Recently coating of silicon oxide films onto polymer has been strongly needed, so that plasma-enhanced chemical vapor deposition (PECVD) using organosilicon compounds, which is possible to lower process temperature, has been extensively studied. At present, however, the deposition mechanism of silicon-oxide films at low temperature is not clear. In this study we investigated the behavior of organosilicon molecules in rf-PECVD of silicon oxide films using two kinds of diagnosing techniques, mass analysis of gas species in the plasma and in situ IR absorption measurement on the film surface.

We used an inductively-coupled rf PECVD system. After the evacuation below 1 Pa, tetramethoxysilane (TMOS) gas was introduced into the chamber. The pressure of TMOS and the rf power were kept at 10 Pa and 50 W. We used a quadrapole mass spectrometer (QMS) to analyze the gas in the plasma sampled through a pinhole on the substrate holder. In situ observation of film surface was carried out by a Fourier transform infrared spectrometer (FT-IR).

We observed a reduced fragmentation pattern of TMOS gas in the plasma when the ionization part of QMS was activated. The intensity of the peak at m/e=152, mass number of TMOS molecule, was 1/100 compared with that of same peak without discharge. This fact means that the 99% of TMOS molecules are modified in the plasma. The ions generated in the plasma was measured directly by inactivating the ionization part of QMS. In the mass region of m/e>152, some discrete peaks were observed clearly. Polymerization of reactant molecules and their fragments occur in the vapor phase.

Improvements in the performance of precision optical coatings have led to their increasing acceptance in a variety of light-filtering applications. For example, the development of environmentally-stable filters in the past decade resulted in widespread use of such coatings in medical and aerospace instrumentation. Recently environmentally-stable filters possessing unprecedented spectral performance have been demonstrated. This extension of the technology has led to the use of precision optical coatings for extremely demanding applications such as dense wavelength division multiplexing (DWDM) telecommunication systems.

DWDM systems employ multiple optical carriers at different wavelengths which are combined for transmission over the same optical fiber. One popular method for combining and separating wavelenghts in DWDM system is based on the transmission and reflection characteristics of interference filters. The spectral requirements for DWDM devices are very demanding and result in challenging filter specifications with regard to spectral shape and wavelength positioning. Additionally, DWDM devices must operate over wide temperature ranges and be compatible with a variety of devices such as optical amplifiers. This paper reviews new requirements for precision optical coatings, with an emphasis on those used in DWDM applications, and details the excellent performance which is achievable.

We present the results of a systematic spectroellipsometric and conductivity study of metallic nitride (mostly TiN) thin films prepared by the ion-beam-assisted deposition technique. We correlate the dc resistivity with the contactless, noninvasive ellipsometric method of extracting the free- and bound-carrier response in the infrared, visible, and ultraviolet spectral ranges. We find the optimum conditions for the ellipsometric measurements, and demonstrate the potential of the technique on several series of the filmed samples grown at varying substrate temperatures and ion-beam energies. The high polarizibility of free carriers at optical frequencies presents nontrivial problems of the optimization. We discuss the relative merit of the ellipsometric data taken at proper angles of incidence in different spectral ranges, aiming at the maximized precision and accuracy of the sought film parameters.

We also test the algorithms of fast parameter retrieval for the use in in-situ measurements. The implications of the trial to replace the spectroellipsometric data with single- or double-wavelength laser measurements in the in-situ environment, aiming at the increased speed and simplified data treatment, are discussed. Finally, we address the issue of optimum data sampling during the growth of both homogeneous and graded TiN films on silicon.