Anomalous Roughness Scaling of Well‐Ordered Amorphous Fluorocarbon Films Deposited from an Octafluorocyclobutane Plasma

Fluorocarbon thin films with adjustable surface roughness are deposited in a capacitively coupled octafluorocyclobutane (c‐C4F8) plasma at a pressure of 40 Pa and 100 Pa. The surface morphology is studied using non‐contact atomic force microscopy (AFM). The film properties are analyzed using spectroscopic ellipsometry (SE) and Fourier transform infrared spectroscopy (FTIR). The interface roughness w of the 100 Pa deposition rapidly increases with deposition time t according to a power law w ~ t^β with a dynamic scaling exponent β of 1.35 ± 0.08. This large β‐value indicates anomalous roughness scaling. Different growth models are discussed which might explain the rapid roughness evolution that is observed during high pressure deposition. magnified image