Composition and Electrical Properties of Metallic Ru Thin Films Deposited Using Ru(C6H6)(C6H8) Precursor

Metallic ruthenium films were prepared by metalorganic chemical vapor deposition (CVD) using a new precursor named (η6-benzene)(η4-1,3-cyclohexadiene)ruthenium (Ru(C6H6)(C6H8)) in Ar atmosphere, and the absolute composition and electrical properties were investigated. The absolute composition including hydrogen was determined by means of the elastic recoil detection time of flight (ERD-TOF). It was found that carbon contents in the films markedly decreased when tetrahydrofuran (THF) was supplied with the precursor during deposition. The variation in carbon content could be interpreted by the formation of hydrocarbon compounds as well as the formation of carbon oxide, resulting from the reaction between carbon and THF. In particular, Ru films contained hydrogen that originated in the hydrogen atoms in the precursor and was involved in the CVD process due to the catalytic effect of ruthenium on hydrocarbon and hydrogen. It was shown that grain size, among several other factors strongly affected the electrical properties of ruthenium films.