Low resistance hybrid bonded interconnects

Abstract

Methods for reducing the resistance of a contact leverage fine grain sizes to increase thermal expansion during hybrid bonding for increased bonding strength and fine grain growth after bonding to decrease resistance of the contact. In some embodiments, the method may comprise bonding a first contact on a first substrate to a second contact on a second substrate where a first end region of the first contact has a bonding surface and has a first average grain size that is smaller than a second average grain size of a second end region that is opposite of the first end region and where the first end region has grain boundary pinning additives in the first end region and driving the additives from the first end region to the second end region after bonding using a thermal treatment to promote grain growth within the first end region.

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