For the surface of a semiconductor chip (wafer) to be measured or analyzed, 3D-data has to be collected of sufficient resolution to allow the examination of structures or geometries of the circuits on its surface. Today’s chip technologies require nanoscale resolution in the axial direction and a few micrometers in lateral direction. It goes without saying that the fragile parts should not be touched during the measurement and so the only option is to measure in a noncontact mode. More often than not semiconductor profiling comes down to the need to deliver high density 3D data from a large surface area that contains the finest structures.
With Precitec Optronik´s new range of chromatic confocal line sensors 192 measuring points simultaneously profile the surface in 5.2x10-3 (1/200) of the time needed compared to conventional sensors, which use only one measuring point. The current generation of line sensors from Precitec Optronik operates with 192 measuring points, which measure, depending on the probe, in a line from 1 mm up to 5 mm in length.
3D-Data within the shortest time
The raw data delivered by the sensor can be processed in software to detect periodic patterns and structures. Most frequently used are coded height views to detect faults by observing the height, radii, diameters and gaps in structures. Precitec´s systems are working at an enhanced frequency of over one million points per second. Those line sensors are currently the fastest way of acquiring three dimensional semiconductor topographies.
Link: Video
(Contactless 3D topography measurement of wafers using a CHRocodile CLS line sensor)