In-situ end point detection of the STI-CMP process using a high selectivity slurry
✍ Scribed by Sang-Yong Kim; Kyoung-Jin Lee; Yong-Jin Seo
- Book ID
- 104305791
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 364 KB
- Volume
- 66
- Category
- Article
- ISSN
- 0167-9317
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✦ Synopsis
We studied the end point detection (EPD) for the direct CMP of the STI structure without the reverse moat etch process. In this case, we applied a high selectivity slurry (HSS) that improves the silicon oxide removal rate and maximizes the oxide-to-nitride selectivity. Quite acceptable and reproducible EPD results could be obtained, and the wafer-to-wafer thickness variation was significantly reduced when compared with the conventional predetermined polishing time method without EPD. Therefore, it was possible to achieve a global planarization without the complicated reverse moat process. Furthermore, the problems caused by nitride residues in the active regions could be reduced by overpolishing of SiO , since Si N was hardly removed. As a result, the STI 2 3 4 CMP process could be dramatically simplified, the defect level reduced, and therefore the throughput, yield and stability of semiconductor device fabrication could be greatly improved.