Bonding Structure of Model Fluorocarbon Polymer Residue Determined by Functional Group Specific Chemical Derivatization

Using FTIR, XPS and SEM, the bonding structure of model fluorocarbon polymer residues (6-28 nm) deposited on 90 nm low-k dielectric trench lines was determined to consist of amorphous fluorinated polymers with significant branching, C=C and C=O functional groups. The carbonyl functionality was identified by 2,4-dinitrophenylhydrazine derivatization. The olefinic linkages with various degrees of fluorination was established by Br-2 addition to C=C bonds in model fluoropolymer. Reductive defluorination of C-F bonds was carried out using naphthalenide radical anion treatment. Adding O-2 and NF3 to CHF3/C4F8/Ar plasma changed coating profiles and resulted in a disproportionate decrease of carbonyl and olefinic functionalities. (C) 2013 The Electrochemical Society. [DOI:10.1149/2.008303ssl] All rights reserved.