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The velocity of surface acoustic waves (SAW) as a function of composition of Ga[As.sub.1-x][N.sub.x]/GaAs(100) epilayers grown by organometallic vapor phase epitaxy was determined by using high-resolution Brillouin spectroscopy experiments. The approximation of a linear compositional dependence of the Ga[As.sub.1-x][N.sub.x] elastic constants could be used for stress evaluation in Ga[As.sub.1-x][N.sub.x] epilayers.

A study presents a concept for the implementation of a compliant substrate by using a buried layer of nanocavities. The findings of the results show that strain relaxation are enhanced for hetrostructures grown on substrates with nanocavities.

A new study investigates C incorporation and lattice sites on Ge1-yCy alloy layers (y< or = 0.02) grown on Ge(001) at temperatures between 200 and 550 deg C.

The optical properties and hetero junction band alignment are presented for fully coherent strain-compensated InAsxP1-x/GayIn1-yP multilayer structures grown on InP(001).

The effect of misorientation (001) InP substrates on the optical characteristics of InAs in InP was studied.

The Stokes shift in InAsP/InP and InGaP/InP multiple quantum wells was analyzed.

Research was conducted to examine an improved method of analyzing simultaneously the current-voltage and capacitance-voltage properties of metal-insulator-semiconductor diodes. The effect of Zn doping concentration on the current transport in Au MIS contacts fabricated on In0.21Ga0.79As layers was studied using the method. Results indicate that the form of the expression giving R does not allow the derivation of a simple analytical expression for the voltage dependence of I(sub RG).

The photoluminescence (PL) and optical absorption spectra of a series of InGaP/InP tensile strained layer multiple quantum wells are studied. Results show that at low temperature, the recombination energy of band-tail localized excitons is smaller than the free exciton energy leading to a substantial energy difference between absorption and PL peaks. It is also shown that the Stokes shift is in better agreement with the optical absorption width which indicates samples with high crystalline quality.

A study was conducted to characterize time-resolved differential reflections in InAs(sub x)P(sub 1-x)/InP strained-multiple-quantum wells. The evolution of the differential reflection dynamics was analyzed based on changes in the refractive index and cap absorption. Results indicated that carrier diffusion in the cap layer and barriers support a critical role in differential reflection dynamics.

Optical absorption and photoluminescence studies were conducted on low pressure metal-organic vapor phase epitaxy-grown strained-layer InAsxP1-x/InP(001)(x

A theoretical analysis on the effects of band alignment and barrier height variations on device physics is presented, along with two important design principles for band structure engineering of the multi-quantum well stack. The application of these design principles on high speed, low drive voltage optical modulators may enhance overall performance of Stark effect devices when used in combination with balanced band alignments and low valence band carriers.

A study was conducted on the temperature dependence of tunnel metal-insulator-semiconductor structure capacitance-voltage and current-voltage properties using a new self-consistent approach. Experimental validation of the proposed method was carried out through comparisons with interface state density distribution values for thermal equilibrium. The proposed approach yielded estimates for insulating layer transmission coefficient, effective barrier height and insulator layer thickness.

Heteroepitaxial InP layers were grown on Si(111) by metalorganic vapor phase epitaxy utilizing thermal cycle growth. The best crystallographic and optical quality was produced when thermal cycle growth was started after only a thin InP layer had been deposited. Thermal cycling was found to cause a net decrease in defect density in the interfacial region. Thermal strain induced energy splitting of 3.8 meV between the free exciton emissions associated with heavy and light holes.

Experimental studies help determine the photoluminescence spectra of InAsP/InP strained quantum wells as a function of temperature between 7 and 300 K. Theoretical predictions of photoluminescence, taking into account the temperature-stimulated changes in band gap, carrier effective mass, exciton binding energy and biaxial strain, agree well with the experimental results. Evolution of the strained band gap in the well is the major reason for the temperature dependence of quantized transition energies in strained quantum wells. Band gap of the bulk material in the well influences the dependence of quantized transitions on temperatures in lattice-matched quantum wells.

Evaporation of Au over a Zn doped epitaxial layer of InP, grown by low pressure metalorganic vapor phase epitaxy, yields Au/P-InP Schottky diodes with a metal-thin interface layer semiconductor (MIS) on a highly doped InP substrate. Interface layer thermionic emission theory explains the voltage dependence of reverse current in the temperature range between 300 K and 393 K. Zero bias barrier height values, obtained from an analysis of voltage-current characteristics, agree with those obtained from capacitance-voltage data at temperatures between 300 K and 393 K.

GaInP epilayer optoelectronic and structural properties such as isotropic and anisotropic strain relaxation on sulfur-doped InP substrates are important for interpreting confined state carrier optical spectra in strained-layer superlattices and multiple quantum wells. Photoluminescence and optical absorption facilitated the transition between the light and heavy hole valence bands and conduction band.

High-resolution photoluminescence spectroscopy and X-ray diffractometry analyze strain effects in binary high-purity InP epilayers grown on slightly mismatched substrates. The epilayer-based dissociations of donor-bound exciton excited states agree with experimental values. The InP bound exciton transition's strain-induced splitting rate is relatively small with respect to free exciton states.

An analysis of the atomic-layer epitaxy (ALE)-induced growth and structural characteristics of InP, InAs/InP-strained quantum wells and InAs/InP-strained layer lattices reveal that ALE is a good method for growth of highly strained heterostructures containing atomically controlled interfaces. X-ray diffraction, reflectometry and Raman spectroscopy analyze the folded and unfolded acoustic modes of the structures.

Vaporization of Au on chemically etched surfaces of Zn doped InGaAs crystalline layers which were developed on greatly p-doped GaAs layers by metalorganic vapor phase epitaxy synthesizes Au/p-InGaAs Schottky barrier diodes. It is possible to get superior quality Au Schottky contacts to chemically etched surfaces of InGaAs layers. As the doping concentration varies, a 10% variation in the barrier height for Au/p-InGaAs Schottky diodes is detected.

Photoluminescence (PL) and photoconductivity (PC) measurements are used in the study of the defect energy levels in metalorganic vapor deposition (MOCVO) grown GaxIn(1-x)P/InP:S epilayers. The study shows that the epilayer composition and the dominant deep-level peaks of the samples grown on the same substrate are related to each other and the dominant deep-level peaks of the samples grown on different substrates are different. The study is based on the origin of the observed deep levels.

Methods that will improve performance of the multiquantum well stack in optical modulator devices based on quantum-confined Stark effect can be found from observing that effective mass of the active quantum well material is significantly smaller in the conduction band than in the valence band. Significant improvements could then be likely to be found in the overall performance of the devices that likely would be achieved by engineering the band alignment of quantum well and barrier to accommodate differences in effective masses. A band-alignment strategy for efficient optical modulation in quantum-confined Stark effect devices is presented.

Contactless electroreflectance, in the range of 18

The dependence of the room-temperature (RT) absorption coefficient on nitrogen fraction in Ga[As.sub.1-x][N.sub.x] and [Ga.sub.1-y][In.sub.y][As.sub.x][N.sub.1-x] alloys is examined. The discrepancy between the measured and calculated absorption coefficient at threshold has shown that a proper description of the near-gap optical properties of dilute nitride alloys should go beyond the effective mass approximation.

Hybrid ferromagnetic-semiconductor GaP:MnP thin films are grown by metal-organic vapor phase epitaxy on GaP(001) by using trimethylgallium, tertiarybutylphosphine and methyl cyclopentadienyl manganese tricarbonyl (MCTMn). Magnetometric characterization has shown a ferromagnetic order, with a Curie temperature of about 294 K, which has originated from the MnP clusters.

A study on photoluminescence (PL), PL excitation (PLE), and time-resolved PL (TRPL) of GaAsN epilayers grown by metal-organic vapor phase epitaxy (MOVPE) is presented. The results reveal the origin of the near-gap emission band observed in the sample at an energy position that varies between 18 and 28 meV below the GaAsN band gap.

The bonding properties of amorphous silicon oxynitride (SiO(sub x)N(sub y)) films deposited at low temperatures (LTs) by electron-cyclotron resonance chemical-vapor deposition (ECRCVD) on several substrates and under various conditions of gas flows and total gas pressure in a dilute mixture of SiH(sub 4)+N(sub 2) in Ar was established using tetrahedral model. The Si(sub 3)N(sub 4) phase is the most important one and the only bonding unit that is incorporated in all LT ECRCVD SiO(sub x)N(sub y) films.

An extension of the random mixture model (ERMM) is developed to study the bonding properties of amorphous-SiOxNy films. Based on this ERMM, the relative atomic percentage of each tetrahedral phase incorporated in the film network is obtained from the deconvolution of the high-resolution x-ray photoelectron spectroscopy spectra in the Si 2p(sub 3/2) region.

Nanocavities formed in InP (001) by He implantation at room-temperature and subsequent thermal annealing was studied with high-resolution x-ray diffraction and cross-sectional transmission electron microscopy analyses. The results are compared with other similar works on He-implanted silicon.

Provides information on an experimental study observing time-resolved differential reflection in InAsxP1-x/InP (x...0.35) strained-multiple-quantum wells using the pump-probe technique. Methodology used to conduct the experiment; Results of the experiment; Information on the model calculations; Discussion on the results.

The origin of the unintentional incorporation of O, and its effect on the SiN(sub X) film properties for an electron-cyclotron resonance chemical-vapor deposition (ECR-CVD) were studied, using a diluted SiH4 + N2 mixture in Ar. The result shows a decrease of the film compressive stress when the N2/SiH4 flow ratio increases due to the increase of Si-N bonds in detriment of N-H bonds.

Scanning tunneling microscopy (STM), atomic force microscopy (AFM), and x-ray reflectivity (XXR) was used to investigate the effects of varying tetha(sub H) on surface morphological evolution during Si(sub 0.7) Ge(sub 0.3) growth on Si(001) by GS-MBE at temperatures T(sub s)=450, 500, and 55 degrees Celsius and thinknesses t up to the critical value for misfit dislocations. The differences in surface morphological evolution observed suggests that tetha(sub H) plays an important role in mediating the kinetics of strain-induced roughening through changes in film growth rates as well as adatom mean-free paths and step-crossing probabilities.