The refractive index of silicon oxynitride (SiON), a widely used material for integrated optics df,ices, can be chosen in a wide range between 1.45-2.0, Wie describe how the consequent large design freedom can be exploited on the one hand for a "standard" polarization independent optical channel waveguide having a favorable tradeoff between efficient fiber-chip coupling and small bend radii (compact devices) and on the other hand for special-purpose and hybrid components where the refractive index should be finely adjusted for obtaining the desired functionality. We illustrate the applicability of SiON by describing a few devices for optical filtering in a new architecture for wavelength multiplexing, modulation, polarization splitting and second-harmonic generation.

Surface roughness is one of the crucial factors in silicon fusion bonding. Due to the enhanced surface roughness, it is almost impossible to bond wafers after KOH etching. This also applies when wafers are heavily doped, have a thick LPCVD silicon nitride layer on top or have a LPCVD polysilicon layer of poor quality. It has been demonstrated that these wafers bond spontaneously after a very brief chemical mechanical polishing step. An adhesion parameter, that comprises of both the mechanical and chemical properties of the surface, is introduced when discussing the influence of surface roughness on the bondability. Fusion bonding, combined with a polishing technique, will broaden the applications of bonding techniques in silicon micromachining.

The thickness non-uniformity and refractive index in-homogeneity of silicon oxynitride thin films, grown by low pressure chemical vapor deposition, have been optimized. The present work was especially motivated by the application of these thin films as well defined waveguides in phase-matched second harmonic generating devices, which are well known for their extremely high requirements to uniformity and homogeneity. However, other demanding integrated optical components like gratings, sensor systems,telecommunication devices, etc., also strongly benefit from highly uniform waveguides.

Silicon oxynitride layers grown by Low Pressure Chemical Vapor Deposition have been optimized towards high uniformity in thickness and refractive index. These layers have been applied as passive waveguides in phase-matched second-harmonic generating devices .

Phase-matching (TM0ω → TM12ω) devices for generation of blue light using Si[O]N and optically nonlinear calix[4]arene layers are designed, fabricated and tested. The devices show second harmonic peak power of 17 mW at 472.9 nm and 4.5 W at 481.6 nm after 10 mm propagation length of a 1 mm broad beam using fundamental peak power of 200 W and 500 W, respectively. The strong requirements of noncritical phase match are fulfilled, in both design and realization, by the excellent process controllability of the passive Si[O]N waveguides and the insensitivity of the devices towards technologically critical parameters, mainly the calix [4]arene layer thickness.

A mode-size adapter was designed, fabricated in SiON/SiO/sub 2/ and tested. It consists of a laterally tapered SiON waveguide having a step-wise decrease in thickness towards the taper point which may have up to 0.5 /spl mu/m residual width.

The hydrogen in PECVD-SiOxNy was studied with IR spectroscopy and ERD analysis as a function of the O/N ratio and the annealing treatment up to 1150°C. The results were compared with measured spectral waveguide losses

A signal enhancement of 10 dB at 1535 nm with a low launched pump power of 1 mW at 1480 nm is achieved for sputtered Er3+:Y2O3 channel waveguides on oxidised silicon substrates. With the developed reactive co-sputtering process using sputterguns the erbium concentration can be varied easily and reproducibly.

Zinc sulphide thin films have been deposited with CART using zinc chlorideand zinc acetylacetonate as Zn compounds and thiourea and 1,1,3,3-tetramethylthiourea as S compounds soluted in methanol, ethanol, isopropanol and cellosolve. After optimalization of the deposition process homogeneous layers with a c-axis oriented hexagonal columnar structure with a high density (up to 96%) were obtained. Luminescence was observed with films grown above 500°C. The influence of the hot plate temperature, flow of carrier gas, nozzle geometry, distance nozzle substrate, and volatility of the solvent and reactants on the growth rate, homogenity and density of the film has been shown. Some rules for the selection of the starting compound are given. TG analyses of the reactant compounds was used to compare their volatility and stability.

Fine-grain thin superconducting films can be prepared by metalorganic Chemical Aerosol Deposition Technology (CADT). In this paper, we present the preparation and properties of YBa2Cu3O7-x films on the different substrates, Si and SrTiO3 (100). It is shown that the zero-resistance temperature (Tc,0) of the films on SrTiO3 substrates is about 90 K, and the critical current density (Jc) at 77 K is above 104 A/cm2. In addition, these films exhibit significant grain-boundary weak link behaviour, which is very promising for applications in electronic devices.