Semiconductor device structure and method for forming the same

A semiconductor device structure, comprising:

• a semiconductor substrate having a first surface, a second surface, and sidewalls defining a recess that passes through the semiconductor substrate;
• an interconnect structure comprising one or more interconnect layers within a first dielectric structure disposed along the second surface;
• a nickel layer in the recess and electrically connected to the interconnect structure;
• a gold layer arranged over the nickel layer;
• an insulating layer lining the sidewalls of the semiconductor substrate defining the recess, wherein the gold layer has a top surface that is recessed below a top surface of the insulating layer, and wherein a top of the nickel layer contacts a bottom of the gold layer along an interface that extends along a horizontal line extending through sidewall of the insulating layer;
• and
• wherein the nickel layer has opposing outermost sidewalls that contact sidewalls of the interconnect structure.

A method for forming a semiconductor device structure, comprising:

• forming a first interconnect layer within a first dielectric structure disposed along a first surface of a semiconductor substrate;
• forming a recess in the semiconductor substrate, wherein the recess passes through the semiconductor substrate;
• forming an insulating layer lining interior sidewalls of the semiconductor substrate that define the recess;
• forming a bonding pad over the insulating layer;
• selectively etching the insulating layer, wherein the bonding pad acts as a mask that blocks etching of the insulating layer directly below the bonding pad;
• and
• forming a nickel layer over the first interconnect layer and within the recess, wherein the nickel layer is laterally separated from the semiconductor substrate by the insulating layer and is electrically coupled to the first interconnect layer.