Focusing and tilting adjustment system for lithography aligner, manufacturing apparatus or inspection apparatus

A projection exposure apparatus comprising:

• (a) an imaging system for projecting an image of a mask pattern onto a substrate at a projection field;
• (b) a movable stage mechanism for moving in intersecting X and Y directions to position the substrate with respect to the image of the projected mask pattern;
• (c) an adjusting mechanism for adjusting a focus of the projected mask pattern image on the substrate;
• d) a first detection system having a detection area at a first position located outside the projection field of said imaging system and spaced apart from the projection field in the Y direction, said first detection system detecting the position of a principal surface of the substrate in a Z direction;
• (e) a second detection system having a detection area at a second position located outside the projection field of said imaging system and spaced apart from said first position in the X direction, said second detection system detecting the position of the principal surface of the substrate in the Z direction;
• (f) a third detection system having a detection area at a third position located outside the projection field of said imaging system, spaced apart from the projection field in the X direction and also spaced apart from said second position in the Y direction, said third detection system detecting the position of the principal surface of the substrate in the Z direction;
• (g) a calculator coupled to said first and second detection systems, and calculating a deviation between the first Z-position detected by said first detection system and a target Z-position and for storing the second Z-position detected by said second detection system at the time of detection made by said first detection system;
• and
• (h) a controller coupled to said adjusting system and said calculator and said third detection system, and controlling said adjusting mechanism on the basis of the calculated deviation, the stored second Z-position and the third Z-position detected by said third detection system when the area on the substrate corresponding to the detection area of said first detection system is positioned in the projection field of said imaging system by said movable stage mechanism.

A scanning exposure method in which a pattern of a mask is transferred onto a sensitive substrate by projecting a part of the mask pattern on the sensitive substrate through a projection system and by moving the mask and the sensitive substrate relative to a projection field of the projection system, the method comprising the steps of:

• (a) mounting the sensitive substrate on a holder having an auxiliary plate portion surrounding the sensitive substrate at a height substantially equal to a height of a principal surface of the sensitive substrate;
• (b) reading a focus error of an exposure area of the sensitive substrate on which area a part of the mask pattern is to be projected, the focus error of the exposure area being read before the exposure area reaches the projection field of the projection system during scanning movement of the holder and the sensitive substrate;
• (c) detecting a focus error of the principal surface of a part of one of the sensitive substrate and the auxiliary plate portion by an exposure position focus detection system disposed apart from the projection field of the projection system in a direction perpendicular to the direction of said scanning movement when the exposure area on the sensitive substrate reaches the projection field;
• and
• (d) adjusting the focus between the projection system and the sensitive substrate on the basis of the focus errors detected by said steps (b) and (c) so that the focus error of the exposure area on the sensitive substrate is corrected in the projection field of the projection system.

A focusing apparatus provided in an apparatus having an objective optical system to control focusing between a surface of a workpiece and the objective optical system, said focusing apparatus comprising:

• (a) a first detection system having a detection area at a first position located outside a field of said objective optical system, said first detection system detecting a position of the surface of the workpiece in the focusing direction;
• (b) a second detection system having a detection area at a second position located outside the field of said objective optical system and spaced apart from said first position, said second detection system detecting the position of the surface of the workpiece in the focusing direction;
• (c) a third detection system having a detection area at a third position located outside the field of said objective optical system and spaced apart from each of said first and second positions, said third detection system detecting the position of the surface of the workpiece in the focusing direction;
• (d) a calculator coupled to said first and second detection systems, and calculating a deviation between the first focus position detected by said first detection system and a target focus position and for storing the second focus position detected by said second detection system at the time of detection made by said first detection system;
• and
• (e) a controller coupled to said calculator and to said third detection system, and controlling focusing of the objective optical system on the surface of the workpiece on the basis of the calculated deviation, the stored second focus position and the third focus position detected by said third detection system when the area on the workpiece corresponding to the detection area of said first detection system is positioned in the field of said objective optical system by relative movement of the workpiece and the objective optical system.

A method of controlling focusing of an objective optical system onto a surface of a workpiece when the workpiece and a field of the objective optical system are moved relative to each other in X and Y directions, said method comprising the steps of:

• (a) mounting the workpiece on a holder having an auxiliary plate portion surrounding the workpiece at a height substantially equal to a height of the surface of the workpiece;
• (b) reading a focus error of a predetermined local portion of the surface of the workpiece before the local portion of the workpiece reaches the field of the objective optical system during movement of said holder and the workpiece in a predetermined moving direction;
• (c) detecting a focus error of the surface of a part of one of the workpiece and the auxiliary plate portion by a first focus detection system disposed apart from the field of the objective optical system in a direction perpendicular to the moving direction when the local portion of the workpiece reaches the field;
• and
• (d) controlling the focusing between the objective optical system and the workpiece on the basis of the focus errors detected by said steps (b) and (c) so that the focus error of the local portion of the workpiece is corrected in the field of the objective optical system.