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Studies the characterization of gallium arsenide layers grown directly on silicon substrates by metalorganic chemical vapor deposition. Advantages of the heteroepitaxial growth of gallium arsenide on silicon substrates; Details on the experiment; Discussion on the results of the study.

Presents a study that examinee the pulsed laser and furnace annealing of nitrogen-implanted silicon. Comparison of the liquid and solid phase regrowth; Analysis of the diffusion of nitrogen; Investigation of the formation of nitride.

Discusses calorimetric studies of crystallization and relaxation of amorphous silicon and germanium prepared by ion implantation. Determination of the amorphous-crystal interface velocity; Interface velocity for crystallization on substrates; Advantages of ion implantation in the study of thermodynamics and kinetics of crystallization.

Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, transmission electron microscopy measurements of implantation damage were combined with B diffusion experiments using doping marker structures grown by molecular-beam epitaxy (MBE). Damage from nonamorphizing Si implants at doses ranging from 5 × 10[sup 12] to 1 &times 10[sup 14]/cm² evolves into a distribution of {311} interstitial agglomerates during the initial annealing stages at 670815 °C. The excess interstitial concentration contained in these defects roughly equals the implanted ion dose, an observation that is corroborated by atomistic Monte Carlo simulations of implantation and annealing processes. The injection of interstitials from the damage region involves the dissolution of {311} defects during Ostwald ripening with an activation energy of 3.8±0.2 eV. The excess interstitials drive substitutional B into electrically inactive, metastable clusters of presumably two or three B atoms at concentrations below the solid solubility, thus explaining the generally observed immobile B peak during TED of ion-implanted B. Injected interstitials undergo retarded diffusion in the MBE-grown Si with an effective migration energy of ∼3.5 eV, which arises from trapping at substitutional C. The concept of trap-limited diffusion provides a stepping stone for understanding the enormous disparity among published values for the interstitial diffusivity in Si. The population of excess interstitials is strongly reduced by incorporating substitutional C in Si to levels of ∼10[sup 19]/cm³ prior to ion implantation. This provides a promising method for suppressing TED, thus enabling shallow junction formation in future Si devices through dopant implantation. The present insights have been implemented into a process simulator, allowing fo... [ABSTRACT FROM AUTHOR]

Provides information on a study which investigated the gettering mechanisms of iron in silicon. Details of gettering layers into iron-contaminated silicon wafers by means of high-energy ion implantation; Methodology of the study; Results and discussion.

Presents a study that investigated extended defects induced in silicon by high energy implantation. Analysis of defects by plan-view and cross-sectional transmission electron microscopy studies and defect etching measurements; Effects of preexisting impurities, implantation dose and annealing conditions on the formation and density of the dislocations; Background on high energy ion implantation into silicon.

Deals with a study which investigated the effects of low-dose ion implants with silicon, neon and fluorine on the transient enhanced diffusion of boron in silicon after annealing at high temperature. Background to the study; Experimental procedures; Results and discussion.

Presents information on a study which defined the processing parameters which will optimize the photoluminescence intensity of erbium implanted in silicon. Methods; Results; Discussion.

Presents information on a study which examined the electrical and defect properties of ion-implanted erbium in silicon. Methods; Results; Discussion.

Presents a study that investigated the effect of ion implantation and solute atoms on the interdiffusion in amorphous silicon/germanium multilayers. Diffusivities of other solutes such as platinum and bismuth; Investigation of the samples before and after ion implantation or thermal annealing; Effect of boron implantation.

Examines the dependence on temperature, dose and dose rate of the intermixing of silicon (Si) and germanium (Ge) atoms in the amorphous phase. Use of the Rutherford backscattering spectrometry technique; Relaxation in the diffusion coefficient; Target atom displacement in Si-Ge alloys of different average compositions.

Pulsed laser irradiation of amorphous Si has been used to produce undercooled liquid Si from which the amorphous phase can directly form. Implanted In, Bi, and As impurities are observed to diffuse and be segregated in a novel fashion by liquid-amorphous interfaces moving from the bulk and surface. Ultrathin impurity segregation layers can be formed within amorphous Si by this process. The first measurements of interracial segregation coefficients during a liquidamorphous transition are found to be similar to liquid-crystal values at the same velocity. [ABSTRACT FROM AUTHOR]

Ion implantation of Si (60 keV, 1×1014/cm2) has been used to introduce excess interstitials into silicon predoped with high background concentrations of B, which were varied between 1×1018 and 1×1019/cm3. Following post-implantation annealing at 740 °C for 15 min to allow agglomeration of the available interstitials into elongated {311} defects, the density of the agglomerated interstitials was determined by plan-view transmission electron microscopy observation of the defects. We report a significant reduction in the fraction of excess interstitials trapped in {311} defects as a function of boron concentration, up to nearly complete disappearance of the {311} defects at boron concentrations of 1×1019/cm3. The reduction of the excess interstitial concentration is interpreted in terms of boron-interstitial clustering, and implications for transient-enhanced diffusion of B at high concentrations are discussed. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The removal of lattice damage and consequent activation by rapid thermal annealing of implanted Si, Se, Zn, and Be in GaAs was investigated by capacitance-voltage profiling, Hall measurements, transmission electron microscopy (TEM), secondary ion mass spectrometry, and Rutherford backscattering. The lighter species show optimum electrical characteristics at lower annealing temperatures (∼850 °C for Be, ∼950 °C for Si) than the heavier species (∼900 °C for Zn, ∼1000 °C for Se), consistent with the amount of lattice damage remaining after annealing. TEM reveals the formation of high densities (107 cm-2) of dislocation loops after 800 °C, 3 s anneals of high dose (1×1015 cm-2) implanted GaAs, which are gradually reduced in density after higher temperature anneals (∼1000 °C). The remaining loops do not appear to affect the electrical activation or carrier mobility in the implanted layer, the latter being comparable to bulk values. [ABSTRACT FROM AUTHOR]

The diffusion and precipitation of several ion implanted impurities in amorphous Si have been observed at temperatures of 300–600 °C. Typical slow diffusers in crystalline Si, such as As, In, Sb, and Bi, show little or no diffusion at low concentrations. At high concentrations (>1 at. %), they diffuse rapidly with D>=10-15 cm2/s in the temperature range 500–600 °C. Typical fast diffusers in crystalline Si, such as Cu and Au, diffuse in amorphous Si with D>10-12 cm2/s at 400–600 °C. Precipitation has been observed for both the fast and slow diffusers in amorphous Si. [ABSTRACT FROM AUTHOR]

The kinetics of solid phase epitaxy (SPE) have been measured in MeV ion-implanted amorphous Si layers up to 5 μm thick. Epitaxial crystallization in these layers occurs at a constant rate throughout the entire film, without loss of interface planarity or competition from random nucleation or twin formation. The activation energy for SPE in thick layers is found to be 2.70 eV, in excellent agreement with the value determined previously in much thinner films. The SPE kinetics are shown not to depend on the implant dose for doses up to 1000 times the threshold for amorphization. The presence of water vapor in the annealing ambient during SPE results in the indiffusion of hydrogen and a concomitant reduction of the SPE growth rate at distances as great as 2 μm from the surface. This effect may have important implications for the development of a microscopic model of the SPE process in silicon. [ABSTRACT FROM AUTHOR]

Amorphous Si layers prepared by MeV Si implantation of (100) wafers have been studied by scanning and isothermal calorimetry. A homogeneous heat release of 5.1±1.2 kJ/mole and an interfacial heat release, due to crystallization, of 13.4±0.7 kJ/mole have been measured. Isothermal measurements unambiguously demonstrate the occurrence of the homogeneous release. The heat released isothermally at each temperature is between 6% and 8.5% of the total homogeneous release, and the time constants are only very weakly temperature dependent. [ABSTRACT FROM AUTHOR]

The radiation-enhanced diffusion of implanted Au markers in amorphous Si has been measured in the temperature range 77–693 K. Samples were irradiated with 2.5 MeV Ar ions. The diffusion coefficients show three well-defined regions. For temperatures <400 K, diffusion is athermal and due to ballistic mixing. For temperatures in the range 400–700 K diffusion is Arrhenius-type with an activation energy of 0.37 eV and is considerably enhanced over the normal thermal diffusion. The defects that cause the enhanced diffusion come from nuclear energy loss processes. Thermal diffusion, with an activation energy of 1.42 eV, dominates at temperatures greater than 750 K. [ABSTRACT FROM AUTHOR]

Ion-beam-induced epitaxial recrystallization of Au-implanted amorphous silicon at temperatures >400 °C has been studied. Crystallization was induced using a 2.5 MeV Ar beam. Segregation of Au at the moving crystal/amorphous silicon interface occurs with an interface velocity of 5 Å/s. At high Au concentrations, the interface breaks down with the formation of twins. The twinned crystal/amorphous interface then propagates under further irradiation with a reduced interface velocity of 3 Å/s. Unusual Au redistribution profiles are obtained as a result of the sudden change in interface morphology. The Au profiles are interpreted on the basis of classical segregation theory with the interfacial segregation coefficient changing from 0.0012 to 0.02 at the onset of twin formation. [ABSTRACT FROM AUTHOR]

Detection and gettering of Co contamination in processed Si is an important issue in integrated circuit fabrication. In this work, Co was intentionally introduced into Si by ion implantation, and its diffusion monitored by secondary ion mass spectroscopy. The surface layer recombination lifetime in p/p[sup +] epitaxial Si is unaffected by the Co at doses of 1x10[sup 11] cm[sup -2] or 1x10[sup 12] cm[sup -2]. In the case of 2.5 MeV, 4x10[sup 14] B/cm[sup 2] ion implanted bulk Si, two mechanisms for Co redistribution during high temperature furnace, 900 °C, 30 min, processing are evident. First, regions of high boron concentration provide gettering sites for Co contamination. Second, the final distribution of Co in Si reflects ion-implantation induced defect evolution during annealing. Both mechanisms will operate during device processing and will control the effect of the metal on the electrical properties of the Si. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A technique for profiling the clustered-vacancy region produced by high-energy ion implantation into silicon is described and tested. This technique takes advantage of the fact that metal impurities, such as Au, are trapped in the region of excess vacancies produced by MeV Si implants into silicon. In this work, the clustered-vacancy regions produced by 1-, 2-, and 8-MeV Si implants into silicon have been labeled with Au diffused in from the front surface at 750 °C. The trapped Au was profiled with Rutherford backscattering spectrometry. The dynamics of the clustered-vacancy region were monitored for isochronal annealing at 750–1000 °C, and for isothermal annealing at 950 °C, for 10–600 s. Cross-sectional transmission electron microscopy analysis revealed that after the drive-in anneal, the Au in the region of vacancy clusters is in the form of precipitates. The results demonstrate that the Au-labeling technique offers a convenient and potentially quantitative tool for depth profiling vacancies in clusters. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Carbon diffusion in silicon has been investigated by using a superlattice structure of carbon spikes (10 nm-wide, carbon concentration >10[sup 19] cm[sup -3], spikes spaced 100 nm apart) grown epitaxially by Si molecular beam epitaxy. Samples were annealed in the range between 680 and 850 °C. The diffusive behavior of carbon was monitored by secondary ion mass spectrometry. Carbon diffusion profiles observed at temperatures above 800 °C show highly nonregular behavior. The diffusion results are interpreted in terms of the kick-out mechanism. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The capture of a flux of vacancies in Si by a band of extrinsic dislocation loops has been observed in Sb doping superlattices. Annealing Sb doping superlattices containing a band of dislocation loops in NH[sub 3] results in an injection of vacancies, which enhances the diffusion of Sb spikes located between the surface and loop band. By extracting the diffusivity in the Sb spikes on either side of the loop band, we conclude that over 90% of the injected vacancies are captured by the loops. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]