A method of semiconductor fabrication is provided. The method includes providing a model for a device parameter of a wafer as a function of first and second process parameters. The first and second process parameters correspond to different wafer characteristics, respectively. The method includes deriving target values of the first and second process parameters based on a specified target value of the device parameter. The method includes performing a first fabrication process in response to the target value of the first process parameter. The method includes measuring an actual value of the first process parameter thereafter. The method includes updating the model using the actual value of the first process parameter. The method includes deriving a revised target value of the second process parameter using the updated model. The method includes performing a second fabrication process in response to the revised target value of the second process parameter.