SBIR Phase I: Acoustic Slurry Monitor

This SBIR Phase-I project is to develop an acoustic CMP (Chemical Mechanical Polishing) slurry monitor?a fully in-line, real-time, point of use instrument that will detect and disperse any and all large agglomerates in the nanofine slurries used in IC manufacture. Left unchecked, these errant slurry particles/ agglomerates can "kill" (deeply scratch) a semiconductor wafer as it undergoes chemical mechanical planarizing or polishing. CMP has become the method of choice for restoring the surface trueness of wafers at all stages of IC manufacture. This acoustic slurry monitor makes use of a novel technology?Acoustic Coaxing Induced Microcavitation (ACIM), a means of constructively controlling acoustic microcavitation. It does so by facilitating controlled bubble nucleation preferentially on the large particle, in the midst of dense nano-fine slurry. This research is thus aimed at investigating a new principle of bubble nucleation. In operation the slurry monitor will inspect a 100ml of the slurry charge at final dispense point just before the slurry is fed to the polishing pad. It will complete the detection for large particles in fully dense CMP slurry in one minute. This slurry monitor can be mounted on the existing CMP tools. The broader impact/commercial potential of this project are to enable improved yields in semiconductor manufacturing by making CMP processing scratch free. No method currently exists that can implement a CMP-safe slurry at the point of use. An advanced device wafer scratched at the final stages of manufacture is a direct loss of $250k or more. Use of the Acoustic Slurry Monitor protects wafers and more than returns the $100k investment with the very first wafer it saves. The Slurry Monitor is a yield protecting tool reliably improving CMP performance. Ultimately, the principle of constructively controlled microcavitation, ACIM particle detection, relies on controlling the very fundamental process of phase change, the control of nucleation?the ability to convert a liquid into a gas in the vicinity of a solid phase. The study of this acoustically mediated nucleation control could form an active field/area of research and education. ACIM will be widely applicable in a variety of liquid-chemical processing, e.g. control of boiling processes in chemical and nuclear reactors, sonochemical synthesis, and bio-technology. This small business is a minority and woman-owned company that relies on diversity?ethnic, gender and age?for robust performance that is dedicated to training young researchers.