Smart Particles for Copper CMP

CAMP Professors Yuzhuo Li and Devon Shipp, Postdoctoral Associate Li Liu, and graduate student Krishnayya Cheemalapati, in collaboration with Dr. Stuart Hellring of PPG Industries (a CAMP Corporate Member), are investigating new chemistries in formulating copper CMP slurries. The surface properties of abrasive particles have a profound influence on CMP performance. This is particularly true for copper CMP. The slurry particles not only provide the needed mechanical abrasion but also chemically interact with formulation components, the metal surface, and the (molecular and particulate) materials at the polished surface and in the spent effluent. Therefore, it is important to understand the correlation between the surface properties of these particles and their behavior during copper CMP under various chemical conditions. Such an understanding can provide unique opportunities for abrasive particle innovation in design, synthesis, functionalization, and processing.

In this study, silica particles with high surface hydroxyl content and desirable particle size are functionalized to sense the chemical composition of the surface as well as the differential surface topography at feature size levels during CMP. These smart particles with tunable surface properties are designed to achieve desired planarity distance and surface quality by self-regulating their functional response. The surface treatment processes are amenable to industrial scale-up and do not compromise key performance metrics such as particle size, size distribution, material removal rate, copper-to-barrier selectivity, and slurry stability. The surface-treated smart particles do offer better performance in patterned wafer polishing. It is also implied that the surface-treated particles can reduce the risk of damage to low-k/copper-patterned wafers. Preliminary results were recently presented at CMP-MIC in Marina Del Rey, CA and at SEMICON China in Shanghai, China.

Abrasive-Free System for Cu CMP

CAMP Professor Yuzhuo Li and his team (graduate students Jason Keleher, Joe Zhao, and Craig Burkhard) are working closely with Dr. Bill Wojtczak of SACHEM (a CAMP Corporate Member) to investigate abrasive-free systems for copper CMP. By eliminating abrasive particles from the CMP process, either free or fixed to the pads, advantages such as fewer surface defects, lower burden on consumable handling, and easier post CMP clean can be obtained. In this study, Professor Li's team is focusing on the supramolecular design of solution formulation and on the impact of the polishing platform (rotary or orbital). Results will be presented at the Spring 2003 Materials Research Symposium (MRS).








CAMP Professors Offer Short Courses on Diverse Topics

CAMP Professors are offering a variety of short courses. Course descriptions are provided.

Specialty Short Course (May 5-8, 2003)
About Surfactant Use in Microelectronic Applications

CAMP Professors Yuzhuo Li, Don Rasmussen, and Chris Brancewicz will join industrial experts to offer the specialty short course, "Use of Surfactants in Microelectronic Applications." This intensive four-day lecture / laboratory course will be taught at Clarkson University May 5-8, 2003. The course deals with the basic concepts and practical applications of surfactant and colloid science for microelectronic research and development with an emphasis on process enhancement. It is intended for chemists, chemical engineers, and researchers who work in the area of solution and / or colloidal formulation for microelectronic applications such as CMP slurry development, post CMP clean, and waste treatment. Non-technical supervisory and management personnel may also find this course informative and useful.

In addition to lectures on basic concepts and strategies, the course provides the participants with valuable hands-on experience in formulating and evaluating surfactant systems with various phase behaviors. It also develops an in-depth understanding of the vital roles these structures play in colloidal dispersion formulations.

The lecture material includes information on how to use phase diagrams to understand the phase behavior of typical surfactants and to formulate and stabilize colloidal dispersions. The lecture component also prepares one to select the proper analytical techniques for phase behavior research and colloidal dispersion characterization.

In addition, the laboratory component provides the participants experience in the preparation of phase diagrams, the use of analytical techniques to determine structures in complex solutions, the use of different surfactants to prepare conductive electronic pastes, and in the precipitation of submicron metal powders.

For more information about this short course, please visit www.clarkson.edu/surfactant or contact Professor Yuzhuo Li at yuzhuoli@clarkson.edu.

NMR Short Course July 7-11, 2003 at Clarkson University

An intensive short course on nuclear magnetic resonance (NMR) spectroscopy will be taught at Clarkson University during the week of July 7-11, 2003. CAMP Professors Devon Shipp and Yuzhuo Li along with Professor Ken Coskran (SUNY Potsdam) will serve as the instructors. The course includes detailed theory and practice of NMR spectroscopy, from the very basic through complex multi-dimensional concepts. This course is designed to allow participants to become familiar with Clarkson's new Bruker Avance 400 NMR instrument. This state-of-the-art facility has multi-nuclear, multi-dimensional, solid-state gradient and variable temperature NMR capabilities.

NMR spectroscopy is the most powerful technique available for determining molecular structure. In addition, it is very useful for obtaining physical properties such as molecular dynamics in solution and diffusion coefficients. The technique is especially valuable to chemists, environmental scientists/engineers, materials scientists/engineers, biologists, biochemists, and chemical engineers. Clarkson's NMR short course includes the following topics: fundamentals of NMR, operation of FT-NMR spectrometers, pulse sequences, pulse calibration, probe tuning, 1D proton and 13C spectra (DEPT), homo-decoupling, 2D homo-nuclear experiments, 2D hetero-nuclear experiments, gradients and their applications.

For more information about this short course, please contact Professor Devon Shipp at dshipp@clarkson.edu.

Professional Training Short Courses offered at Wyeth Pharmaceuticals

CAMP Professor Yuzhuo Li and his colleagues are working closely with Dr. Greg Slack of Wyeth Pharmaceuticals to organize a number of short courses for professional training. These courses are being offered at Wyeth in Rouses Point, NY. In a one day short course on March 28, 2003, Professors Chris Brancewicz and Don Rasmussen provided the employees at Wyeth with training in the area of particle sizing. This short course instructed participants on how to select the right techniques to analyze various particles and how to properly interpret the results from commonly used techniques such as sieving, sedimentation, field flow fractionation, optical and electrical particle counting, QELS, Zetal potential, and molecular weight determination for polymers.

Professor Ning Gao (St. Lawrence University) and CAMP Professor Yuzhuo Li will offer a short course on modern spectroscopic techniques and their applications in pharmaceutical quality control. Selected topics for this course include atomic absorption, FT-IR microscopy, Raman spectroscopy, and fluorescence microscopy. Also the short course, "Pharmaceutical Chemistry" taught by CAMP Professor Anja Mueller, will be offered at Wyeth this summer. Its topics include formulation of drugs, bio-availability of drugs, drug absorption in the body, and pharmacokinetics. In addition the NMR short course (offered July 7-11, 2003 at Clarkson University) will be available to Wyeth employees.