Sputtering of thin organic layers

Laser postionization technique has been used to investigate processes that occur during ion bombardment of thin organic layers. Dependence of the kinetic energy distributions has been investigated as a function of layer thickness and projectile type. Thin films obtained from self-assembled monolayer of phenylethanethiol on gold and C₆H₆ on silver have been probed. Results indicate that the sputtering mechanism depends on the organic material used. Phenylethanethiol molecules are emitted predominantly with thermal kinetic energies and the shape of the distribution depends on surface temperature. Emission of benzene is much more energetic and possesses characteristics similar to sputtering of metals. Emission of phenylethanethiol molecules is stimulated by a chemical reaction, which gently breaks the adsorbate surface bonds. Benzene molecules are emitted from the thin overlayer due to collisions with ejecting substrate atoms.