High Rate Ceria Slurry and Pad Combo Solution for Bulk Oxide CMP

Ceria particles have been widely used in CMP (chemical mechanical planarization) on both STI (shallow trench isolation) and ILD (Inner layer dielectric) applications. For bulk oxide step polishing, high removal rate is always considered to be one of the most important factors. To achieve high removal rate, most ceria slurries are designed to have high solid level. Aggressive CMP conditions are often used during bulk oxide polishing. High solid level and aggressive CMP condition contribute a lot of consumable lifetime issues, such as pad life and conditioner disk decay. High solid level also contributes more chances of scratch count at the end of polishing. To balance high throughput and long consumable lifetime and other pattern wafer CMP performance, we proposed a combo solution for bulk oxide polishing. The polishing slurry is used low solid level ceria slurry and new pad material to achieve the high oxide removal rate.