Patent ID: 6562691
Filing Date: 2003-05-13
Classification: G03F,H01L,Y10S

Abstract:
A method for forming protrusive alignment-mark, comprising:providing a substrate; performing a photolithography process to form a patterned photoresist layer on said substrate wherein said substrate has an element region and an alignment region, and said patterned photoresist layer has an element photoresist-patterned region and an alignment photoresist-patterned region; depositing a first dielectric layer on the element photoresist-patterned region and said alignment photoresist-patterned region; removing the excess portion of said first dielectric layer above said patterned photoresist layer such that said patterned photoresist layer is coplanar with said first dielectric layer and thus said patterned photoresist layer is exposed; stripping said patterned photoresist layer on the element region and said alignment region to form a protrusive alignment-mark on said alignment region; forming a second dielectric layer on said protrusive alignment-mark and the element region for retaining a step height of said protrusive alignment-mark, wherein the thickness of said protrusive alignment-mark is determined by Dam&gE;(S+Dc), which S is said step height and Dc is the thickness of said first conductive layer; performing an etching process with respect to the element region and said alignment region to remove said second dielectric layer on said protrusive alignment-mark, and etching a contact hole on the element region; forming a first conductive layer on said protrusive alignment-mark and the element region; employing a planarization process to planarize the element region to retain said step height of said protrusive alignment-mark all the time; and forming a second conductive layer on said protrusive alignment-mark and the element region for multilevel interconnects.