Projection exposure apparatus

A projection exposure apparatus, comprising:

• holding means for holding a substrate having a photosensitive layer;
• a projection lens system for projecting an image of a pattern of an original on the substrate with a sensitizing beam to record the pattern on the photosensitive layer;
• driving means for moving said holding means along an image plane of said projection lens system;
• measuring means for measuring the amount of movement of said holding means along the image plane;
• a first detection optical system for detecting a mark of the substrate and the pattern recorded on the photosensitive layer, through said projection lens system and with a first non-sensitizing beam;
• a second detection optical system for detecting the mark of the substrate and the pattern recorded on the photosensitive layer, without said projection lens system and with a second non-sensitizing beam having a bandwidth broader than that of the first non-sensitizing beam;
• and
• control means for controlling the position of said holding means by using said measuring means and said driving means to allow detection of the mark of the substrate and the pattern recorded on the photosensitive layer, through said first and second detection optical systems, wherein said control means produces first distance information representing the positional relationship between the mark of the substrate and the pattern recorded on the photosensitive layer, by using said first detection optical system, said control means produces second distance information representing the positional relationship between the mark of the substrate and the pattern recorded on the photosensitive layer, by using said second detection optical system, and said control means determines an error in the detection of the position of the mark of the substrate through said first detection optical system, on the basis of a difference between the first and second distance information.

In a semiconductor device manufacturing method usable with a first detection optical system for detecting through a projection lens the position of a mark of a wafer with a first non-sensitizing beam and a second detection optical system for detecting without the projection lens the position of the mark of the wafer with a second non-sensitizing beam having a bandwidth broader than that of the first non-sensitizing beam, wherein, after the wafer is brought into alignment with a mask on the basis of the detection of the mark of the wafer by using one of the first and second detection optical systems, a circuit pattern of the mask is projected onto the wafer through the projection lens, the improvement comprising the steps of:

• detecting a reference mark provided on means for holding the wafer, by using the first and second detection optical systems to produce first distance information related to the distance between first and second optical axes;
• detecting the mark of the wafer by using the first and second detection optical systems to produce second distance information related to the distance between the first and second optical axes;
• detecting the mark of the wafer by using the first detection optical system to produce information related to the position of the mark of the wafer;
• determining an offset on the basis of a difference between the first distance information and the second distance information;
• and
• correcting, with the offset, the information related to the position of the mark of the wafer to determine the position of the mark of the wafer.