METHOD OF IMPROVING LIFETIME OF ETCHING LIQUID AND YIELD IN CU-INTERCONNECTION PROCESS AND CU-INTERCONNECTION ETCHING DEVICE

摘要

A Cu-interconnection etching device includes an etching liquid tank containing therein an etching liquid that is a hydrogen peroxide based solution, a first concentration monitoring device receiving the etching liquid from the etching liquid tank and measuring a copper ion concentration of the etching liquid. The etching liquid is supplied through a filter assembly that filters off copper ions contained in the etching liquid so as to provide a filtered etching liquid. The filter etching liquid is supplied through a second concentration monitoring device that measures a copper ion concentration of the filtered etching liquid and conducts the filtered etching liquid back to the etching liquid tank. A variation between the measurements of the first and second concentration monitoring devices is used to control the operation of the filter assembly in order to maintain a proper level of copper ion concentration in the etching liquid.

主权项

1. A Cu-interconnection etching device, comprising:
an etching liquid tank containing therein an etching liquid; a first concentration monitoring device that measures a copper ion concentration of the etching liquid in the etching liquid tank and operating a filter assembly arranged downstream the etching liquid tank to receive the etching liquid from the etching liquid tank and filtering copper ions from the etching liquid received thereby so as to provide a filtered etching liquid; and a second concentration monitoring device that is arranged downstream the filter assembly to measure a copper ion concentration of the filtered etching liquid and conducts the filtered etching liquid back to the etching liquid tank, wherein the first concentration monitoring device provides a first measurement of copper ion concentration of the etching liquid that is measured upstream the filter and the second concentration monitoring device provides a second measurement of copper ion concentration of the filtered etching liquid that is measured downstream the filter and a variation between the first and second measurements is applied to control the operation of the filter assembly for filtering copper ions from the etching liquid received from the etching liquid tank.