版图图形特征对铜电镀工艺的影响

铜电镀工艺后表面的不平整度通常取决于版图关键特征，包括线宽，线间距和金属密度。本文设计了一款测试芯片并在一家半导体厂加工制造。版图特征效应被真正的测试数据所检查和验证。通过分析金属蝶形、介质腐蚀、金属厚度和SEM照片，得出一些结论。线宽是决定表面形貌及产生铜金属蝶形和介质层腐蚀的最关键因素。经过铜电镀工艺发现，铜线越细铜生长的越厚，铜线越宽铜金属蝶形越大，发现了3种典型表面形貌。而且，通过测试数据，量化版图特征的影响并用曲率增强加速剂覆盖率的理论解释，这可以用于开发铜电镀工艺模型和开展可制造性设计研究。

Effects of pattern characteristics on the copper electroplating process

The non-planarity of a surface post electroplating process is usually dependent on variations of key layout characteristics including line width, line spacing and metal density. A test chip is designed and manufactured in a semiconductor foundry to test the layout dependency of the electroplating process. By checking test data such as field height, array height, step height and SEM photos, some conclusions are made. Line width is a critical factor of topographical shapes such as the step height and height difference. After the electroplating process, the fine line has a thicker copper thickness, while the wide line has the greatest step height. Three typical topographies, conformal-fill, supper-fill and over-fill, are observed. Moreover, quantified effects are found using the test data and explained by theory, which can be used to develop electroplating process modeling and design for manufacturability (DFM) research.