Type of precursor and synthesis of silicon oxycarbide (SiOxCyH) thin films with a surfatron microwave oxygen/argon plasma

A. Walkiewicz-Pietrzykowska, J.P. Espinós, A.R. González-Elipe
Journal of Vacuum Science and Technology A, 24 (2006) 988-994
doi: 10.1116/1.2204927

Siliconelike thin films (i.e., $Si O_{x} C_{y} H_{z}$ ) were prepared in a microwave plasma enhanced chemical vapor deposition reactor from structurally different organosilicon precursors [i.e., hexamethyldisiloxane (HMDSO), dimethylsilane (DMS), and tetramethylsilane (TMS)]. The films were deposited at room temperature by using different oxygen/argon ratios in the plasma gas. By changing the type of precursor and the relative concentration of oxygen in the plasma,thin films with different compositions (i.e., $O ∕ C$ ratio) and properties are obtained. In general, raising the oxygen concentration in the plasma produces the progressive removal of the organic moieties from the films whose composition and structure then approach those of silicon dioxide. The deposition rate was highly dependent on the type of precursor, following the order $HMDSO ⪢ DMS > TMS$ . The polarizabilities, optical band gaps, and surface free energy of the films also depended on the thin film composition and structure. It is proposed that the Si–O bonds existing in HMDSO is the main factor controlling the distinct reactivity of this precursor and is also responsible for the different compositions and properties of the $Si O_{x} C_{y} H_{z}$ thin films prepared with very low or no oxygen in the plasma gas.

Etiquetado en:2006 A. Walkiewicz-Pietrzykowska A.R. González-Elipe J.P. Espinós Journal of Vacuum Science and Technology A