Described herein are low temperature processed high quality silicon containing films. Also disclosed are methods of forming silicon containing films at low temperatures. In one aspect, there are provided silicon-containing film having a thickness of about 2 nm to about 200 nm and a density of about 2.2 g/cm3 or greater wherein the silicon-containing thin film is deposited by a deposition process selected from a group consisting of chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), cyclic chemical vapor deposition (CCVD), plasma enhanced cyclic chemical vapor deposition (PECCVD, atomic layer deposition (ALD), and plasma enhanced atomic layer deposition (PEALD), and the vapor deposition is conducted at one or more temperatures ranging from about 25° C. to about 400° C. using an alkylsilane precursor selected from the group consisting of diethylsilane, triethylsilane, and combinations thereof.