Liangxing Hu, S. Goh, J. Tao, Y. Lim, P. Zhao, Michael Joo Zhong Lim, C. S. Tan
{"title":"In-Depth Parametric Study of Ar or N2 Plasma Activated Cu Surfaces for Cu-Cu Direct Bonding","authors":"Liangxing Hu, S. Goh, J. Tao, Y. Lim, P. Zhao, Michael Joo Zhong Lim, C. S. Tan","doi":"10.1109/ECTC32696.2021.00077","DOIUrl":null,"url":null,"abstract":"In this article, we report in-depth parametric study of argon/nitrogen plasma-activated copper surfaces for copper-copper die-to-die direct bonding carried out at room temperature in cleanroom ambient condition. Surface analyses (e.g. water contact angle and X-ray photoelectron spectroscopy) are performed on the control, argon or nitrogen plasma-activated copper surfaces. The results reveal that a thin layer of copper nitride is formed on the copper surface with the nitrogen plasma treatment, which is a potentially effective passivation layer to control the surface oxidation. By fine-tuning the argon or nitrogen plasma (exposure time, plasma power and plasma species), a bonding strength of ∼6 MPa is achieved, and the bonded interface has a specific contact resistivity of $\\sim 6.0\\times 10^{-4}\\ \\Omega \\cdot \\text{cm}^{2}$. Therefore, an optimal plasma recipe is obtained for argon/nitrogen plasma-activated copper-copper direct bonding. This bonding technique is suitable for high-throughput three-dimensional wafer bonding and advanced packaging.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/ECTC32696.2021.00077","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 4
Abstract
In this article, we report in-depth parametric study of argon/nitrogen plasma-activated copper surfaces for copper-copper die-to-die direct bonding carried out at room temperature in cleanroom ambient condition. Surface analyses (e.g. water contact angle and X-ray photoelectron spectroscopy) are performed on the control, argon or nitrogen plasma-activated copper surfaces. The results reveal that a thin layer of copper nitride is formed on the copper surface with the nitrogen plasma treatment, which is a potentially effective passivation layer to control the surface oxidation. By fine-tuning the argon or nitrogen plasma (exposure time, plasma power and plasma species), a bonding strength of ∼6 MPa is achieved, and the bonded interface has a specific contact resistivity of $\sim 6.0\times 10^{-4}\ \Omega \cdot \text{cm}^{2}$. Therefore, an optimal plasma recipe is obtained for argon/nitrogen plasma-activated copper-copper direct bonding. This bonding technique is suitable for high-throughput three-dimensional wafer bonding and advanced packaging.