Activated cleaning chemistries via megasonic energy for low-stress post-chemical mechanical planarization of SiC | Poster Board #1135

The manufacturing of Integrated Circuit (IC) technologies has been shifting focus to wide band gap (WBG) materials (i.e., Silicon carbide (SiC)) over the recent years. These WBG materials have shown promise as semiconductor materials due to the intrinsic properties (i.e., high capacitance, thermal stability, and wear resistance) of the material. As a result, the Chemical Mechanical Planarization (CMP) process utilizes aggressive chemical conditions and increasing shear forces to obtain the desired material removal rates (MRR). Unfortunately, this process often results in contamination/defectivity (i.e., organic residue, abrasive particles, etc.) left on post-polish SiC surfaces. This harsh CMP process leads to complexity within the post-CMP cleaning process to remove these contaminants/defects and make the substrates usable for device integration. Traditional post-CMP cleaning methods consist of a Polyvinyl alcohol (PVA) brush scrubbing on the surface, which has been shown to proliferate secondary defects (i.e., scratches, particle agglomerations, etc.). Therefore, alternative post-CMP cleaning methods utilize non-contact cleaning processes to reduce the formation of secondary defects associated with contact-based cleaning. One method of non-contact cleaning is the use of acoustic waves and cavitation generated via megasonic energy to target the removal of defects (i.e., organic residue, pad debris, particle agglomerations, etc.) and avoid secondary defect generation. This research focuses on developing a non-contact post-CMP cleaning process on SiC substrates. The coupling of megasonic energy and catalytic complexes for generating reactive oxygen species (ROS) will aid in removing organic residue and particles on the SiC surface. Furthermore, the generation of hydroxyl radical (*OH) and singlet oxygen (¹O₂) via organometallic complexes and other surface activating chemistry allows for more significant disruption of the defects non-covalently bonded to the SiC surface. Initial results of ROS-generating complexes have shown improvements in the overall cleaning efficiency via a decrease in the variability of particle removal and a reduction in the residue left behind from the cleaning chemistry.