Layer by layer electro chemical plating (ECP) process

摘要

The present disclosure relates to an electro-chemical plating (ECP) process that provides for an isotropic deposition, and a related apparatus. In some embodiments, the disclosed ECP process is performed by providing a substrate into an electroplating solution comprising a plurality of ions of a material to be deposited. A periodic patterned signal, which alternates between a first value and a different second value, is applied to the substrate. When the periodic patterned signal is at the first value, ions from the electroplating solution affix to the substrate. When the periodic patterned signal is at the second value, ions from the electroplating solution do not affix to the substrate. By using the periodic patterned signal to perform electro-chemical plating, the deposition rate of the plating process is reduced, resulting in an isotropic deposition over the substrate that mitigates gap fill problems (e.g., void formation).

主权项

1. A method of electro-chemical plating, comprising:
providing a substrate have a trench into an electroplating solution comprising a plurality of ions of a material to be deposited; filling the trench with a plurality of deposited layers, which respectively have a uniform thickness of the material along sidewalls and a lower surface of the trench, wherein each of the plurality of deposited layers are formed during separate operating periods of a periodically patterned signal comprising a square waveform that transitions from a second voltage to a first voltage at an end of each of the plurality of operating periods, and wherein the separate operating periods respectively comprise a first phase in which the first voltage is applied to a cathode in electrical contact with the substrate to attract one or more of the plurality of ions from the electroplating solution to the substrate and a second phase in which the second voltage is applied to the cathode to dissociate deposited ions from the substrate back into the electroplating solution; and dynamically varying one or more parameters of the square waveform including: a maximum voltage or a minimum voltage.