[en] The symposium organizers attempted to include a fairly comprehensive overview of the subject of beam solid interactions. The majority of the presentations dealt with ion beams, but there were a significant number of papers on the subjects of photon and electron interactions as well. The scope of the symposium was intended to cover the range from the basic physics of beam solid interactions to a wide variety of current and emerging applications of beam techniques. The symposium included materials of virtually all classes from electronic and optical materials to metals and ceramics. The papers in this volume have been divided into ten categories covering the scope of the symposium. The first section covers the basic physics of beam solid interactions through computer simulations and calculations. This is followed by a section on high energy interactions mainly through electronic excitation. The third and fourth sections are the largest and cover radiation damage and implantation. The papers in this subject have been divided according to material systems. One section deals with electronic and optical materials, while the second covers metals, ceramics, and other materials. A section on beam induced amorphization and recrystallization then follows. Papers on finely focused beams and the issues associated with fine scale patterning have been grouped together in the next section. The remaining sections cover ion beam deposition, laser processing, sputtering and etching, and mesotaxy. Separate abstracts were prepared for 138 items in this conference

[en] Energy absorption of intense Nd:YAG laser pulse at the surface of aluminum was measured as a function of laser energy fluence φ by photoacoustic 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. Photoacoustic 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 φ_th. When the φ was lower than the φ_th, the I was constant and corresponded to the absorption coefficient of the metal. Above the φ_th, it approached the maximum I_max and then began to decrease with further increase in the φ. If the authors represent the relative change in I at different pulse energies as the normalized intensity I/I_max, a universal curve was obtained. Below the φ_th, the process was normal photon absorption by the metal. Damage left on the irradiated surface became evident above the φ_th. Above the φ_th and below the I_max, 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 I_max, some processes which inhibit the energy absorption would occur and the I would decreased

[en] 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 predeposited 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 nonequilibrium phases, including amorphous materials. Improved surface properties, including tribology and corrosion resistance, are observed in these materials. 65 refs., 9 figs

[en] Single crystals and epitaxial films of SiC - 4H and 6H were implanted at an energy of 40 and 90 KeV by ions of Al at various temperatures and high dose. The implanted layers were studied before and after annealing by Raman scattering, Auger electron spectroscopy and SIMS. Results of this investigation show intensive graphitization of the implanted layer surface, the formation of great associations of defects in the implanted layer and shallow defects. It was found that recrystallization of the implanted layer pushes out a considerable part of aluminum atoms. The nature of the processes in silicon carbide during implantation and annealing is discussed

[en] Two-dimensional electron gas 60--120-nm deep from the surface was irradiated with 10-keV Ar ions (projected range = 8.8 nm) and resulting change in the mobility was analyzed. Defect distribution thus obtained is exponential in depth with the larger penetration length for the lower irradiation temperature. In-situ Hall measurements revealed that the mobility decreases simultaneously with the irradiation at 90 K. Consequently, the deep penetration of defects is concluded to be mainly due to the ion channeling. Results of iso-chronal annealing indicate that thermal diffusion of the defect that affects the mobility takes place at around 340--400 K, whereas the mobility starts to recover at ∼120 K

[en] In the p-type shallow junction formation using B⁺ implantation, preamorphization is an essential technique to suppress B⁺ channeling. The crucial problem in this process is defect formation at an amorphous-crystal(a-c) interface. The authors have demonstrated that MeV ion implantation is effective to reduce defects for shallow junction formation. F⁺ preimplantation at 40 KeV with 1 x 10¹⁵ cm^-2 was effective to form P-type shallow junctions by B⁺ implantation at 10 KeV with 5 x 10¹⁵cm^-2. However, defect formation induced boron diffusion and also leakage current increase. These problems were overcome by MeV ion implantation at 1 MeV F⁺ or Si⁺ with 5 x 10¹⁵ cm^-2, followed by rapid thermal annealing at 1,000--1,100 C for 10 seconds. In the F⁺ preimplanted samples, followed by MeV ion implantation, defects at the a-c interface can be reduced and an about 50% shallower junction depth was obtained, compared with just B⁺ implanted samples. The results indicate that MeV ion implantation is effective to form a shallow junction with a low leakage current

[en] The effects of Si and Kr ion implantation on the crystallization kinetics of amorphous CoSi₂ have been investigated by differential scanning calorimetry and in situ sheet resistance measurement. Without ion implantation, the crystallization of coevaporated CoSi₂ is characterized by three dimensional growth from preexisting nuclei. When the as-deposited CoSi₂ is implanted with Si or Kr ions at liquid nitrogen temperature, the kinetics of the subsequent crystallization is significantly altered. A 180 keV 5 x 10¹⁵cm^-2 Si ion implantation increases the crystallization temperature by 34 C. When the Si dose is below 1 x 10¹⁵ cm^-2, ion implantation causes a sharp decrease in the crystallization kinetic parameter defined by the Avrami equation. The amount of decrease is shown to scale with the deposited nuclear energy. At higher doses, the kinetic parameter continues to decrease with increasing dose but at a much reduced rate

[en] 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(111) 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

[en] 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. In this paper, the feasibility of processing condensed precursors such as diborane, tri-methyl aluminum, ammonia and water at 78 K with low energy (100--1,000 eV ) electron and ion beams (Ar⁺, N₂⁺ and H₂⁺) ranging in current density from 50 nA to several μa 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

[en] Electron cyclotron resonance (ECR) argon plasma has been used to etch the native oxide on Si and thermal SiO₂. The Schottky barrier height modification on both n and p-Si has been studied as a function of substrate bias and etch time. Deep Level Transient Spectroscopy (DLTS) measurements show clear peaks on both p and n-Si, but with low levels of trap concentrations (10¹²-10¹³ cm^-3), and decreasing with depth from the surface. The effects of thermal oxide etching on the Si/SiO₂ interface have been estimated with MOS capacitors. Negative flat-voltage shift is observed after argon plasma exposure, which removes the thermal oxide at a rate of over 100 angstrom/min at 50 V bias. C-V measurements show an order of magnitude increase in interface trap density