	US 12,354,911 B2
	Cu₃Sn via metallization in electrical devices for low-temperature 3D-integration
Andrew Clarke, Santa Barbara, CA (US); John J. Drab, Arroyo Grande, CA (US); and Faye Walker, Lompoc, CA (US)
Assigned to Raytheon Company, Arlington, VA (US)
Filed by Raytheon Company, Tewksbury, MA (US)
Filed on Dec. 11, 2023, as Appl. No. 18/535,536.
Application 18/535,536 is a division of application No. 17/184,756, filed on Feb. 25, 2021, granted, now 11,854,879.
Claims priority of provisional application 62/982,020, filed on Feb. 26, 2020.
Prior Publication US 2024/0203790 A1, Jun. 20, 2024
Int. Cl. H01L 21/768 (2006.01); H01L 23/522 (2006.01); H01L 23/528 (2006.01); H01L 23/532 (2006.01)

CPC H01L 21/76883 (2013.01) [H01L 21/76802 (2013.01); H01L 21/76886 (2013.01); H01L 23/5226 (2013.01); H01L 23/528 (2013.01); H01L 23/53233 (2013.01)]

20 Claims

1. An electrical device, comprising:

a substrate;

an electrically conductive trace at least partially overlying the substrate;

an electrically conductive interconnect disposed in a via hole, wherein the electrically conductive interconnect is electrically connected to the trace; and

a bonding layer at least partially surrounding the interconnect and at least partially overlying the substrate and the electrically conductive trace;

wherein the electrically conductive interconnect is made of Cu₃Sn; and

wherein the Cu₃Sn is formed by solid-state diffusion of Cu into Sn.