Abstract: Methods and apparatus for self-assembled monolayer (SAM) deposition are provided herein. In some embodiments, an apparatus for self-assembled monolayer (SAM) deposition includes: a chamber enclosing a processing volume; a substrate support disposed in the chamber and configured to support a substrate in the processing volume; a gas distribution system coupled to the chamber and configured to distribute a process gas into the processing volume; a first SAM precursor source fluidly coupled to the gas distribution system to provide a first SAM precursor as a part of the process gas; and a second SAM precursor source fluidly coupled to the gas distribution system to provide a second SAM precursor, different than the first SAM precursor, as a part of the process gas, wherein the first and second SAM precursor sources are independently controllable to control a relative percentage of the first and second SAM precursors in the process gas with respect to each other.