Method for aligning substrate and mask and method for preparing semiconductor device

Abstract

The invention relates to the technical field of an alignment method, and discloses a method for aligning substrate and mask, including: firstly forming at least one set of alignment marks on a mask plate; selecting a certain number of large-size substrates as sample substrates; forming a plurality of sets of alignment marks on each sample substrate using the mask plate and the at least one set of alignment marks formed thereon to divide the sample substrate into a plurality of sub-substrate areas; and then performing mask process on the respective sample substrates, accurate alignment for each sub-substrate area can be realized by means of the plurality of sets of alignment marks on the sample substrate, and one sub-substrate area can be accurately aligned by means of at least two sets of alignment marks formed on the sample substrate. In the alignment, positions of the plurality of sets of alignment marks formed on the sample substrate are recorded and stored, and mask process on a non-sample substrate is performed based on parameters relating to the stored positions of the plurality of sets of alignment marks, thus the seaming degree between patterns in the same layer and the coincidence degree between patterns in different layers on the non-sample substrate are guaranteed, so that mass production for large-size substrates with good quality can be realized. The invention also discloses a method for preparing semiconductor device.