Paper EM-ThP27
Voltage-Activated Electrochemical Reaction of Cu Electrode for Electrochemical Chemical Mechanical Polishing (ECMP) Application

Thursday, October 18, 2007, 5:30 pm, Room 4C

The chemical mechanical polishing (CMP) process has been widely used to obtain global planarization of inter-metal dielectric (IMD) layers, inter-layer dielectric layers (ILD) and pre-metal dielectric (PMD) layers. Also, several semiconductor device and materials manufacturers have used this method. Especially, copper CMP has become an integral part of multilevel interconnection process. However, for the fabrication of 65nm and beyond technology nodes with fragile low k dielectric and copper, the down force of CMP process must be greatly reduced or eliminated to manage the low mechanical strength of low k film. To overcome these problems, we developed a new planarization technology that uses electrolyte chemistry instead of abrasive slurry. The current-voltage (I-V) curves were employed, in this paper, to evaluate the effect of electrolyte concentration on the reaction trend. From the I-V curve, the electrochemical states of active, passive, transient, and trans-passive could be characterized. The scanning electron microscopy (SEM) was used to observe the surface profile. The energy dispersive spectroscopy (EDS) spectrum was employed to analyze metallurgical components on the surface. From these analyses, it was important to understand the electrochemical mechanisms of the electrochemical chemical mechanical polishing (ECMP) technology. This work was supported by grant No. (R01-2006-000-11275-0) from the Basic Research Program of the Korea Science & Engineering Foundation and by Korea Research Foundation Grant (KRF-2006-005-J00902).