An etchant composition includes a silane compound represented by the following Chemical Formula 1: wherein R1 to R6 are independently hydrogen, halogen, a substituted or unsubstituted C1-C20 hydrocarbyl group, a phenyl group, a C1-C20 alkoxy group, a carboxy group, a carbonyl group, a nitro group, a tri(C1-C20) alkylsilyl group, a phosphoryl group, or a cyano group, L is a direct bond or C1-C3 hydrocarbylene, A is an n-valent radical, and n is an integer of 1 to 4.