Patent ID: 6544694
Filing Date: 2003-04-08
Classification: G03F

Abstract:
A method of manufacturing a device in at least one layer on a substrate, comprising the steps of:imaging, by means of projection radiation having a wavelength &lgr; and a projection system having a numerical aperture NA, a specific phase shifting mask pattern, comprising pattern features corresponding to device features to be configured in said layer, on a radiation-sensitive layer provided on said layer, and removing material from, or adding material to, areas of said layer which are delineated by the mask pattern image, the smallest device features having a width which is smaller than &lgr;/NA, characterized in that use is made of a mask pattern comprising mask features which are constituted by the combination of a phase transition determining the position of the imaged mask feature in the device layer and the length of the imaged mask feature, and two sub-resolution assist features flanking the phase transition and having a specific mutual distance which substantially determines the width of the imaged mask feature in the device layer, and wherein imaged mask features having substantially different widths can be produced in the device layer by varying the mutual distance of the respective assist features on the mask pattern.