Inline Metrology ConfoVis WaferINSPECT AOI 305

Automatisierte Vermessung der Federbreiten über den gesamten Wafer mit anschließender Ausgabe einer farblich dargestellten Wafermap.
© Fraunhofer ENAS
Automated measurement of the spring widths over the entire wafer with subsequent output of a color-coded wafer map.
Overlay Bestimmung mittels offener Box-in-Box Strukturen. Um den Overlay weiter zu minimieren kann anschließend eine Kompensation ausgeführt werden.
© Fraunhofer ENAS
Overlay determination by means of open box-in-box structures. To further minimize the overlay, a compensation can be performed afterwards.
Wafermap für vorhandene Defekte - Defekterkennung mittels Golden-Sample-Methode.
© Fraunhofer ENAS
Wafer map for existing defects - defect detection using golden sample method.

Automated optical measurements for statistical evaluation are possible with the Confovis AOI WaferINSPECT 305, a confocal measuring system equipped with objectives ranging from 2.5x to 100x magnification. Single wafers in sizes 4", 6", and 8" can be loaded onto the automatic vacuum stage. In manual mode, individual chips can also be characterized. The system captures up to 20 optical planes per second, performing a contrast evaluation to automatically determine the focus point. Wafer layout/geometry can be learned to perform automated measurement tasks, enabling both 2D and 3D measurements. The measurement results can be output as a wafer map during automated measurements, allowing quick capture and analysis of changes across the entire wafer. Examples include focus/dose variations or the investigation of inhomogeneities in etching processes. The height resolution is up to 3 nm according to VDI 2655, and laterally a resolution of up to 267 nm according to Rayleigh can be achieved. The Cognex software operating in the background enables, through AI-supported image recognition, not only the automatic measurement of geometric structures but also defect detection using the Golden Sample method. Overlay measurements for controlling successive lithography layers represent another application.

 

Highlights:

  • Automated confocal measuring system
  • 2D and 3D imaging and statistical evaluations across the entire wafer
  • Overlay evaluations for quality control of successive lithography layers
  • AI-supported image recognition via Cognex software
  • Defect detection using the Golden Sample method