Investigation of the optics system carbonaceous contamination induced by chemically amplified resist outgassing under e-beam radiation

The developing multi e-beam lithography tools face important challenges in controlling the contamination of the optics system due to the deposition of hydrocarbon layer induced by the resist outgassing under e-beam radiation and high-vacuum. In this work, we present an experimental methodology allowing the investigation of the specific silicon micromachined membranes (called mimics) carbonaceous contamination induced by resist outgassing under 5keV e-beam radiation by using a dedicated experimental setup designed in CEA-Leti. The Focus Ion Beam combined to Scanning Electron Microscopy (FIB-SEM) and X-ray Photoelectron Spectroscopy (XPS) characterization techniques were used to determine the contamination layer thickness and elementary composition, respectively. A first process-oriented conclusion from this work shows that the contamination layer growth depends on e-beam current density and induced precursor pressure in the vicinity of the mimics.