AVS 46th International Symposium
    Plasma Science and Technology Division Monday Sessions
       Session PS-MoP

Paper PS-MoP14
CF@sub x@ Radical and Etch Product Concentrations in Fluorocarbon Plasmas from Tunable Infrared Diode Laser Spectroscopy

Monday, October 25, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: Y. Men, University of Wisconsin, Madison
Authors: Y. Men, University of Wisconsin, Madison
I.C. Abraham, University of Wisconsin, Madison
R.C. Woods, University of Wisconsin, Madison
Correspondent: Click to Email
A sensitive diode laser spectrometer using multi-pass Herriot cells was employed in both an ECR etcher (30 passes with approximately 30 cm plasma depth) and in a 10 cm diameter, 1 m long hollow cathode DC discharge (46 passes). An IR diode laser operating near 1260 cm@super -1@ was used to study the CF@sub x@ (x = 1,2,3) radicals. Both CF and CF@sub 2@ were easily identified in a CF@sub 3@H ECR plasma, and their absolute concentrations were determined. Other fluorocarbon plasmas, e.g., C@sub 2@F@sub 6@ and C@sub 4@F@sub 8@, have also been investigated. The CF@sub x@ radical concentration dependences on plasma parameters, e.g., input power and neutral pressure, and on the partial pressure of added gases have been studied. To simulate actual etching conditions, radical concentrations over different wafer surfaces and at various bias powers have been measured. The CF@sub x@ concentrations with different reactant gases in the ECR etcher have been compared to those in the hollow cathode discharge. A diode laser operating in the 800-900 cm@super -1@ region is being used for similar investigations of SiF@sub x@ etch products.