Photoluminescence Imaging of Multicrystalline Si Wafers during HF Etching

Abstract

Rapid characterization of multicrystalline Si wafers was demonstrated by photoluminescence (PL) imaging with the wafers immersed in a HF solution. Highly spatially-resolved PL images were obtained within 1 s by the present technique. We found that the PL intensity from the HF-dipped wafers increased two orders of magnitude higher than that from wafers without the HF immersion. We examined the effects of the HF concentration on the surface property, and concluded that 5% HF etching was the most appropriate surface treatment. Temporal variations of PL intensity after the HF etching were also investigated. The intensity immediately decreased within 1 min after the etching, which indicated that no sooner had the wafer been taken from the HF solution than the surface defects dramatically increased. These findings showed clearly that PL imaging during HF etching is a powerful tool for characterizing the accurate bulk property.