Makyoh topography (MT) is an optical method for the qualitative observation of the surface topography of mirror-like surfaces. The studied surface is illuminated by a collimated light beam, and an image is projected onto a distant screen, where an image is formed due to the focusing/defocusing action of the morphological features of the surface [3]. MT has been used in semiconductor technology from the 90’s, mainly for the assessment of the polishing quality of wafers.

Although swirl defects have also been observed by MT [4], a systematic study is still lacking. The aim of the present paper is just to perform such a systematic investigation. We compare two series of p-type wafers of varying dopant concentration from different vendors. We show the unambiguous correlation with the high dopant concentration, and point out the differences between the wafers of the two vendors. Other detects are also observed and the possible origins are discussed.

The results are interpreted using a geometrical optical model of MT imaging of sine surfaces which predicts the observed contrast as a function of surface feature amplitude and period [5]. The results are compared to surface stylus measurements, and the possibility and limitations of the extraction of quantitative data are discussed.

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