(Invited) Innovations in “Low-Stress” Defect-Free Chemical Mechanical Planarization (CMP) Processes for Next Generation Wide Band Gap Semiconductors
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2025-07-11 |
| Journal | ECS Meeting Abstracts |
| Authors | Jason J. Keleher, Elizabeth Maeve McDonnell |
Abstract
Section titled “Abstract”Wide Band Gap (WBG) materials such as silicon carbide (SiC), gallium nitride (GaN), and diamond are emerging as novel substrates for the semiconductor industry due to their exceptional thermal stability, high capacitance, and superior wear resistance. These properties make WBG materials indispensable for next-generation devices and advanced electronics. However, the manufacturing of WBG materials poses significant challenges, particularly in achieving atomically smooth, defect-free surfaces necessary for device integration. Defects introduced during crystal growth and wafer slicing, such as scratches, pits, and residual contamination, require precise planarization and cleaning to enable reliable device performance. Chemical Mechanical Planarization (CMP) is critical for achieving the required surface flatness of WBG substrates but often introduces primary defects (e.g., organic residues, abrasive particles) and surface contamination. Conventional post-CMP cleaning methods rely on high-shear force Polyvinyl Alcohol (PVA) brush scrubbing, which frequently generates secondary defects, such as scratches and particle agglomerations. Therefore, innovative approaches are essential to minimize defectivity and ensure surface cleanliness without compromising substrate integrity. This research explores three case studies detailing innovative techniques in both polishing and cleaning WBG materials. First, organometallic complexes (OMCs) are investigated for enhancing CMP formulations, utilizing their redox activity to generate reactive oxygen species (ROS) that facilitate controlled oxidation and effective material removal. Second, megasonic energy is applied to develop a low-stress cleaning method. This technique leverages acoustic cavitation to activate cleaning chemistries and enhance the removal of particles and residues, thereby reducing the reliance on high-friction mechanical scrubbing. Lastly, supramolecular chemistries are employed to optimize cleaning efficacy by targeting particle encapsulation and adsorption dynamics, ensuring comprehensive defect removal. By integrating OMC-enhanced CMP, megasonic-assisted cleaning, and advanced structurally engineered supramolecular surfactants, this set of work aims to address the critical challenges associated with the planarization and cleaning of WBG substrates.