The present disclosure relates to a chemical vapor deposition apparatus and associated methods. In some embodiments, the CVD apparatus has a vacuum chamber and a gas import having a gas import axis through which a process gas is imported into the vacuum chamber and being arranged near an upper region of the vacuum chamber. At least one exhaust port is arranged near a bottom region of the vacuum chamber. The CVD apparatus also has a shower head arranged under the gas import having a plurality of holes formed there through. The shower head redistributes the process gas to form a precursor material with an uneven thickness that matches a remove profile of a subsequent CMP process. As a result, planarity of the formed layer after the CMP process is improved.