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SemDex A32

SemDex A32

Production inspection in a clean room

Roughness in sub-nm range

Roughness is a term used to describe the non-flatness or 3D micro-topography of a wafer. After back grinding or etching the respective process can be characterised in terms of the roughness value. Thanks to the extremely high resolution of the StraDex a sensor integrated into the SemDex wafer-inspection system, roughnesses can be determined down to the sub-nm region. 

Roughness in sub-nm range

A comparative study has been performed for the first time with AFM (“Atomic Force Microscopy”) to establish the absolute accuracy of the method. The typical roughness parameters Ra/Rq/Rz can be read off directly (see, e.g., DIN EN ISO 4287 and ASME B46.1). The formerly used roughnesses of a 1D profile are being increasingly replaced by 2D measurements, which are significantly more robust.

Measuring systems for:

Roughness