors: Takagi Yasuo , Pawlik David A. , Kadin Alan M. , Flessa Steven A. , Hart Keith L. , Keem John E. , Tyler John E. 
Published: March 2011

Arstract:W(15 Å)/C(15 Å), W(50 Å)/C(50 Å) and W(100 Å)/C(100 Å) periodic multilaver films were prepared by magnetron sputtering and suhsequently annealed at 980, 730 and 500°C. The changes of layered and crystal structures were studied by x-ray diffraction. The results depended largely on the thickness of W layers and their initial crystal struictures of W. The kinds of transformations are classified into two types: one is the non-reacting type in the case of multilayers having the thinner W layers like W(15 Å)/C(15 Å), in which the crystallization of W layers prevails over the reactions between W and C layers; the other, the reacting type in the multilayers having thicker W layers like W(50 Å)/C(50 Å) and W(100 Å)/C(100 Å), in which reactions Prevail over crystallization. A tentative model in which the effective reaction rate between amorphous–W and amornhous–C is much smaller than that of crystalline-W(beta phase) and amorphous-C is proposed to explain the origin of the phenomena.
SUPERCONDUCTING PROPERTIES OF TERNARY GRAPHITE INTERCALATION COMPOUNDS
Authors: Chaiken A. , Roth G. , Enoki T. , Yeh N. C. , Dresselhaus M. S. , Tedrow P. 
Published: March 2011

AbstractGraphite intercalation compounds (GIC's) are metal-semimetal superlattices which exhibit crystalline order, and have atomically perfect interfaces between the layers of the constituent species. From the standpoint of superconductivity, the KHg-GIC's are particularly interesting. The preparation and properties of these compounds are described, along with a series of recent experiments with hydrogen doping which have helped to elucidate their electronic properties. A density of states model suggested by the results of the hydrogen–doping experiments is presented and used to explain the variation of the superconducting transition temperature in these materials.