US Patent 9256133 Apparatus and method for developing process

An apparatus includes at least two tanks, at least two pumps, at least one nozzle, and a chuck. The apparatus provides multiple developers with different polarities during a developing process to target portions of a latent resist profile having different polarities, and thus different solubility. This apparatus also allows a mixture of two developers to be used for the resist film developing. A polarity of the mixture is adjustable by controlling a ratio of one pump flow rate to another pump flow rate and further controlling the resist pattern profile.