Precursors and related methods are provided. A precursor comprises a cyclosilazane compound. The cyclosilazane compound is a reaction product of an aminosilane and a halosilane. A method for forming the precursor comprises obtaining an aminosilane, obtaining a halosilane, and contacting the aminosilane and the halosilane to obtain the precursor. A method for forming a silicon-containing film using the precursor is also provided, among other embodiments.