Study on Improving Dishing on STI Structure

Autor: Ding, Yi, Yan, Junhua, Wang, CongGang, Zhu, Yefang, Fang, JingXun
Zdroj: ECS Transactions; March 2013, Vol. 52 Issue: 1
Abstrakt: Abstract: As a front-end technology, shallow trench isolation ( STI ) is widely used in submicron nodes of IC manufacturing because of its high space utilization rate on device layout. Chemical mechanical polishing (CMP) is used to achieve planarization by polishing off the oxide on top of pad nitride in a STI structure. When STI-CMP process is completed, oxide in the trench would likely form dish-shaped structure (dishing), which negatively affects the process stability and device performance. Such negative effect becomes more significant when IC technology advancing to nanometer nodes. Thus dishing improvement in STI-CMP for nanometer technology attracts more and more attention. In this paper, we studied influences of polishing amounts, CMP pressure and some other factors on post STI-CMP dishing performance in 45/40nm node. It was concluded that increasing in oxide polishing amount can reduce dishing; decreasing polishing pressure can enhance robustness of endpoint detection but has negligible effects on dishing reduction.
Databáze: Supplemental Index