Use of dilute hydrochloric acid in advanced interconnect contact clean in nickel semiconductor technologies

Abstract

A method for cleaning oxide from the interconnects of a semiconductor that are comprised of nickel (Ni) silicide or nickel-silicide alloys where nickel is the primary metallic component is disclosed. The cleaning comprises performing an SC1 cycle, exposing the wafer comprising a NiSi contact to an SC1 solution. This removes oxygen atoms from the silicon oxide of the nickel silicide. Next, a rinse cycle is performed on the wafer to remove the SC1 solution. Finally, an HCl cycle is performed. During this cycle, the wafer comprising an NiSi contact is introduced to an HCl solution, removing oxygen atoms from the nickel oxide of the NiSi. The method of the present invention provides for lower contact resistance of NiSi semiconductor devices, facilitating semiconductor devices that have the benefits of miniaturization allowed by the NiSi technology, and higher performance due to the reduced contact resistance.