A process of forming ultra fine patterns using bottom anti-reflective coating containing acid generator. More particularly, a process of forming vertical patterns using an organic bottom anti-reflective coating containing excessive amount of acid generator, in order to prevent formation of sloping patterns due to photoresist resins absorbing wavelength of light used as light sources during lithography process using light sources such as KrF, ArF, VUV, EUV, E-beam and ion beam, even when photoresist resins having high absorbance to light source are used.