Evaluation of halogenated polyimide etching for optical waveguide fabrication by using inductively coupled plasma

Oxygen plasma etching of a series of halogenated polyimides was carried out for low-loss waveguide fabrication by using inductively coupled plasma (IC P). The effects of etching parameters such as ICP power, rf power, and O-2 flow rate on the etching rate and etching profile of polymer films were inv estigated. The increase in the etch rate with the ICP power and the rf powe r was observed. Both the vertical pro file and sidewall roughness were foun d to be related to the ion energy (dc bias). By optimizing these parameters , a vertical profile and a smooth sidewall were obtained by 500 W of ICP po wer, 150 W of rf power, 5 mTorr of chamber pressure, and 40 seem of the O-2 flow rate. (C) 2000 John Wiley & Sons, Inc.