Improved chemical vapor deposition method of producing fluorine-doped tin oxide coatings

Claim 1

An improved chemical vapor deposition method of producing a fluorine-doped tin oxide coating which has a minimum and constant sheet resistance under different process conditions, comprising: (a) forming a liquid coating composition which includes an organic fluorine dopant and an organotin compound, said composition comprising: (1) 1-30 wt./ of an organic fluorine dopant wherein at least one fluorine atom is located alpha or beta to a functional group wherein carbon is bonded to oxygen selected from carboxylic acid, anhydride, ester, alcohol, ketone, acid halide, or ether; and (2) 70-99 wt./ of an organotin compound, which is an alkyltin trichloride, a dialkyltin dichloride, an alkyldichlorotin acetate, a dialkylchlorotin diacetate, or an ester tin trichloride; or tin tetrachloride; (b) vaporizing said liquid coating composition into a wet carrier gas to form a vapor mixture of carrier gas, water, organic fluorine dopant and organotin compound; and (c) decomposing said vapor mixture on a substrate to form said coating, characterized in that: the vapor concentrations of said components are such that a parameter M, defined as: where (AIR) is the concentration of the carrier gas, in moles, (H20) is the concentration of water in the carrier gas, in moles, (OFD) is the concentration of organic fluorine dopant in the carrier gas, in moles, and (0) is the concentration of organotin compound in the carrier gas, in moles, has a value of less than 50,000, thereby to produce a fluorine-doped tin oxide coating having a minimum and constant sheet resistance for said values of M.