Blakely, Sokoloff, Taylor & Zafman LLP
Using cell voltage as a monitor for deposition coverage
A method and apparatus are described that use cell voltage and/or current as monitor to prevent electrochemical deposition (e.g., electroplating) tools from deplating wafers with no or poor metal (e.g., Cu) seed coverage. In one embodiment, the voltage of a plating cell including a reference wafer which has substantially complete Cu seed coverage is measured. A reference resistance of the plating cell with the reference wafer is determined. The voltage of the plating cell including a calibration wafer which has no or insufficient seed coverage at its edge is measured. A calibration resistance of the plating cell with the calibration wafer is determined. An error trigger based on a comparison of the reference resistance with the calibration resistance is selected.
Intel Corporation
H C
H01L C25D
additional inventional
Yue Yang Jir-shyr Rajiv
Ma Cao Chen Rastogi