Backside contact for thermal displacement in a multi-wafer stacked integrated circuit

An integrated circuit (IC) die comprising:

• a semiconductor substrate;
• a semiconductor device integrated on a frontside of the semiconductor substrate;
• an interconnect structure arranged on the frontside of the semiconductor substrate, coupled to the semiconductor device, and comprising interconnect vias and interconnect wires embedded within dielectric layers;
• a first bonding structure arranged over the interconnect structure;
• a second bonding structure arranged on a backside of the semiconductor substrate and comprising bonding wires and bonding vias within a bonding dielectric structure;
• and
• a backside contact arranged within the second bonding structure, wherein a top surface of the backside contact is thermally coupled to the backside of the semiconductor substrate, wherein the top surface of the backside contact is spaced from the frontside of the semiconductor substrate by the semiconductor substrate, and wherein the backside contact is thermally and electrically coupled to the second bonding structure.

A method of forming an integrated circuit, the method comprising:

• forming a semiconductor device on a frontside of a semiconductor substrate;
• forming an interconnect structure over the semiconductor device;
• forming a first bonding structure over the interconnect structure;
• depositing a second dielectric layer over a backside of the semiconductor substrate;
• patterning the second dielectric layer to form a first opening in the second dielectric layer, wherein the first opening exposes a surface of the backside of the semiconductor substrate, and wherein the surface of the backside of the semiconductor substrate is above the semiconductor device when the backside of the semiconductor substrate is above the frontside of the semiconductor substrate;
• depositing a glue layer having a first thickness over the first opening;
• filling the first opening with a first material to form a backside contact that is separated from the semiconductor substrate by the glue layer;
• and
• depositing more dielectric layers, bonding contacts, and bonding wire layers over the second dielectric layer to form a second bonding structure on the backside of the semiconductor substrate, wherein the backside contact is coupled to the bonding contacts and the bonding wire layers.