Method of Forming a Bonded Structure

In an embodiment, a method of forming a bonded structure is provided. The method may include forming at least one first under bump metallurgy (UBM) structure on a first substrate, forming a first gold layer on the at least one first under bump metallurgy structure; forming a tin layer on the first gold layer, forming an indium layer on the tin layer, forming an inhibition layer configured to inhibit oxygen penetration on the indium layer, and forming at least one second under bump metallurgy structure on a second substrate, forming s second gold layer on the at least one second under bump metallurgy structure; and bringing the inhibition layer into contact with the second gold layer at a predetermined temperature to form a resultant intermetallic structure between the first substrate and the second substrate thereby bonding the first substrate to the second substrate and forming the bonded structure.