Patent ID: 7507508

Claim:
A method for manufacturing semiconductor devices, comprising the steps of: accessing a plurality of exposure conditions of an exposure device having an optical axis: adjusting the exposure device in view of the assessed exposure conditions; and using the adjusted exposure device during processing of a semiconductor wafer to fabricate the semiconductor devices, wherein the step of adjusting the exposure device comprises a preliminary step (a) and a preliminary step (b), wherein said preliminary step (a) comprises the steps of: (i) forming a plurality of first assessment patterns and second assessment patterns on a principal surface of a first wafer-shaped workpiece with a plurality of exposure conditions in which the amount of exposure and the focal position are varied, said second assessment patterns being disposed lower than said first assessment patterns in the direction of the optical axis of said exposure device; (ii) measuring the dimensions of said first assessment patterns and said second assessment patterns; (iii) calculating a first difference and a first average between the measured dimensions of said first assessment patterns and the measured dimensions of said second assessment patterns that are formed with the same amount of exposure and the same focal position; and (iv) creating baseline data with respect to the exposure conditions based on said first difference and said first average; and wherein said preliminary step (b) comprises the steps of: (i) forming further first assessment patterns and further second assessment patterns on a principal surface of a second wafer-shaped workpiece with a predetermined amount of exposure and focal position; (ii) measuring the dimensions of said further first assessment patterns and the dimensions of said further second assessment patterns; (iii) calculating a second difference and a second average between the measured dimensions of said further first assessment patterns and the measured dimensions of said further second assessment patterns; and (iv) assessing said exposure conditions by substituting said second difference and said second average for said baseline data and then calculating the actual amount of exposure and the actual focal position that are to be set in the adjusting step.