Surfscan SP 2 TBI Particle Defect

The KLA Surfscan SP 2 TBI is a particle-defect system used for metrology and inspection. The model designation is Surfscan SP 2 TBI. KLA is the manufacturer.^[1][2]

A Surfscan-type inspection tool directs a laser beam across the wafer surface while the wafer is moved on a precision stage. Collectors positioned above and around the surface capture scattered light, because particles and surface defects scatter light differently from a smooth film or bare substrate. The optical signals are converted into a defect map that assigns coordinates and an apparent size to each event. The same light-scattering measurement can also yield surface haze information related to roughness.

Surfscan-type systems are used as in-line monitors at several points in wafer manufacturing. Such systems qualify incoming wafer surfaces, verify cleanliness after wet cleans, and check monitor wafers after process steps such as deposition, polish, or etch. Results are measured on production or monitor wafers, so they guide process-control decisions before wafers move to the next operation.

Surface scanners of this kind are used for particle contamination monitoring, defect density trending, and scratch or haze detection on wafer surfaces. Typical applications include clean-room and cleaning-bath qualification, process-tool monitoring, and incoming-quality inspection of bare wafers. The recorded defect locations and sizes help process engineers identify excursion sources and return the process to control.