Monoalkoxysilanes and dialkoxysilanes and dense organosilica films made therefrom

A method for making a dense organosilica film with improved mechanical properties, the method comprising the steps of:

• providing a substrate within a reaction chamber;
• introducing into the reaction chamber a gaseous composition comprising at least one mono- or dialkoxysilane having the structure given in Formula (1) or (2):
• HR1R2SiOR3 (1)
• wherein R1 is methyl, R2 is selected from a branched or cyclic C3 to C10 alkyl, and R3 is selected from a linear, branched or cyclic C1 to C10 alkyl;
• R4R5Si(OR6)2 (2)
• wherein R4 is hydrogen or methyl, R5 is selected from a linear, branched or cyclic C1 to C10 alkyl, and R6 is selected from a linear, branched, or cyclic C3 to C10 alkyl, wherein at least one of R5 and Re is either a cyclic C3 to C10 alkyl or a branched alkyl and wherein if R6 is iso-propyl or sec-butyl then R4 is methyl;
• and
• applying energy to the gaseous composition comprising the at least one mono- or dialkoxysilane in the reaction chamber to induce reaction of the gaseous composition comprising the at least one mono- or dialkoxysilane to deposit an organosilica film on the substrate, wherein the organosilica film has a dielectric constant of from about 2.80 to about 3.30 and an elastic modulus of from about 7 to about 30 GPa.