A novel gas source replacing fluorocarbon feed gases has been developed for preventing global warming. The novel gas source was designed to generate fluorocarbon species from polytetrafluoroethylene by CO2 laser ablation. The species generated from the gas source were introduced into an electron cyclotron resonance (ECR) plasma employing Ar gases. To characterize the gas source, CFx (x=1–3) radical densities with and without plasmas were measured by infrared diode laser absorption spectroscopy. In the ECR plasma employing the novel gas source, CFx (x=1–3) radical densities were estimated to be of the order of 1012–1013 cm-3. The gas source has been applied to the selective etching of SiO2 to Si using the ECR plasma. As a result, the etching characteristics by ECR plasma employing the novel gas source were equivalent to those by a conventional ECR plasma employing C4F8 gas. Therefore, this novel gas source is applicable to etching processes for preventing global warming. © 1999 American Vacuum Society.