Enhanced reflectivity coating (erc) for narrow aperture width contact

Abstract

A method for forming for use within an integrated circuit a narrow aperture width patterned positive photoresist layer from a blanket positive photoresist layer. There is first formed over a semiconductor substrate a reflective layer. There is then formed upon the reflective layer a blanket positive photoresist layer. There is then photoexposed through a reticle the blanket positive photoresist layer to form a photoexposed blanket positive photoresist layer. Finally, the photoexposed blanket positive photoresist layer is developed to form a narrow aperture width patterned positive photoresist layer. The narrow aperture width patterned positive photoresist layer may then be employed as a narrow aperture width patterned positive photoresist etch mask layer in patterning a narrow aperture width patterned reflective layer from the reflective layer. In addition, at least the narrow aperture width patterned reflective layer may then be employed in forming an aperture at least partially through a substrate layer formed beneath the reflective layer. Typically, the aperture will be a contact or interconnection via completely through an insulator layer formed beneath the reflective layer. The method reduces the photoexposure energy and compensates for depth of focus limitations in forming the narrow aperture width patterned positive photoresist layer from the blanket positive photoresist layer.