1. In Situ Pre-Metallization Cleaning of CoSi2 Contact-Hole Patterns with Optimized Etching Process
- Author
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Tae-Min Choi, Eun-Su Jung, Jin-Uk Yoo, Hwa-Rim Lee, Songhun Yoon, and Sung-Gyu Pyo
- Subjects
Ar sputtering ,plasma treatment ,pre-metallization cleaning ,plasma induce damage ,contact hole cleaning ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
We examined how controlling variables in a pre-metallization Ar sputter-etching process for in situ contact-hole cleaning affects the contact-hole profile, etching rate, and substrate damage. By adjusting process parameters, we confirmed that increasing plasma power lowered the DC bias but enhanced the etching rate of SiO2, while increasing RF power raised both, with RF power having a more pronounced effect. Higher Ar flow rate reduced etching uniformity and slightly lowered the DC bias. There was no significant difference in the amount of etching between the oxide film types, but the nitride/oxide selectivity ratio was about 1:2. Physical damage during Ar sputter-etching was closely linked to DC bias. finally, Finally, etching of the Si and CoSi2 sublayers was performed on the device contact hole model. At this time, Si losses of up to about 31.7 Å/s occurred, and the etch speed was strongly affected by the DC bias. By optimizing the RF power and plasma power, we achieved a Si/CoSi2 etch selectivity ratio of about 1:2.
- Published
- 2024
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