A microlens fabrication process is described which can be used in applications requiring integration of optical elements (lenses) and microcircuits. The process is fully compatible with 1C fabrication technology and uses commercially available 1C processing materials. The obtained microlenses are of excellent quality and basically show diffraction-limited resolution with ~1-microm spot size. Extensions of the process to production of nonspherical lenses and use of alternative material packages are also discussed.

Epitaxial yttria-stabilized zirconia films were grown on Si (100) and Si (111) by pulsed laser deposition. Rutherford backscattering spectroscopy indicates a high degree of crystalline perfection with a channeling minimum yield of 5.3%. A necessary predeposition process is removal of native silicon oxide from the Si prior to film growth. This is done outside the deposition chamber at 23 °C using a wet-chemical hydrogen-termination procedure. Epitaxial YBa2Cu3O7−δ films have been grown on these films.

The structure of evaporated As2S3, As, Se"and GeSe, films, and the influence of annealing at the glasstransition temperature, are studied by extended x-ray-absorption fine structure (EXAFS) and by Raman spectroscopy. In addition, the topology of each film is analyzed by calculating the x-ray diffraction for several models. The films were prepared by evaporation onto sub~irates held near room temperature. All the as-deposited films exhibited significant homopolar bonding in contrast to the almost totally heteropolar bonding of the corresponding bulk quenched glasses. Upon annealing of.the films, the measurements indicate that the density of homopolar bonds decreases, and the films more closely resemble the bulk quenched glasses. The Raman spectra are quantitatively analyzed with two models to characterize the disorder, and then compared to the EXAFS results. The analysis indicates an As-As coordination of -0.6 and -0.4 and a Ge-Ge coordination of -0,3 for the As, S3, As, Se"and GeSe, as-deposited films, respectively. The measurements also indicate that the As-As bonds of the As, S, film are incorporated into S,As-AsS, units, suggesting the presence of As4S4 molecules. Calculations using this model are in good agreement with x-ray diffraction data in the literature. The data from As, Se3 evaporated films also indicate that molecular structures may be present. There is no evidence, however, for molecular structures in GeSe, films.

A new method of obtaining Raman spectra from a very thin highly absorbing films (α≳105 cm−1) is described. The technique which is termed interference enhanced Raman scattering (IERS) is shown theoretically to produce a gain in the scattered intensity of 10–103 (depending on the optical constants of the material) over that expected from a thick sample using the conventional Raman backscattering configuration. The potential of the method is demonstrated experimentally using tellurium, and a gain of 20 is obtained.

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