AVS 52nd International Symposium
    Manufacturing Science and Technology Tuesday Sessions
       Session MS-TuP

Paper MS-TuP5
Optimized Cu Electrochemical Plating considering Pattern Dependency in Dual-Damascene Process

Tuesday, November 1, 2005, 4:00 pm, Room Exhibit Hall C&D

Session: Topics in Advanced Manufacturing Poster Session
Presenter: H.-Y. Yoo, Chung-Ang University, Korea
Authors: H.-Y. Yoo, Chung-Ang University, Korea
N.-H. Kim, Chosun University, Korea
S.-Y. Kim, DongbuAnam Semiconductor Inc.
E.-G. Chang, Chung-Ang University, Korea
Correspondent: Click to Email
Since damascene technology announced, Cu metallization using electrochemical plating (ECP) has played an important role in back end of line interconnect formation. In damascene process, the problems related with process integration as well as with each unit process are becoming critical issues. Occurrence of step height (SH) and array height (AH) after Cu plating was closely related with pattern dependencies in Cu ECP and influenced in Cu chemical mechanical polishing (CMP) process. So, Cu plating target thickness in Cu ECP process was required to be optimized. In this work, we studied the optimized copper thickness in Cu ECP. In order to select an optimized Cu ECP thickness, we examined Cu ECP bulge (bump, hump or over-plating amount), Cu CMP dishing and electrical properties of via hole and line trench over dual damascene patterned wafers split into different ECP Cu thickness. In the aspect of bump and dishing, the bulge increased according as target plating thickness decreased. Dishing of edge was larger than center of wafer. Also in case of electrical property, metal line resistance distribution became broad gradually according as Cu ECP thickness decreased. In the results, 0.6 @micron@ plating condition that baseline size reduced 40% showed bad property in broad resistance distribution of metal line and dishing after Cu CMP process. In conclusion, at least 20% reduced Cu ECP thickness from current baseline; 0.8 @micron@ and 1.0 @micron@ are suitable to be adopted as newly optimized Cu ECP thickness for local and intermediate layer. Acknowledgement : This work was supported by grant No. R01-2002-000-00375-0 from the Basic Research Program of the Korea Science & Engineering Foundation.