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This paper presents the investigations of thin dielectric silicon oxide (SiOx) and silicon nitride (SiNx) films deposited below 100 °C by a plasma enhanced chemical vapour deposition (PECVD) using an inductively coupled plasma (ICP)‐source. The influence of the deposition pressure and the applied RF‐power to the plasma from the ICP‐source and a second RF‐power at substrate electrode on the characteristics of the deposited films are studied. The investigated characteristics are refractive index R.I. at 632 nm, deposition rate Rdep, stress σ and etching rate Retch in buffered hydrofluoric acid (BHF). Measurements from electron spectroscopy for chemical analysis (ESCA) support the investigations. The results are discussed and compared with other PECVD deposition methods. A significant influence of the RF‐generator connected to substrate electrode on etching rate and hence on film quality is identified for SiOx but the converse effect is identified for SiNx‐films.

We present the characterization of silicon oxide (SiO x ) and silicon nitride (SiN x ) films deposited by inductively coupled plasma chemical vapour deposition (ICP-CVD) at low temperature (< 100 • C). A tunable optical FabryPérot (FP) -filter operating at a wavelength around 1.5µm is realized. It is hybridly assembled with two dielectric distributed Bragg reflectors (DBR). One of the DBR-mirrors is intentionally curved using the intrinsic stress inside the films. Our aim is the development of a tunable surface micromachined VCSEL with a curved dielectric mirror. Therefore ICP-CVD with a low deposition temperature is used for SiO x and SiN x films. As a first step the realization of a tunable bulk-mircomachined optical FP-filter is presented. The refractive index, deposition rate, stress and etching rate in buffered hydrofluoric acid (BHF) of thin dielectric films (<500 nm) in dependence on deposition temperature and on gas flow ratio are investigated. The knowledge of the deposition characteristics of the dielectric films is used to realize DBRs with a given curvature that are applied to electrothermally actuated, optical tunable FP-filters. The presented filter has a free spectral range of 29 nm, an insertion loss of 10 dB and a full width half maximum of 0.16 nm.

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