A method for forming a protrusive alignment-mark in semiconductor devices is disclosed. A photolithography process is performed to form a photoresist layer on a substrate wherein the substrate has an element region and an alignment region, and the photoresist layer has an element photoresist region and an alignment photoresist region. Afterwards, a first dielectric layer is deposited on the element photoresist region and the alignment photoresist region. The excess portion of first dielectric layer above the photoresist layer is removed such that the photoresist layer is coplanar with the first dielectric layer and thus the photoresist layer is exposed. The photoresist layer on the element region and said alignment region is stripped to form a protrusive alignment-mark on the alignment region.