Abstract: A resistivity map is prepared depicting the sheet resistance of a resistive film formed on a wafer as a function of position on the wafer. The resistivity map includes a plurality of zones each of which encompasses a specific range of resistivities of the resistive film. A mask containing numerous patterns which define associated resistors in the resistive film is divided into a plurality of zones which correspond to the plurality of zones of the resistivity map. One or more of the dimensions of the resistor patterns within each zone of the mask is automatically altered in a manner so as to compensate for the resistivity range of the corresponding zone of the resistivity map. Thus, in those portions of the resistive film where the sheet resistance is higher than the film's intended value, the width of the patterns in corresponding portions of the resistor mask are increased by an appropriate amount, thereby compensating for the higher sheet resistance.