Authors: J.Y. Lin, Y.Y. Wang and C.C. Wan
Affilation: National Tsing Hua University, Taiwan
Pages: 252 - 255
Keywords: electroplating, CMP, orientation, pulse current, resistivity
Deposition of highly (111) oriented conductive layer is required for achieving better electromigration resistance and lower resistivity. Moreover, the amount of void defects decreases as the (111)/(200) ratio increases in CMP process. Hence, we investigated the influence of additives and pulse frequency on the resistivity and crystal orientation. As the pulse frequency is 100 Hz, higher ratio of (111)/(200) and lower resistivity in the present of additives is obtained. Furthermore, we propose a new deposition approach beneficial for polishing in CMP based on above optimal condition. Utilizing DC to fill the trenches in the first step previously, and then PC is applied to accomplish the whole deposition. The switched time was determined by series of filling experiments. After the switched time was determined, the whole deposition with the use of combination of DC and PC was preformed. The preformed result indicates that there is not improper during the new approach. As a result, this approach may be useful to profit CMP process.