Low undercut Ti Etch chemistry for Cu bump pillar under bump metallization Wet Etch process

This paper demonstrates how a low undercut Ti etchant developed by Technic France can be successfully introduced in a high volume manufacturing Fab for etching the under bump metallization (UBM). The Ti etchant has been tested on 300mm wafer production equipment in GLOBALFOUNDRIES. The Ti etchant evaluation has been carried out in collaboration with the Fraunhofer IZM-ASSID institute.