SBIR Phase I: Novel Slurry Injector Device for Chemical Mechanical Planarization Application

This Small Business Innovation Research (SBIR) Phase I project will develop and implement a novel slurry injection device for applications in chemical mechanical planarization (CMP), a key-enabling technology for integrated circuit (IC) manufacturing. In the most current CMP commercial polishers, the slurry is injected on the pad center area during wafer polishing. As a large amount of fresh slurry flows directly off the pad surface without entering the pad-wafer interface and reacting with the wafer surface, it results in very low slurry utilization. In addition, spent slurry containing polishing by-products and residual de-ionized water from the pad rinsing step can mix with the fresh slurry during polishing, causing lower material removal rates and higher polishing defects. In this project, a novel slurry injection device is being developed and implemented for different commercial CMP polishers, and the slurry injector polishing performance will be evaluated. The novel slurry injection device designed is expected to not only increase the slurry utilization efficiency by injecting the fresh slurry to where it is needed (pad-wafer interface), but also enhance the removal rate and reduce polishing defects by blocking the spent slurry and residue from re-entering the pad-wafer interface during wafer polishing. The commercial potential of this project is a significant reduction in the cost of ownership (COO) of the CMP module and making CMP processes more environmentally benign for the IC manufacturing industry. Among the consumables used in CMP processes, slurries may account for up to 50% of the total COO for the CMP module. In addition, slurry consumption has tremendous environmental impacts as waste slurries can contain hazardous chemicals and metal contents with large amounts of nanosized abrasive particles. Through more efficient slurry delivery and minimum slurry mixing and dilution, the novel slurry injection device designed can achieve the same material removal rate and fewer polishing defects with significantly lower slurry consumption. As the slurry consumption is reduced, less waste slurry is generated. Therefore, the novel slurry injector device will not only reduce the COO of CMP processes for IC manufacturers, but also make the CMP processes more environmentally benign.