Etching composition and method for fabricating semiconductor device using the same

An etching composition comprising a silyl phosphate compound represented by the following formula 1, phosphoric add and deionized water:

• wherein R1 is selected from the group consisting of hydrogen, hydroxyl, substituted or unsubstituted (C1-C20)alkyl, (C1-C20)alkoxy, (C2-C20)alkenyl, (C3-C20)cycloalkyl, amino(C1-C20)alkyl, amino(C1-C10)alkylamino(C1-C10)alkyl, (C6-C20)aryl, (C1-C20)alkylcarbonyl, (C1-C20)alkylcarbonyloxy and cyano(C1-C10)alkyl;
• wherein R2 and R3 are each independently selected from the group consisting of hydrogen, hydroxyl, substituted or unsubstituted (C1-C20)alkyl, (C1-C20)alkoxy, (C2-C20)alkenyl, (C3-C20)cycloalkyl, amino(C1-C20)alkyl, amino(C1-C10) alkylamino(C1-C10)alkyl, (C6-C20)aryl, (C1-C20)alkylcarbonyl, (C1-C20)alkylcarbonyloxy, cyano(C1-C10)alkyl, and a group represented by the following formula 3:
• wherein R4 and R5 are each independently selected from the group consisting of hydrogen, (C1-C10)alkyl, (C2-C10)alkenyl, (C3-C20)cycloalkyl, amino(C1-C10)alkyl, and (C1-C10)alkyl substituted with one or more substituents selected from the group consisting of halogen, phenyl and cyclohexene oxide;
• and
• wherein n is an integer of 1≦n≦4.