Post CMP Waste Treatment
Professor Yuzhuo Li and his student Ping Wu, in collaboration
with Professor Ning Gao of St. Lawrence University and Dr.
George Chen of Persee Chemical Inc., are exploring new methods
for CMP waste treatment. Due to the increased complexity
of the CMP process and slurry composition, treatment of
the post CMP waste stream has become an integral part of
CMP development and implementation. For copper CMP, various
conventional forms of treatment have been investigated such
as coagulation and filtration. In this study, Professor
Li and his team implemented an innovative design that involves
the integrated utilization of the photocatalytic redox nature
of some semiconductor particles. More specifically, the
organic components are degraded by photo-oxidative processes.
Metal ions such as copper are then recovered or removed
from the waste stream by a photo-reductive route. The focus,
of more recent investigations, includes a degradation mechanism
of some key organic ingredients in a model copper CMP waste
stream and a possible integration scheme that couples the
recovery of metal ions and the removal of organic materials.
Preliminary results of this study will be presented at SEMICON
West in July 2003.
Professors Complete NSF Multimedia Development Project
1. Illustration of the chemical- mechanical planarization
Professors Ian Suni, Don Rasmussen, S.V. Babu ( also Vice
Provost & CAMP Director), and Raymond Mackay have just completed
a multimedia development project funded by the National Science
Foundation (NSF). This project "Advanced Topics in Colloidal
Technology" was funded through the combined research curriculum
development (CRCD) program, which is designed to translate
recent research developments into curricula. This multimedia
project is available online at www.clarkson.edu/~thinfilm.
It has been used in several courses at Clarkson University
and at other schools. Its topics, which reflect the faculty
research interests, include chapters on chemical-mechanical
planarization (See Figure 1.), semiconductor particle contamination,
particle size measurement by laser light scattering, and surfactant
behavior. (The first two topics mentioned above, which are
of critical importance for advanced semiconductor manufacturing,
are included only superficially in most semiconductor processing
textbooks.) In addition, a virtual scanning electron microscope
(SEM) was developed as an aid for students learning to use
this instrument at Clarkson. The capability for creating such
software can be used in the future in conjunction with the
industrial short courses offered through CAMP and/or for corporate-sponsored
continuing education projects.