Abstract: Corner rounding and image shortening is substantially reduced in an image printed on a substrate by illuminating a photolithographic mask and projecting light transmitted through the photolithographic mask onto the substrate using an optical projection system. The photolithographic mask has a mask pattern that includes at least one printable feature having at least one corner. Incorporated, in the mask pattern, is at least one line feature corresponding to the corner of the printable feature. The line feature is in at least close proximity to the corresponding corner of the printable feature and has a line width that is smaller than a minimum resolution of the optical projection system.

Abstract: A wafer having a top surface including a first material such as silicon dioxide or silicon nitride and a second material such as polysilicon or copper is etched so as to leave elements formed from the second material projecting above the surrounding surface defined by the first material. An opaque layer may be applied over the newly-formed top surface covered by a transparent layer such as a photoresist. The opaque layer has raised features corresponding to the projecting features formed from the second material. These raised features provide contrast and allow an optical system to locate the wafer as, for example, in registering the wafer in a wafer stepper. Alternatively, transparent layers such as an oxide dielectric and a photoresist may be applied after etching. The projecting elements formed by etching remain visible through the transparent layers and similarly allow optical location.

Abstract: Corner rounding and image shortening is substantially reduced in an image printed on a substrate by illuminating a photolithographic mask and projecting light transmitted through the photolithographic mask onto the substrate using an optical projection system. The photolithographic mask has a mask pattern that includes at least one printable feature having at least one corner. Incorporated, in the mask pattern, is at least one line feature corresponding to the corner of the printable feature. The line feature is in at least close proximity to the corresponding corner of the printable feature and has a line width that is smaller than a minimum resolution of the optical projection system.