Course-based undergraduate research experiences (CUREs) are becoming more prevalent throughout chemistry curricula as a mechanism to lower barriers to participation, improve retention, and decrease success gaps for historically minoritized populations. Given the evidence that longduration and early entry experiences are more impactful, herein we describe a semester-long CURE in General Chemistry II Lab. The curriculum outcomes were assessed with an inquiry classification scheme and a rubric blended from Auchincloss et al. and Clark et al. Student outcomes were assessed in the context of the five essential components of authentic research experiences utilizing Lopatto's CURE Survey, student lab reports, and interviews from graduate assistants and peer research mentors. A comparison to benchmark data and those reported for upper-division chemistry CUREs reveals significant gains in scientific skills, communication, and attitudes about science.

The Chemical Mechanical Planarization (CMP) process can cause various defects, and they can be classified as mechanical (i.e., scratching), chemical (i.e., corrosion), or physiochemical (i.e., adsorbed contaminants) according to the mechanism of formation. Traditionally, a contact cleaning method involving a poly-vinyl alcohol (PVA) brush is used to transfer cleaning chemistry to the substrate of interest as well as provide the necessary mechanical energy for defect removal. While this process is effective in contaminant removal its reliance on shear forces can induce secondary defect modes, such as scratching. To minimize the aforementioned induced defectivity during contact p-CMP processes, the implementation of non-contact modalities has become of the utmost importance. This work will focus on the rationale design of p-CMP cleaning systems for emerging materials such as SiC, carbon-doped oxides, and metals. “Soft” cleaning chemistry structure (i.e., shape and charge), and processes play a critical role in cleaning efficacy under low stress conditions.

Wide band gap (WBG) materials (i.e., Silicon Carbide (SiC)) have attracted much attention in the semiconductor arena because of their intrinsic properties (i.e. high capacitance, thermal stability, and wear resistance). In order to achieve the desired removal rate and surface planarity during the Chemical Mechanical Planarization (CMP) process of SiC substrates high shear force and chemically aggressive conditions are employed. Although effective this process can result in significant surface contamination/defectivity (i.e., organic residue, abrasive particles, etc.) post-polish. Current methods of post-CMP cleaning for SiC substrates implement a Polyvinyl Alcohol (PVA) brush scrubbing to aid in surface contaminate removal. A balance of controlled shear force and interfacial adsorption/redox reactions are necessary to effectively remove rouge contaminates without any generation of secondary defects. This research focuses on development of a “soft” (low-shear force) post-CMP cleaning process for SiC which uses transient cavitation effects via megasonic energy coupled with catalytic complexes to enhance reactive oxygen species (ROS) generation. More specifically, hydroxyl radical (*OH) generating organometallic complexes were incorporated into the cleaning fluid to increase ROS and provide additional surface-active chemistries to disrupt the defects non-covalent surface binding energy. Initial results show increased ROS generation (which is complex structure dependent) improved defect removal efficiency under static megasonic conditions with no changes to the surface energy of the final polished SiC substrate.

As integrated circuit and logic device feature sizes approach the 3-nm node, limiting induced defectivity during Chemical Mechanical Planarization (CMP) process (polishing and substrate cleaning) is of utmost importance. The CMP process can cause various defects, and they can be classified as mechanical (i.e., scratching), chemical (i.e., corrosion), or physiochemical (i.e., adsorbed contaminants) according to the mechanism of formation. Traditionally, a contact cleaning method involving a poly-vinyl alcohol (PVA) brush is used to transfer cleaning chemistry to the substrate of interest as well as provide the necessary mechanical energy for defect removal. While this process is effective in contaminant removal its reliance on shear forces can induce secondary defect modes, such as scratching. To minimize the aforementioned induced defectivity during contact p-CMP processes, the implementation of non-contact modalities has become of the utmost importance. This work will focus on the rationale design of p-CMP cleaning systems for emerging materials such as SiC, GaN, carbon-doped oxides, and metals. More specifically, “OVER”-cutting and “soft” cleaning processes that balance the modulation of surface reaction kinetics (chemical and adsorption) with advanced low shear force environment will be evaluated. For example, employing supramolecular cleaning chemistries coupled with reactive oxygen species (ROS) generating complexes under megasonic action were evaluated for effective SiC cleaning. Results from a second order kinetic model indicate that processing conditions (i.e., time and power), “soft” cleaning chemistry structure (i.e., shape and charge), and the generation of ROS all play a critical role in cleaning efficacy under low stress conditions in the megasonic field. Utilizing a suite of dynamic analytical techniques (i.e., atomic force microscopy, quartz crystal microbalance, contact angle, zeta potential, and electrochemical analysis, shear force analysis) a correlation between interfacial reaction mechanisms and effective p-CMP cleaning will be presented.

Wide band gap (WBG) materials (i.e. Silicon Carbide (SiC)) are rapidly emerging in the semiconductor arena because of their properties (i.e. high capacitance, thermal stability, and wear resistance), which allow these substrates to be used as insulating wafers and transistors in integrated circuits (IC). During CMP, removable defects (i.e. particles, organic residues, pad debris etc.) and non-removable defects (i.e. scratches or corrosion) are generated on the wafer surface. Industry standards currently utilize aggressive post-CMP processing conditions, which may lead to further defectivity. This research focuses on a comparison between an industry-standard brush cleaning (i.e. contact mode) and an emerging megasonic cleaning approach (i.e non-contact mode). Implementation of supramolecular cleaning chemistries such as micelles, vesicles, and polyelectrolytes will be employed in both modes as an alternative “soft” cleaning process. Initial results indicate a correlation between the structure of the “soft” cleaning additives on overall simulated defect removal. In addition, significant concentration dependency (i.e. above and below the critical micelle concentration (CMC)) emerged as a key driver for the rate of defect removal.