Electron and ion beams can be used to deposit thin films and etch surfaces using gas phase precursors. However, the generation of undesirable gas phase products and the diffusion of the reactive species beyond the region irradiated by the electron or ion beam can limit selectivity. Tn this paper, the feasibility of processing condensed precursors such as diborane, tri-methyl aluminum, ammonia and water at 78 K with low energy (100–1000 eV) electron and ion beams (Ar+, N2+ and H2+) ranging in current density from 50 nA to several μ a per cm2 is examined. It was found that boron, boron nitride and stoichiometric aluminum oxide films could be deposited from the condensed volatile species using charged particle beams and some of the physical and chemical aspects and limitations of this new technique are discussed.

Initial experiments on the evaporation from metallic and ceramic targets using a pulsed light ion beam source is reported. The source is an intense ion beam produced by a 1.2 MV, 300 kJ Anaconda generator which has been fitted with an extraction diode.

Beam fluences of 10–20 J/cm2 give a deposition rate of about 30–50 nm per shot, for both brass and YBa2Cu3O7-x (1–2–3) targets. This is about 1000 times greater than comparable rates from pulsed laser deposition (PLD). Single-shot ablated 1–2–3 films, deposited on Si, were analyzed using RBS; the measured stoichiometry was close to 1–2–3 in favorable cases, but shot-to-shot reproducibili ty was poor.

Approximately 1% of the available ion beam energy was utilized for these initial experiments. The potential for producing large area coatings from multi-cation targets and nanophase powders using pulsed ion beam deposition will be discussed.

Surface modification can improve materials for structural, tribological, and corrosion applications. Excimer laser light has been shown to provide a rapid means of modifying surfaces through heat treating, surface zone refining, and mixing. Laser pulses at modest power levels can easily melt the surfaces of many materials. Mixing within the molten layer or with the gas ambient may occur, if thermodynamically allowed, followed by rapid solidification. The high temperatures allow the system to overcome kinetic barriers found in some ion mixing experiments. Alternatively, surface zone refinement may result from repeated melting-solidification cycles.

Ultraviolet laser light couples energy efficiently to the surface of metallic and ceramic materials. The nature of the modification that follows depends on the properties of the surface and substrate materials. Alloying from both gas and pre-deposited layer sources has been observed in metals, semiconductors, and ceramics. Surface enrichment of Cr by zone refinement of stainless steel has also been seen. Rapid solidification after melting often results in the formation of non-equilibrium phases, including amorphous materials. Improved surface properties, including tribology and corrosion resistance, are observed in these materials.

In the present work a novel approach to suicide and nitride formation on the surface of silicon single crystals wafers is reported. The compound growth occurs directly in the place of interest as a result of a laser promoted chemical reaction. Results indicate that it is possible to obtain a titanium nitride layer superimposed on a titanium suicide film with a single-step laser irradiation process. The thickness of the suicide and nitride layers can be adjusted by a proper choice of the laser fluence and number of subsequent pulses.

Reflection high-energy electron diffraction with ∼200-ps temporal resolution is used to study the structural dynamics of the closed-packed surfaces of single crystals of lead and bismuth subjected to ultrafast laser heating. By monitoring the temporal evolution of the diffraction streak intensity, information is obtained on the mean-square vibrational amplitude of the surface atoms and the structural integrity of the surface. Pb(lll) is observed to superheat by ∼120 k above the bulk melting point. With increased heating laser intensity, melting is observed to occur subsequent to superheating. Superheating of Bi(0001) by ∼85 K was also observed.

The solidification of Si-As alloys induced by pulsed laser melting was studied at regrowth velocities where the partition coefficient is close to unity. The congruent melting temperatures, TO, of Si-As alloys were determined using a temperature measurement technique developed for this work, and were confirmed with TOmeasurements using three other methods. The time-resolved temperature measurement uses a thin-film platinum thermistor, below and electrically isolated from the Si-As alloy layer, to directly measure the temperature during solidification. This, combined with measurements of transient conductance of the Si-As alloy, time-resolved reflectivity and Rutherford Backscattering Spectrometry, permitted the determination of the solid-liquid interface temperature, velocity and partition coefficient, the latent heat of fusion and TO for Si - 4.5 at. % As and Si - 9 at. % As alloys.

A novel diagnostic technique for the studies of semiconductor surfaces is described. Experimental data on nonlocal modification effects in laser produced scribing, doping and annealing of ion implanted GaAs and Si are presented. Mechanisms of nonlocal structural and electric properties changes under modification are analyzed. Nonlocality phenomena are concluded to be universal for any strong modification procedure and very important for microelectronics technology.

A general model is derived for computing the temperature profile induced by multi-beam laser irradiation in a semi-infinite substrate. The model is then applied to calculate 2-beam irradiation induced temperature rise in substrate. From this model, it is possibLe to calculate the temperature profile induced by multi-beam irradiation in substrate. The calculated results show that the double-Gaussian beam has advantages of narrow temperature profile and low heat flow intensity. Flatly-topped temperature profiles can be obtained by converting the Gaussian laser beam.

The interaction of a cw argon-ion laser with the materials used in the microelectronics technology is described as a pyrolytic effect. A chemical reaction is induced between the oxide layer and the hot irradiated silicon or aluminum line. By making a cross section of the irradiated area using a focused ion beam, the formation of an unstable insulating material covering the conducting material is observed.

Melting velocities were measured in thin gold films by performing pump/probe transmission measurements using a unique picosecond excimer pump and dye laser probe. Monitoring the depth of the liquid by changes in the near psuedo-Brewster's angle transmission allowed for direct measurement of crystal/melt interfacial velocity up to 1500 m/s.

Fused silica is widely used material in window and lens applications for excimer laser processing. The transmittance of the laser beam in fused silica is attenuated approximately 40% by high fluence ArF excimer laser irradiation. The attenuation of the transmittance corresponds to the growth of an absorption band at 215nm. This phenomenon is troublesome for laser lithography. To investigate this effect, we examined the laser induced luminescence and absorption under various conditions. The 215nm absorption band was diminished by annealing at 900 °C for 2 hours in He ambient. Ke could successfully obtain good optical material, whose transmittance remains constant with increasing ArF laser(193nm) shot exposure.

Laser Solid-phase-epitaxy (SPE) of amorphous Si1−xGex layer on Si formed by the molecular beam deposition (MBD) method was successfully performed by cw-Kr laser irradiation. Laser SPE of small areas was achieved by Laser irradiations of short time durations and high power densities The strain in the Laser-SPE layers was evaluated by micro-Raman scattering. It is demonstrated that strained SiGe layers on Si can be grown in the central area of 10μm size within the area crystallized by Laser- SPE at a substrate temperature of 400°C after preannealing at 350°C for 15 to 30 minutes.

OH radicals were photochemically substituted for fluorine atoms in the teflon surface by using an ArF excimer laser light and an Al(OH)3 solution. This method is simple and can be performed in air atmosphere. In the process, the teflon film was placed on the Al(OH)3 which were dissolved in NaOH water solution; the ArF excimer laser light was irradiated the sample surface and the solution. By irradiating the laser, the surface was defluorinated by the aluminium atoms photodissociated from the Al(OH)3 solution, and the dangling bonds which were formed in the defluorinated surface combined with the OH radicals also photodissociated. The hydrophilic property of the photomodified surface was evaluated by the measurement of the contact angle with water. The defluorination and the OH radicals substitution were inspected by the XPS analysis and the ATR-FTIR measurement.

Energy absorption of intense Nd:YAG laser pulse at the surface of aluminum was measured as a function of laser energy fluence φ by pbotoacoustic method using a piezoelectric transducer. Luminescence spectra from laser induced plume were measured. A Q-switched Nd:YAG laser which generate pulses of 8 ns duration was used.

Pbotoacoustic signal intensity I increased according to the laser pulse energy at low fluences. At a constant pulse energy, the I was a function of the energy fluence φ and had a threshold φth, When the φ was lower than the φth, the I was constant and corresponded to the absorption coefficient of the metal. Above the φth, it approached the maximum I/max and then began to decrease with further increase in the φ. If we represent the relative change in I at different pulse energies as the normalized intensity I/Imax. a universal curve was obtained.

Below the φth, the process was normal photon absorption by the metal. Damage left on the irradiated surface became evident above the φth, Above the φth and below the Imax. surface temperature increased high enough to form melt and the photo-absorption coefficient would increase during one laser pulse. A shock wave would be formed at the surface and contribute to the increase of the I. Higher φ than at the Imax some processes which inhibit the energy absorption would occur and the I decreased.

Many of the advances in rapid solidification processing of metallic alloys exploit the trapping of solute which occurs at high solidification velocities. The difficulty of performing experiments which measure such high solidification velocities in metals has until now prevented accurate measurements of solute trapping in these systems. We have observed the transition from near-equilibrium solute partitioning to solute trapping during solidification at m/s velocities in aluminum alloys, and have compared the predictions of various solute trapping models. Aluminum thin films deposited on insulators were ion-implanted with Sn, Cu, Ge, and In, and were pulsed-laser melted; plane-front solidification was achieved, and regrowth velocities of 0.6 m/s to 5 m/s were measured with the transient conductance technique. Of the existing solute trapping models, the Continuous Growth Model of Aziz was found to fit the observed dependence of the partition coefficient on solidification velocity more closely than any other single-parameter model. The diffusive speed, which locates the transition from solute partitioning to solute trapping, was found to vary from 6 m/s to 38 m/s for various solutes in aluminum. We have examined correlations between the diffusive speed in the Continuous Growth Model and known alloy properties in order to allow better estimates of the diffusive speed to be made for alloy systems in which it has not been measured; the relation between the diffusive speed and the equilibrium partition coefficient will be discussed.

We have used the wet photoelectrochemical (PEC) etch process to demonstrate the selective removal of low aluminum (Al) mole-fraction AlxGa1−xAs layers from those with higher Al mole-fraction. High etch selectivity was found for δx as low as 0.05, but was found to decrease as the incident photon energy approached the energy bandgap of the desired stop-layer. The ultimate selectivity of one layer from an underlying layer was affected not only by differences in material composition, but also by the sequencing of the layers within the structure.

Cu intermediate layers (IL) by argon ion beam assisted deposition(IBAD) between substrates and Cu surface films (SF) deposited by electron-gun were made and their effect on the microstructure and properties of the Cu surface films were studied. Primary deposition variables were ion energy and substrates type. Trends in crystallographic texture, crystal-size and resistivity of Cu surface films with different IBAD layers on different substrates are significantly different. Analyzed by RBS, and XRD, the IBAD intermediate layer changed the crystallinity of Cu SF and increased the interface adhesion between the Cu SF and substrate. The experimental results shows that films with lower resistivity and better interface adhesion could be obtained by IBAD- PVD combined technique. The mechanism of crystallographic texture formation is also discussed.

Ar ion beam sputtering has been used to deposit fluoride glasses films up to a micron in thickness on silica and silicon substrates, Fluorozirconate films were found to be dark in colour, attributed to the presence of reduced chemical species. Fluoroaluminate films composed of fluorides less susceptible to reduction were clear and fluorescence from a layer doped with 2 wt% Er3+ is presented.

Dry etching can introduce defects into the material being etched. Simple expressions for both sidewall and top surface defect distributions may be obtained by assuming that the defects are introduced according to a phenomenological source function. Calculations of conductance based on these expressions are found to describe very well measurements on dry-etched wires and epilayers. Mechanisms by which defects can penetrate into the sample are discussed. The role of sample heating and defect diffusion is examined. In-situ measurements of sample temperature during a dry-etch run indicate that simple diffusion is insufficient to account entirely for the observed damage. Instead, dry-etch damage may arise from other mechanisms such as by knock-on replacement collisions, or via a channeling effect. A more complex form of diffusion may also affect the final damage distribution.

Angular distributions of the elastically scattered secondary electrons from two kinds of Cu surfaces, polished and textured by 2 keV Ar+ have been studied in the energy range from 50 eV to 2 keV. The results show that for the polished Cu surface the elastic scattering process is dominated by atomic scattering from single atoms (although, contributions from othei processes are also important). However when the textured surface was studied, new multiple peaks appeared on the angular distributions. Positions of these peaks for the various angles of incidence and primary energies indicate that their origin lies in the diffraction of the primary electrons on some kind of a polycrystalline structure. This structure is probably created by the process of recrystallization induced by ion sputtering similar to the sputtering induced crystallization process already known for some oxides and nonmetallic compounds.