Patent ID: 7220521

Claim:
A method of fabricating a semiconductor device that includes an exposing process in which a lower pattern is formed by a first exposing process and an upper pattern is formed thereon by a second exposing process, said exposing process comprising: an earlier exposure step of aligning and exposing, in a just-before lot conducted immediately before a current lot, an upper pattern on a substrate of said just-before lot, on which a lower pattern is formed by said first exposing process, by conducting said second exposing process such that said upper pattern is in alignment with said lower pattern; and a latter exposure step of aligning and exposing, in said current lot, an upper pattern on a substrate of said current lot, on which a lower pattern is formed by said first exposing process, by conducting said second exposing process such that said upper pattern is in alignment with said lower pattern on said substrate of said current lot, said exposure process further comprising the steps of: obtaining a first correction value representing a difference of first and second alignment error correction parameter preset values respectively used at the time of said first exposing process of exposing said lower patterns in said current lot and in said just-before lot; obtaining, as a second correction value, an optimum correction amount of a third alignment error correction parameter preset value, which has been needed for proper alignment of said upper pattern in said second exposing process of said just-before lot, said third alignment error correction parameter has been used in said second exposing process of said just-before lot for exposing said upper pattern; obtaining an optimum correction parameter prediction value to be used for exposing said upper pattern in said second exposing process of said current lot, from said first correction value and said second correction value; and exposing said upper pattern of said current lot in said latter exposure step while using said optimum parameter prediction value.