Semiconductor devices and method for forming the same

A method, comprising:

• forming a fin over a front side of a substrate;
• forming a gate structure and source/drain structures over the fin;
• forming a front-side interconnect structure over the gate structure;
• forming a thermal conductive layer over a carrier substrate;
• forming a dielectric layer and bonding pads over the thermal conductive layer, wherein the thermal conductive layer has a higher thermal conductivity than the dielectric layer;
• and
• bonding the dielectric layer and bonding pads to the front-side interconnect structure.

A semiconductor device, comprising:

• a substrate;
• a transistor over a front side of the substrate, the transistor comprises a channel region, a gate structure over the channel region, and source/drain structures on opposite sides of the gate structure;
• a front-side interconnect structure over the transistor;
• a thermal conductive layer over the front-side interconnect structure, wherein the thermal conductive layer has a thermal conductivity higher than a dielectric layer of the front-side interconnect structure that is farthest from the substrate;
• and
• a backside interconnect structure over a backside of the substrate.