Application of Bottom-Up Selective Growth Technology to Hybrid Bonding

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20426
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0302:Electrical and electronic engineering and related fields
• Research Institution: Yokohama National University
• Principal Investigator: Inoue Fumihiro 横浜国立大学, 大学院工学研究院, 准教授 (00908303)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 化学機械研磨

Outline of Final Research Achievements

We evaluated the polishing rates of interconnect metal, barrier metal, and dielectric films using electrochemical measurements to optimize the chemical mechanical polishing (CMP) for the planarization of hybrid surfaces. The surface corrosion state was significantly affected by the addition of H2O2 as an oxidizing agent in the interconnect metal, while the surface state change due to H2O2 addition was smaller for the barrier metal, indicating the formation of a passive state. During the actual CMP process, the addition of H2O2 resulted in a noticeable increase in the polishing rate for the Cu sample, and the difference in polishing rates between the Cu and Ta samples became larger. Based on these results, it was elucidated that the slurry used in this study is more suitable for the planarization of hybrid bonding surfaces when H2O2 is not added as an oxidizing agent, as the corrosion rates of Cu and Ta are similar.

Free Research Field

半導体プロセス

Academic Significance and Societal Importance of the Research Achievements

世界各国の半導体のIDM、ファウンダリーは微細化限界から「後工程」や「チップレット」をかなり重要視していることが伺える。今回の研究成果であるCu-Cuハイブリッド接合は半導体後工程の単なる1要素技術と捉えるべきではない。この技術は次世代の半導体製造において「前工程」と「後工程」をつなぎ、新たなチップレット集積を可能とする革新的なプロセスとなり得る工程であり、その中でも最も重要なプロセスを学術的アプローチでメカニズムの解明を達成した。