Method of Transferring a Substrate, Transfer System and Lithographic Projection Apparatus

A method of transferring a substrate from a first substrate holder to a second substrate holder in a lithographic projection apparatus using a transfer unit based on transfer data available thereto, said second substrate holder having a surface provided with a first plurality of burls, the method comprising:

• providing a memory encoded with burl position data related to the position of said first plurality of burls on the surface of said second substrate holder and substrate position data related to a position and orientation of said substrate with respect to a second plurality of burls provided on a surface of a third substrate holder used in an earlier process step performed on said substrate;
• providing said substrate on said first substrate holder;
• measuring a position error and an orientation of said substrate provided on said first substrate holder;
• calculating orientation adjustment data based on said burl position data, said substrate position data and said orientation as measured;
• adjusting the orientation of said substrate in accordance with said orientation adjustment data as calculated;
• and
• transferring said substrate using said transfer unit from the first substrate holder to the second substrate holder in accordance with said transfer data and placing said substrate on said second substrate holder.

A computer readable medium having computer executable code stored thereon, which, when loaded on a computer assembly, enables the computer assembly to control a method of transferring a substrate from a first substrate holder to a second substrate holder in a lithographic projection apparatus using a transfer unit based on transfer data available thereto, said second substrate holder having a surface provided with a first plurality of burls, the method comprising:

• providing a memory encoded with burl position data related to the position of said first plurality of burls on the surface of said second substrate holder and substrate position data related to a position and orientation of said substrate with respect to a second plurality of burls provided on a surface of a third substrate holder used in an earlier process step performed on said substrate;
• providing said substrate on said first substrate holder;
• measuring a position error and an orientation of said substrate provided on said first substrate holder;
• calculating orientation adjustment data based on said burl position data, said substrate position data and said orientation as measured;
• adjusting the orientation of said substrate in accordance with said orientation adjustment data as calculated;
• and
• transferring said substrate using said transfer unit from the first substrate holder to the second substrate holder in accordance with said transfer data and placing said substrate on said second substrate holder.

A transfer system for transferring a substrate based on transfer data available thereto, the transfer system comprising:

• a first substrate holder provided with a surface configured to hold said substrate;
• a sensor configured to determine a position error and an orientation of said substrate when provided on said first substrate holder;
• a second substrate holder comprising a surface provided with a first plurality of burls, said surface being configured to hold said substrate;
• a memory encoded with burl position data related to the position of said first plurality of burls on the surface of said second substrate holder and substrate position data related to a position and orientation of said substrate with respect to a second plurality of burls provided on a surface of a third substrate holder used in an earlier process step performed on said substrate;
• a processor communicated to said sensor, and said memory, the processor being configured to calculate orientation adjustment data on the basis of said burl position data, said substrate position data and said orientation as determined;
• an orientation adjustment unit configured to adjust the orientation of said substrate on said first substrate holder in accordance with the orientation adjustment data as calculated with said processor;
• and
• a transfer unit configured to transfer said substrate from said first substrate holder to said second substrate holder in accordance with the transfer data.