Electron-beam-induced deposition of carbon films on Si(1 0 0) using chemisorbed ethylene as a precursor molecule

Abstract

We studied the electron-beam-induced deposition of carbon on Si(1 0 0) at room temperature. Ethylene molecules dosed from the background were adsorbed on the surface and decomposed by an electron-beam. The chemical properties and structure of the resulting carbon film, as well as its evolution with the dose of ethylene and annealing temperature after dosing, were investigated by Auger electron spectroscopy (AES) (line-shape analysis), by X-ray photoelectron spectroscopy (XPS) and by temperature-programmed desorption (TPD). Additionally, the amorphous-like hydrogenated carbon structure obtained after electron-beam-induced deposition (EBID) converted completely into SiC upon annealing to ∼1150 K as evidenced by the shift of the Si(2p) plasmon loss peak and the C(1s) peak. We also show that C–H bonds in ethylene are cracked by electron bombardment and that some of the hydrogen atoms produced from cracking are captured. The EBID of carbon was also compared with the chemical vapor deposition of ethylene on Si(1 0 0) in the absence of an electron-beam and a more stable carbon structure can be formed by EBID. It is postulated that EBID deposition produces an amorphous hydrogenated film which contains a high fraction of multiple carbon-carbon bonds, compared to films made by thermal decomposition of the ethylene precursor. This leads to a higher conversion temperature to SiC.