We report on the fabrication and characterization of silicon oxynitride (SiON) layers for applications as planar optical waveguides in the 1550 nm wavelength region. The optically guiding SiON waveguide core layer has a relatively high refractive index of 1500 and is sandwiched between two silicon oxide cladding layers with a lower refractive index of 1450. The SiON layer is deposited by plasma‐enhanced chemical vapor deposition using silane, nitrous oxide, and ammonia as gaseous precursors. Waveguide bends with a radius of curvature as small as 1.5 mm can be realized because of the high refractive index difference achievable between core and cladding layers. This allows the fabrication of compact, relatively complex integrated optical waveguide devices. The deposition process and the characterization of the SiON films are discussed. The strengths of this high refractive index contrast planar waveguide technology are illustrated using the example of an optical add/drop filter for wavelength division multiplexing applications in the field of optical communication systems. © 2000 The Electrochemical Society. All rights reserved.

No abstract

No abstract

No abstract

In this work we investigate doping by solid-state diffusion from a doped oxide layer, obtained by plasma-enhanced chemical vapor deposition (PECVD), as a means for selectively doping silicon nanowires (NWs). We demonstrate both n-type (phosphorous) and p-type (boron) doping up to concentrations of 10(20) cm(-3), and find that this doping mechanism is more efficient for NWs as opposed to planar substrates. We observe no diameter dependence in the range of 25 to 80 nm, which signifies that the NWs are uniformly doped. The drive-in temperature (800-950 °C) can be used to adjust the actual doping concentration in the range 2 × 10(18) to 10(20) cm(-3). Furthermore, we have fabricated NMOS and PMOS devices to show the versatility of this approach and the possibility of achieving segmented doping of NWs. The devices show high I(on)/I(off) ratios of around 10(7) and, especially for the PMOS, good saturation behavior and low hysteresis.