摘要 |
A technique for the determination of dynamic lens field curvature uniquely associated with a photolithographic scanner is described. A series of lithographic exposures is performed on a resist coated silicon wafer using a photolithographic scanner. The lithographic exposures produce an array of focusing fiducials that are displaced relative to each other in a unique way. The resulting measurements are fed into a computer algorithm that determines the dynamic lens field curvature (ZDLC) perpendicular to the scanning direction in an absolute sense. Furthermore, the effects of wafer flatness, wafer surface non-uniformity, and stage error are considered. The ZDLC information can be used to improve lithographic modeling, overlay modeling, and advanced process control techniques related to scanner stage dynamics.
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申请人 |
LITEL INSTRUMENTS;SMITH, ADLAI, H.;HUNTER, ROBERT, O., JR. |
发明人 |
SMITH, ADLAI, H.;HUNTER, ROBERT, O., JR. |