Silicon-based Semiconductor Technology. Optical Communication Optical Waveguide Technology Research,

The optical communication is developing very fast, Planar lightwave circuit (PLC) devices are very important components in the optical communication system. silicon-based SiO2/SiON optical waveguide devices are widely used because they have such virtues as low waveguide attenuation, compatibility with semi-conductor technology and so on.In this paper we analyze and simulate the silicon-based waveguide, brief introductions of Beam propagation method (BPM), Effective Index method (EIM), Finite difference (FD) are presented. Then, A wide-angle finite-difference beam propagation method (BPM) with a perfect matched layer boundary condition (PML-BC) was presented. Characteristics of light propagating in a straight waveguide which is rough on the surface were simulated by using the wide angle BPM based on (2.2) Pade approximation, the effective Non-equidistant Discretization grid method was used in the calculation. The results of simulation indicate that the roughness of the surface should be limited in 300nm for the loss under 0.1dB/cm.The key point of the fabrication of integrated optical devices is to prepare the planar waveguide structure with high quality. At first thick SiO2 film on 4 inch Si wafer substrates was obtained without doping Ge, with gas mixtures of SiH4 and N2O, using Plasma Enhanced Chemical Vapor Deposition (PECVD) method. The index of SiO2 film changes continuously between 1.44—1.47, the deposition rate is among 2μm/hr ~ 10μm/hr. Then pure NH3 was added in the gas mixture, we adjusted the technical parameters and obtained thick SiON with high quality. The index of SiON film changes continuously between 1.48-1.7, the deposition rate changes among 1μm/hr ~ 4μm/hr. The microstructures and optical properties of the films are characterized by a prism coupler, a Fourier transform infrared spectroscopy (FTIR) and Atom force microscope (AFM). We studied various factors (temperature, pressure, power, gas flow) affect the index and deposition rate and then optimize growth conditions of the films. After two layers of SiO2/ SiON with different refractive are finished, the designed mask pattern is printed on the film by photolithography, then through ICP for dry etching, the waveguide structures are obtained, for example AWG/EDG we obtained.