Deposition of Ge-doped silica thin films for an integrated optic application using a matrix distributed electron cyclotron resonance PECVD reactor

Abstract

Optical quality Ge-doped SiO2 thin films, suitable for an integrated optic version of a gain equalizer for erbium-doped fibre amplifiers (EDFAs), have been deposited using a matrix distributed electron cyclotron resonance plasma-enhanced chemical vapour deposition (MDECR-PECVD) system. Using spectroscopic ellipsometry and infrared transmission spectroscopy, the optical constants and hydroxyl content of the films were calculated. Losses due to the hydroxyl overtone at 1.37μm are found to be approximately 0.251dB/cm. An RBS analysis determined the germanium content of the films to be in the vicinity of 4 at.%. A comparison of the atomic percentage of germanium in the films and their corresponding refractive indices with values obtained using other deposition methods is also discussed.