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Families of very high-index planes, such as those which bifurcate spontaneously to form a hill-and-valley structure composed of opposing facets, provide natural templates for the directed growth of position-controlled self-organized nanostructures with shapes determined by the facet width ratio R. For example, deposition of a few ML of Ge on Si(173 100 373), corresponding to R(113/517) = 1.7, results in a field of 40-nm-wide Ge nanowires along [72 187] with a uniform period of 60 nm.

Compressively strained Si[sub 0.7]Ge[sub 0.3] layers were grown on Si(001) by gas-source molecular beam epitaxy from Ge[sub 2]H[sub 6]/Si[sub 2]H[sub 6] mixtures at 450°C. The combination of the relatively low growth temperature and high steady-state hydrogen surface coverage, θ[sub H]=0.52 monolayer, completely suppresses strain-induced roughening and provides extremely flat surfaces with root mean square widths w < 1.5 Å for fully coherent layers. These samples were used as the starting point to probe mechanisms that control misfit-dislocation-induced surface roughening (i.e., crosshatch) along 90°-rotated 〈110〉 directions. For film thicknesses t just larger than the critical value for misfit dislocation formation, t[sub c] ... 1000 Å, surface roughness is dominated by single- and multiple-atomic-height steps generated by the motion of threading dislocations associated with interfacial misfits. The surface steps are preferential H desorption sites and the increase in total step length results in a decrease in θ[sub H] on terraces as well as at step edges. The latter effect allows a higher adatom crossing probability at ascending steps, leading to the formation of periodic ridges in response to local strain fields associated with misfit dislocation clusters; w increases from 3.1 Å at t = 1350 Å (corresponding to strain relaxation R of 1%) to 27 Å at t = 4400 Å (R = 78%). Simultaneously, the decrease in θ[sub H] on terraces strongly affects film growth kinetics as the deposition rates increase from 10 Å min[sup -1] with t

Presents a study which investigated the mechanisms for the low-temperature growth of crytalline germanium and silicon films from germanium hydroxide and silicon hydrogen[sub4]. Model for the epitaxial growth of germanium from germanium hydrogen[sub4]; Discussion of the hydroxide desorption process; Conclusions.

Presents information on a study which discussed the redistribution of dopants during the solid-phase reaction of chromium (Cr) with silicon (Si) substrates to form CrSi[sub2]. Silicide growth and profile calibrations; Discussion on dopant redistribution; Application of Rutherford backscattering spectrometry on dopants investigated.

Presents a study that investigated the evolution of surface roughness in epitaxial Si[sub0.7]Ge[sub0.3] alloys grown on silicon(001) as a function of temperature, thickness and substrate miscut. Atomic microscopy of the surface roughness; Effect of substrate vicinality on strain-induced roughening; Background on surface morphology and roughness evolution during thin-film deposition.

Deals with a study which investigated crystal growth, doping and electronic properties of epitaxial silicon(001) grown at 80-750 °C by ion-beam sputter deposition. Experimental procedures; Results and discussion; Conclusions.

Deals with a study which investigated growth microstructure and strain relaxation in low-temperature epitaxial Si[sub1-x]Ge[subx] alloys deposited on silicon(001) from hyperthermal beams. Experimental procedure; Experimental results; Conclusion.

Presents a study that examined the growth of epitaxial aluminum nitride(0001) on silicon(111) by reactive magnetron sputter deposition. Experimental procedure; Results and discussion; Conclusions.

Focuses on a study which presented temperature-dependent photoluminescence (PL) measurements of silicon films during molecular beam epitaxy. Experimental procedure; Carrier concentrations and depth profiles; PL dependency on ion energy and film growth temperature.

Deals with a study which grew boron-doped silicon films on silicon substrates by gas-source molecular beam epitaxy (GS-MBE) using Si[sub2]H[sub6] and B[sub2]H[sub6]. Background on GS-MBE; Experimental procedure; Experimental results; Discussion.

Deals with a study which determined the growth rate of epitaxial silicon films on silicon as a function of temperature and silicon hexahydride impingement flux. Advantages of gas-source molecular-beam epitaxy (GS-MBE) over solidable source MBE; Characteristics of the deposition rate data used in the study; Description of the growth kinetics of GS-MBE Si from silicon hexahydride.

Presents a study that discussed the use of a single-grid ultra-high-vacuum-compatible ion source to provide accelerated indium+ -dopant beams during silicon (100) growth by molecular-beam epitaxy. Factors incorporated with indium; Description of temperature-dependent (77-400 K) mobilities; Technique used for the growth of epitaxial silicon films.

Presents a study that used a single-grid broad-beam ion source for low-energy accelerated indium (In)[sub+] ion beam doping during growth of silicon layers by molecular-beam epitaxy. Indium incorporation behavior; Use of secondary ion mass spectroscopy; Determination of the abrupt doping profiles.

Presents a study which determined the incorporation probability σ[sub silicon] and the segregation-induced profile broadening Δ[sub s] of silicon in molecular-beam epitaxy. Depth profiles of absolute silicon concentrations; Analysis on secondary ion mass spectrometry; Results of experimental procedure.

Reports on laser-assisted chemical vapor deposition of silicon. Growth temperature of epitaxial and polycrystalline layers of silicon; System used for the laser-assisted chemical vapor deposition of silicon; Cause of the increase in gain size and preferred orientation as well as the increase in the conductivity of films grown on silicon dioxide.

Hf1-x-yAlxSiyN(0 ≤ × ≤ 0.14, 0 y 0.12) single layer and multilayer films are grown on Si(001) at 250?°C using ultrahigh vacuum magnetically unbalanced reactive magnetron sputtering from a single Hf0.6Al0.2Si0.2 target in mixed 5%-N2/Ar atmospheres at a total pressure of 20 mTorr (2.67?Pa). The composition and nanostructure of Hf1-x-yAlxSiyN films are controlled by varying the energy E i of the ions incident at the film growth surface while maintaining the ion-to-metal flux ratio constant at eight. Switching E i between 10 and 40 eV allows the growth of Hf0.78Al0.10Si0.12N/Hf0.78Al0.14Si0.08N multilayers with similar layer compositions, but in which the Si bonding state changes from predominantly Si-Si/Si-Hf for films grown with Ei = 10eV, to primarily Si-N with Ei = 40eV. Multilayer hardness values, which vary inversely with bilayer period Λ, range from 20 GPa with Λ = 20 nm to 27 GPa with Λ = 2 nm, while fracture toughness increases directly with Λ. Multilayers with Λ = 10 nm combine relatively high hardness, H ~ 24 GPa, with good fracture toughness. [ABSTRACT FROM AUTHOR]

The morphological and thermal stability of conducting NiSi films formed on Si(001) are significantly enhanced by pre-implantation of the Si wafer with BF[sup +, sub 2]. In the absence of F, the maximum silicidation temperature T[sub max] is 650 °C; higher temperatures lead to the formation of the competing high-resistivity NiSi[sub 2] phase. T[sub max], however, is increased to ≥750 °C during NiSi formation on Si(001) implanted with 20 keV BF[sup +, sub 2] at a dose of 5 × 10[sup 15] cm[sup -2]. The observed enhancement in NiSi thermal stability is due to F segregation to the silicide/Si(001) interface and silicide grain boundaries, which retards NiSi grain growth, leading to much smoother layers, and inhibits NiSi[sub 2] nucleation. [ABSTRACT FROM AUTHOR]

Temperature-dependent photoluminescence (PL) measurements have been used to characterize 5-μm-thick Si(100) epitaxial layers doped in situ during molecular beam epitaxial growth with low-energy (100, 500, and 1000 eV) 11 B+ ions at growth temperatures of 500, 650, and 800 °C. Moderate doping (NB ∼1017 cm-3) yielded PL features comprised of both sharp and broad peaks in the boron bound exciton (B-BE) region. At 4.2 K a broad B-BE feature near 1086 meV dominated, although the sharp transverse optical phonon-assisted B-BE peak (B1TO ) at 1092.5 meV was resolvable for NB<1017 cm-3. Increasing the PL sample temperature above 4.2 K caused a rapid decay of the broad B-BE peak intensity, thus permitting comparison of B1TO intensity for a range of ion energies and growth temperatures. At 10 K, a bulk-like spectrum containing a sharp B1TO peak with weaker multiexciton peaks B2TO and B3TO was observed for the film growth at the highest temperature and lowest ion energy (800 °C and 100 eV). However, the intensity of the B1TO peak decreased with decreasing growth temperature (constant ion energy) and with increasing ion energy (constant growth temperature). Samples grown at the lowest temperature (500 °C) displayed very different PL spectra with much weaker line emission, a rising PL background, and additional lines near 1040 meV due to ion-induced residual lattice defects. Quenching of B1TO and the other sharp B-BE peaks was accompanied by an increase in the N1 peak at 745.7 meV. [ABSTRACT FROM AUTHOR]

Low-temperature (4.2K) photoluminescence (PL) has been used to characterize Si(100) films doped with EAs =200, 500, and 1000 eV 75 As+ ions during growth by molecular beam epitaxy on n+ Sb-doped substrates at temperatures Ts between 500 and 800 °C. Sharp no-phonon, transverse-optical, and transverse-acoustic phonon-assisted bound-exciton (BE) Peaks associated with As dopant species, together with broader, weaker, Sb-related BE peaks, were the dominant PL features obtained from 5-μm-thick layers. No peaks ascribable to residual ion-induced damage were observed in films grown at 650 °C with EAs =200 eV or Ts =800 °C with EAs =200, 500, and 1000 eV. However, reducing the film growth temperature to 500 °C with Eas =200 eV gave rise to a strong ion-damage PL peak at 1039.7 meV. Furthermore, both undoped and As ion-doped films grown at 500 °C exhibited a gradual increase in the PL background below 890 meV which we believe was due to quenched-in point defects. Complementary deep level transient spectroscopy measurements showed electron trap states (concentrations[bar_over_tilde:_approx._equal_to]1014 cm-3) at energies of 0.06 an d-0.52 eV below the conduction-band edge for films grown at 500 °C with EAs =200 eV. No traps were observed in the ion-doped Ts=650 and 800 °C samples. [ABSTRACT FROM AUTHOR]

A low-energy ultrahigh-vacuum compatible ion gun with single-grid optics was used to provide accelerated Sb ion doping during the growth of Si(100) by molecular beam epitaxy (MBE). The incorporation probability of accelerated Sb in MBE Si films grown at 800 °C with an ion acceleration potential of 150 eV was near unity, more than four orders of magnitude higher than for thermal Sb. The films exhibited complete dopant substitutionality and temperature-dependent electron mobilities were equal to the best reported bulk Si values for Sb concentrations up to 2×1019 cm-3, more than an order of magnitude higher than obtainable by thermal Sb doping during Si MBE. Transmission electron microscopy examination of all films showed no evidence of dislocations or other extended defects. [ABSTRACT FROM AUTHOR]

The growth rates R[sub Si] of Si layers deposited on Si(011)"16x2" by gas-source molecular beam epitaxy from Si[sub 2]H[sub 6] were determined as a function of temperature T[sub s] (400-975 °C) and Si[sub 2]H[sub 6] flux J[sub Si[sub 2]H[sub 6]](5.0x10[sup 15]-9.0x10[sup 16] cm[sup -2] s[sup -1]). R[sub Si] ranges from 0.0015 μm h-1 at T[sub s]=400 °C to 0.415 μm h-1 at T[sub s]=975 °C with J[sub Si[sub 2]H[sub 6]]=2.2x10[sup 16] cm[sup -2] s[sup -1]. In the surface-reaction-limited regime at T[sub s]<725 °C, R[sub Si] initially exhibits an exponential decrease with 1/T[sub s], then decreases at a slower rate at T[sub s]≤550 °C as an additional deposition pathway becomes operative. In the impingement-flux-limited regime, 725≤T[sub s]≤900 °C, R[sub Si] is independent of T[sub s] but increases linearly with J[sub Si[sub 2]H[sub 6]]. At T[sub s]>900 °C, R[sub Si](T[sub s]) increases with T[sub s] due to surface roughening. Overall, R[sub Si](J[sub Si[sub 2]H[sub 6]],T[sub s]) is well described at T[sub s]≤900 °C by a kinetic model incorporating two competing film growth mechanisms: (1) dissociative chemisorption of Si[sub 2]H[sub 6] onto dangling bonds followed by fast surface dissociation steps and second-order H[sub 2] desorption from the surface monohydride phase; and (2) Si[sub 2]H[sub 6] insertion into Si-H surface bonds followed by second-order desorption of SiH[sub 4]. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]