Octadecyltrichlorosilane (OTS, or n-octadecyltrichlorosilane) is an organometallic chemical. It is used in semiconductor industry to form self-assembled monolayer thin films on silicon dioxide substrates. Its structural chemical formula is CH3(CH2)17SiCl3. It is flammable, reacts violently with water, and is sensitive to air. It is corrosive and can severely damage mucous membranes. Its EINECS number is 203-930-7.
Octadecyltrichlorosilane is an amphiphilic molecule consisting of a long-chain alkyl group (C18H37–) and a polar head group (SiCl3–), which forms Self-Assembled Monolayers (SAMs) on various oxidic substrates.
Dodecyltrichlorosilane, an OTS analog with shorter alkyl chain, is used for the same purpose as well.