Two-Step Plasma Treatment on Sputtered and Electroplated Cu Surfaces for Cu-To-Cu Bonding Application
The technology trends of next generation electronic packaging are moving toward heterogeneous 3D packaging systems. One of the key processes of 3D packaging system is Cu-to-Cu bonding, which is highly dependent on the planarized, activated, and oxygen-free Cu surface. A two-step plasma treatment is...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2019-08-01
|
| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/9/17/3535 |
| _version_ | 1828388034215673856 |
|---|---|
| author | Hankyeol Seo Hae Sung Park Sarah Eunkyung Kim |
| author_facet | Hankyeol Seo Hae Sung Park Sarah Eunkyung Kim |
| author_sort | Hankyeol Seo |
| collection | DOAJ |
| description | The technology trends of next generation electronic packaging are moving toward heterogeneous 3D packaging systems. One of the key processes of 3D packaging system is Cu-to-Cu bonding, which is highly dependent on the planarized, activated, and oxygen-free Cu surface. A two-step plasma treatment is studied to form a Cu surface that does not react with oxygen and improves the Cu bonding interface quality at low bonding temperature (300 °C). In this study, the effects of two-step plasma treatment on both sputtered and electroplated Cu surfaces were evaluated through structural, chemical, and electrical analysis. The Cu bonding interface was studied by scanning acoustic tomography analysis after the thermocompression bonding process. Both sputtered and electroplated Cu thin films had the preferred orientation of (111) plane, but sputtered Cu exhibited larger grains than the electroplated Cu. As a result, the roughness of sputtered Cu was lower, and the resistivity was higher than that of electroplated Cu. Based on X-ray photoelectron spectroscopy analysis, the sputtered Cu formed more copper nitrides and fewer copper oxides than the electroplated Cu. A significant improvement in bonding quality at the Cu bonded interface was observed in sputtered Cu. |
| first_indexed | 2024-12-10T06:05:33Z |
| format | Article |
| id | doaj.art-9fe78f7954814eec80ae3da37528d076 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-12-10T06:05:33Z |
| publishDate | 2019-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-9fe78f7954814eec80ae3da37528d0762022-12-22T01:59:43ZengMDPI AGApplied Sciences2076-34172019-08-01917353510.3390/app9173535app9173535Two-Step Plasma Treatment on Sputtered and Electroplated Cu Surfaces for Cu-To-Cu Bonding ApplicationHankyeol Seo0Hae Sung Park1Sarah Eunkyung Kim2Graduate School of Nano-IT Design Convergence, Seoul National University of Science and Technology, Seoul 01811, KoreaDepartment of Mechanical Engineering, Seoul National University of Science and Technology, Seoul 01811, KoreaGraduate School of Nano-IT Design Convergence, Seoul National University of Science and Technology, Seoul 01811, KoreaThe technology trends of next generation electronic packaging are moving toward heterogeneous 3D packaging systems. One of the key processes of 3D packaging system is Cu-to-Cu bonding, which is highly dependent on the planarized, activated, and oxygen-free Cu surface. A two-step plasma treatment is studied to form a Cu surface that does not react with oxygen and improves the Cu bonding interface quality at low bonding temperature (300 °C). In this study, the effects of two-step plasma treatment on both sputtered and electroplated Cu surfaces were evaluated through structural, chemical, and electrical analysis. The Cu bonding interface was studied by scanning acoustic tomography analysis after the thermocompression bonding process. Both sputtered and electroplated Cu thin films had the preferred orientation of (111) plane, but sputtered Cu exhibited larger grains than the electroplated Cu. As a result, the roughness of sputtered Cu was lower, and the resistivity was higher than that of electroplated Cu. Based on X-ray photoelectron spectroscopy analysis, the sputtered Cu formed more copper nitrides and fewer copper oxides than the electroplated Cu. A significant improvement in bonding quality at the Cu bonded interface was observed in sputtered Cu.https://www.mdpi.com/2076-3417/9/17/3535Cu bonding3D packagingnitrogen plasma treatmentcopper nitride passivationlow temperature thermo-compression bonding |
| spellingShingle | Hankyeol Seo Hae Sung Park Sarah Eunkyung Kim Two-Step Plasma Treatment on Sputtered and Electroplated Cu Surfaces for Cu-To-Cu Bonding Application Applied Sciences Cu bonding 3D packaging nitrogen plasma treatment copper nitride passivation low temperature thermo-compression bonding |
| title | Two-Step Plasma Treatment on Sputtered and Electroplated Cu Surfaces for Cu-To-Cu Bonding Application |
| title_full | Two-Step Plasma Treatment on Sputtered and Electroplated Cu Surfaces for Cu-To-Cu Bonding Application |
| title_fullStr | Two-Step Plasma Treatment on Sputtered and Electroplated Cu Surfaces for Cu-To-Cu Bonding Application |
| title_full_unstemmed | Two-Step Plasma Treatment on Sputtered and Electroplated Cu Surfaces for Cu-To-Cu Bonding Application |
| title_short | Two-Step Plasma Treatment on Sputtered and Electroplated Cu Surfaces for Cu-To-Cu Bonding Application |
| title_sort | two step plasma treatment on sputtered and electroplated cu surfaces for cu to cu bonding application |
| topic | Cu bonding 3D packaging nitrogen plasma treatment copper nitride passivation low temperature thermo-compression bonding |
| url | https://www.mdpi.com/2076-3417/9/17/3535 |
| work_keys_str_mv | AT hankyeolseo twostepplasmatreatmentonsputteredandelectroplatedcusurfacesforcutocubondingapplication AT haesungpark twostepplasmatreatmentonsputteredandelectroplatedcusurfacesforcutocubondingapplication AT saraheunkyungkim twostepplasmatreatmentonsputteredandelectroplatedcusurfacesforcutocubondingapplication |