A theoretical and experimental investigation of the developed profile shape in thick resist layers is described. The profiles that are exposed by a single line scan at various incident doses and by two adjacent scans with increasing separations between the scans are compared with a threshold solubility model and a development model. Near the neck of the profiles, the predictions of the theoretical models are in good agreement with experiments. In the resist substrate interface regions, the development model is satisfactory but the threshold solubility model is found to be inadequate. A proximity effect correction method is also described in which the edge of the exposed pattern is monitored to obtain accurate pattern fidelity. Experimental results using this method of correction are presented.