Patent ID: 7652749

Claim:
A lithographic apparatus comprising: (a) a projection system configured to project a patterned radiation beam onto a substrate; and (b) a control system configured to control said apparatus according to a first software-functionality and a second software-functionality, the second software-functionality being a later activation than the first software-functionality, the control system comprising (i) a first database configured to contain an activation date/time of said second software-functionality; (ii) a second database configured to contain a first exposure date/time of said substrate; and (iii) a comparator to compare the activation date/time and the first exposure date/time, wherein if the first exposure date/time is later than the activation date/time, the control system is configured to use said second software-functionality, and if the first exposure date/time is earlier than the activation date/time, the control system is configured to use said first software-functionality.