Highly conformal magnesium oxide thin films by low-temperature chemical vapor deposition from Mg(H3BNMe2BH3) 2 and water

Pure, dense, and stoichiometric MgO thin films have been deposited at temperatures as low as 225 °C by chemical vapor deposition using a recently reported magnesium precursor, magnesium N,N-dimethylaminodiboranate, which has the highest room-temperature vapor pressure among known Mg-containing compounds, with water as a co-reactant. The films are characterized by x-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, and spectroscopic ellipsometry. Conformal coating on a trench with 35:1 aspect ratio is achieved at a film growth rate of 2 nm/min. The growth rate can be tuned between 2–20 nm/min according to the requirement of the structure to be coated.