Abstract: The present invention relates to a growth inhibitor for forming a pellicle-protective thin film, a method of forming a pellicle-protective thin film using the growth inhibitor, and a mask fabricated by the method. More particularly, the growth inhibitor for forming a pellicle-protective thin film according to the present invention is a compound presented by Chemical Formula 1: AnBmXoYiZj. A is carbon or silicon; B is hydrogen or an alkyl group having 1 to 3 carbon atoms; X includes one or more of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I); Y and Z independently include one or more selected from the group consisting of oxygen, nitrogen, sulfur, and fluorine and are different from each other; n is an integer from 1 to 15; o is an integer greater than or equal to 1; m is 0 to 2n+1; and i and j are integers from 0 to 3.