Analysis of CMP planarization performance for STI process

Autor: Manabu Tsujimura, Hisanori Matsuo, Masahiro Ota, Hirokuni Hiyama
Rok vydání: 2001
Předmět:
Zdroj: Journal of the Japan Society for Precision Engineering. 67:1289-1293
ISSN: 1882-675X
0912-0289
Popis: CMP has now been adopted not only for ILD and W-plug, but also for Cu metal and STI. In the STI CMP process, the wafer has some defined waviness, and it has recently been reported that this waviness may affect the STI CMP yield. The principle purpose of CMP is to planarize relatively with larger scale than small topography. Therefore, there may be a range of wafer topography in which the STI pattern may be over polished, depending on its peak-to-valley and frequency. The range and dishing performance of STI are calculated based on step height performance, which is in turn calculated by FEM. In this analysis, CMP is defined as four types of regions; the step height region in which the planarization performance of step height reduction is required, the uniform material region in which uniform polish is required, the non-uniform material region in which the planarization performance of dishing and erosion reduction is required and the substrate region in which defect reduction is required. The allowable peak-to-valley value and its frequency are calculated. It has also been reported that slurry selectivity can decrease this effect, together with disadvantage.
Databáze: OpenAIRE