Heat dissipation in semiconductor devices

A device comprising:

• a first transistor structure and a second transistor structure in a device layer;
• an interconnect structure on the device layer, the first transistor structure being electrically coupled to the second transistor structure through the interconnect structure;
• a first bonding layer on the interconnect structure, wherein the first bonding layer comprises first metal nano-particle aggregates, and wherein each of the first metal nano-particle aggregates comprises first metal nano-particles;
• a substrate;
• and
• a second bonding layer on the substrate, wherein the second bonding layer comprises second metal nano-particle aggregates, wherein each of the second metal nano-particle aggregates comprises second metal nano-particles, wherein the first metal nano-particles and the second metal nano-particles comprise different materials, and wherein the substrate is directly bonded to the interconnect structure by the first bonding layer and the second bonding layer.

A method comprising:

• forming a device layer on a semiconductor substrate, the device layer comprising a transistor;
• forming an interconnect structure over the device layer;
• depositing a first bonding layer on the interconnect structure, wherein the first bonding layer comprises a first base layer and first metal nano-particles embedded in the first base layer, wherein the first metal nano-particles are surrounded by the first base layer, and wherein the first base layer and the first metal nano-particles comprise different materials;
• and
• directly bonding the first bonding layer to a second bonding layer by dielectric-to-dielectric bonding, wherein the second bonding layer is on a substrate before bonding the first bonding layer to the second bonding layer, wherein the second bonding layer comprises a second base layer and second metal nano-particles embedded in the second base layer, and wherein the second metal nano-particles are surrounded by the second base layer.