ELECTRON-BEAM EFFECTS ON (CH2)17 SELF-ASSEMBLED MONOLAYER SIO2/SI SPECIMENS

This paper examines die damage created by an electron beam on layered specimens consisting of a (CH2)17 self-assembled monolayer (SAM) deposited on an oxidized Si wafer. Beam effects on both the SAM and substrate were observed. X-ray photoelectron spectroscopy (XPS) measurements indicate that less than 20% of the carbon from the film is lost during the beam damage, ion analysis shows hydrogen emission from the films, and residual gas analysis suggest loss of some CH(x) (x = 2 - 4) molecules. Consistent with the conversion of some (CH)n chains to ''graphite,'' the C 1s photopeak is broadened by die electron bearn. In addition to the effects on the SAM layer, there are shifts for the O 1s and oxidized-Si2p binding energies due to die electron beam exposure. Studies on SiO2 filMS formed in a wide variety of ways, without the SAM, show similar effects. These shifts are attributed to changes in potential at the Si-SiO2 interface.