Chemical Mechanical Planalization (CMP) is an established semiconductor process step in the integrated production of logic and memory devices. DI water is a critical component in these processes. There is a critical need to eliminate particle and metal ion contamination during post CMP cleaning while attempting to reduce DI water usage levels. There are a number of issues that a process engineer needs to consider when implementing a post CMP cleaning processes. These issues can include copper oxide film thickness before and after post CMP cleaning in, removal of BTAH inhibitor residues and the challenges for cleaning hydrophobic low-k films. The BCS (Buffered Chelating Solutions) solutions are effective for post CMP cleaning while being environmentally safe containing no fluorides or ammonia species. The chemistries are also compatible with the common brushes used with the current scrubbers and are compatible with most typical metal and oxide films used in the semiconductor industry. This paper will discuss some of the issues that need to be understood for post CMP cleaning. Results will be discussed for BCS solution chemistries (pH 7.5). Much of these results will focus on removing metal ions, copper oxides, BTAH films and particles with double-sided brush cleaning equipment while attempting to meet other post CMP cleaning requirements.
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