Method for integrated circuit fabrication

摘要

Provided is an integrated circuit (IC) fabrication method. The method includes receiving a mask, the mask having a plurality of dies and receiving a wafer, the wafer having a resist layer. The method further includes exposing the resist layer using the mask with a fraction radiation dose thereby forming a first plurality of images; re-positioning the mask relative to the wafer; and exposing the resist layer using the mask with another fraction radiation dose. A second plurality of images is formed, wherein a portion of the second plurality of images is superimposed over another portion of the first plurality of images.

主权项

1. A method comprising:
receiving a mask and a wafer, wherein the mask includes a plurality of units and each of the units corresponds to a first pattern of an IC and the wafer includes a first substrate and a first resist layer over the first substrate; performing a first exposure to the first resist layer using the mask thereby forming a first plurality of images on the first resist layer, wherein the first exposure uses a first radiation dose that is less than a full radiation dose and each of the first plurality of images corresponds to one of the units; and performing a second exposure to the first resist layer using the mask thereby forming a second plurality of images on the first resist layer, wherein the second exposure uses a second radiation dose that is less than the full radiation dose; each of the second plurality of images corresponds to one of the units; and a second portion of the second plurality of images is superimposed over a first portion of the first plurality of images, wherein the first radiation dose and the second radiation dose are at least 1/N of the full radiation dose each, wherein N is the number of the units.