As transistor dimensions shrinks, the requirement for wafer critical dimensions control is becoming increasingly
challenging. The intra-field critical dimension uniformity (CDU) of the features on the reticle is one of the many
sources of wafer CD variation. In this paper, we study how the CDU on the reticle can be obtained by using the
intensity information collected during reticle inspection (iCDUTM) on the KLA-Tencor TeraScan reticle inspection
tool. The collected CDU information of the reticle is then applied as an intra-field dose correction function to
improve wafer intra-field CD uniformity.
Using this method of extracting the reticle CDU from the intensity information allows for simple integration into a
high-volume production environment and an improved capability for intra-field CDU correction without the need to
expose any wafers for CD measurement nor any GDS design information. The ability to apply iCDU on prototype
devices on first pass run can also accelerate device development.