Pad Scratching in Chemical-Mechanical Polishing: The Effects of Mechanical and Tribological Properties
In chemical-mechanical polishing (CMP), even the soft pad asperities may, under certain conditions, generate scratches on the relatively hard surfaces being polished. In the present study, contact mechanics models of pad-induced scratching are formulated, and the effects of the hardness of the surfa...
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| Format: | Article |
| Language: | en_US |
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Electrochemical Society
2017
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| Online Access: | http://hdl.handle.net/1721.1/108056 https://orcid.org/0000-0002-3548-6173 https://orcid.org/0000-0002-8480-5572 https://orcid.org/0000-0003-1607-3581 |
| _version_ | 1826197157186633728 |
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| author | Kim, Sanha Saka, Nannaji Chun, Jung-Hoon |
| author2 | Massachusetts Institute of Technology. Laboratory for Manufacturing and Productivity |
| author_facet | Massachusetts Institute of Technology. Laboratory for Manufacturing and Productivity Kim, Sanha Saka, Nannaji Chun, Jung-Hoon |
| author_sort | Kim, Sanha |
| collection | MIT |
| description | In chemical-mechanical polishing (CMP), even the soft pad asperities may, under certain conditions, generate scratches on the relatively hard surfaces being polished. In the present study, contact mechanics models of pad-induced scratching are formulated, and the effects of the hardness of the surface layers and of pad asperities as well as the interfacial friction are elucidated. Additionally, scratch-regime maps are proposed to provide criteria for scratching hard surface layers by the softer pad asperities. Furthermore, scratching indexes are introduced to predict the proportion of asperities in contact that are likely to scratch. The contact mechanics models of scratching have been validated by sliding experiments with two commercial CMP pads (Pad A and IC1000) and various thin-films (Al, Cu, SiO[subscript 2], Si[subscript 3]N[subscript 4], TiN and three low-k dielectrics) using deionized water as a “lubricant.” Both the theoretical models and the experimental results show that the number of scratches increases as the scratching index exceeds 0.33. Al and Cu layers are found to be more susceptible to pad scratching due to their low hardness and high interfacial friction. The scratch-regime maps provide practical guidelines for mitigating pad scratching in CMP. |
| first_indexed | 2024-09-23T10:43:41Z |
| format | Article |
| id | mit-1721.1/108056 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:43:41Z |
| publishDate | 2017 |
| publisher | Electrochemical Society |
| record_format | dspace |
| spelling | mit-1721.1/1080562022-09-27T14:33:39Z Pad Scratching in Chemical-Mechanical Polishing: The Effects of Mechanical and Tribological Properties Kim, Sanha Saka, Nannaji Chun, Jung-Hoon Massachusetts Institute of Technology. Laboratory for Manufacturing and Productivity Kim, Sanha Saka, Nannaji Chun, Jung-Hoon In chemical-mechanical polishing (CMP), even the soft pad asperities may, under certain conditions, generate scratches on the relatively hard surfaces being polished. In the present study, contact mechanics models of pad-induced scratching are formulated, and the effects of the hardness of the surface layers and of pad asperities as well as the interfacial friction are elucidated. Additionally, scratch-regime maps are proposed to provide criteria for scratching hard surface layers by the softer pad asperities. Furthermore, scratching indexes are introduced to predict the proportion of asperities in contact that are likely to scratch. The contact mechanics models of scratching have been validated by sliding experiments with two commercial CMP pads (Pad A and IC1000) and various thin-films (Al, Cu, SiO[subscript 2], Si[subscript 3]N[subscript 4], TiN and three low-k dielectrics) using deionized water as a “lubricant.” Both the theoretical models and the experimental results show that the number of scratches increases as the scratching index exceeds 0.33. Al and Cu layers are found to be more susceptible to pad scratching due to their low hardness and high interfacial friction. The scratch-regime maps provide practical guidelines for mitigating pad scratching in CMP. Samsung (Firm) 2017-04-11T19:13:09Z 2017-04-11T19:13:09Z 2014-04 2014-03 Article http://purl.org/eprint/type/JournalArticle 2162-8769 2162-8777 http://hdl.handle.net/1721.1/108056 Kim, S., N. Saka, and J.-H. Chun. “Pad Scratching in Chemical-Mechanical Polishing: The Effects of Mechanical and Tribological Properties.” ECS Journal of Solid State Science and Technology 3.5 (2014): P169–P178. https://orcid.org/0000-0002-3548-6173 https://orcid.org/0000-0002-8480-5572 https://orcid.org/0000-0003-1607-3581 en_US http://dx.doi.org/10.1149/2.027405jss ECS Journal of Solid State Science and Technology Creative Commons Attribution 4.0 International License http://creativecommons.org/licenses/by/4.0/ application/pdf Electrochemical Society Electrochemical Society |
| spellingShingle | Kim, Sanha Saka, Nannaji Chun, Jung-Hoon Pad Scratching in Chemical-Mechanical Polishing: The Effects of Mechanical and Tribological Properties |
| title | Pad Scratching in Chemical-Mechanical Polishing: The Effects of Mechanical and Tribological Properties |
| title_full | Pad Scratching in Chemical-Mechanical Polishing: The Effects of Mechanical and Tribological Properties |
| title_fullStr | Pad Scratching in Chemical-Mechanical Polishing: The Effects of Mechanical and Tribological Properties |
| title_full_unstemmed | Pad Scratching in Chemical-Mechanical Polishing: The Effects of Mechanical and Tribological Properties |
| title_short | Pad Scratching in Chemical-Mechanical Polishing: The Effects of Mechanical and Tribological Properties |
| title_sort | pad scratching in chemical mechanical polishing the effects of mechanical and tribological properties |
| url | http://hdl.handle.net/1721.1/108056 https://orcid.org/0000-0002-3548-6173 https://orcid.org/0000-0002-8480-5572 https://orcid.org/0000-0003-1607-3581 |
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