US 11,753,736 B2
Indium electroplating on physical vapor deposition tantalum
Michael J. Rondon, Santa Rosa, CA (US); Jon Sigurdson, Santa Barbara, CA (US); and Eric R. Miller, Orcutt, CA (US)
Assigned to RAYTHEON COMPANY, Waltham, MA (US)
Filed by Raytheon Company, Waltham, MA (US)
Filed on Nov. 16, 2020, as Appl. No. 17/98,560.
Prior Publication US 2022/0154359 A1, May 19, 2022
Int. Cl. C25D 7/12 (2006.01); C23C 14/18 (2006.01); C25D 3/54 (2006.01)
CPC C25D 7/12 (2013.01) [C23C 14/18 (2013.01); C25D 3/54 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method of fabricating a wafer stack, the method comprising:
forming a tantalum-nitride film on a substrate of the wafer stack using physical vapor deposition in a deposition chamber of a physical vapor deposition apparatus controlled by a deposition controller;
forming a tantalum layer on the tantalum-nitride film using physical vapor deposition in the deposition chamber controlled by the deposition controller, wherein the tantalum layer is at least three times thicker than the tantalum-nitride film, and an average sheet resistance of the tantalum layer and the tantalum-nitride film combined on the substrate is between 0.1 and 1.0 ohms-per-square; and
depositing indium directly on the tantalum layer using electroplating in an electroplating bath of an electroplating apparatus controlled by an electroplating controller.