In an embodiment, a device includes: an interposer; a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a buffer layer around the first integrated circuit device and the second integrated circuit device, the buffer layer including a stress reduction material having a first Young's modulus; and an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant including a molding material having a second Young's modulus, the first Young's modulus less than the second Young's modulus.

In an embodiment, a device includes: an interposer; a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a buffer layer around the first integrated circuit device and the second integrated circuit device, the buffer layer including a stress reduction material having a first Young's modulus; and an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant including a molding material having a second Young's modulus, the first Young's modulus less than the second Young's modulus.

In an embodiment, a device includes: an interposer; a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a buffer layer around the first integrated circuit device and the second integrated circuit device, the buffer layer including a stress reduction material having a first Young's modulus; and an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant including a molding material having a second Young's modulus, the first Young's modulus less than the second Young's modulus.

In an embodiment, a device includes: an interposer; a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a buffer layer around the first integrated circuit device and the second integrated circuit device, the buffer layer including a stress reduction material having a first Young's modulus; and an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant including a molding material having a second Young's modulus, the first Young's modulus less than the second Young's modulus.

The present application provides a method for fabricating a semiconductor device. The method includes providing a carrier substrate, forming through semiconductor vias in the carrier substrate for thermally conducting heat, forming a bonding layer on the carrier substrate, providing a first die structure including through semiconductor vias, forming an intervening bonding layer on the first die structure, bonding the first die structure onto the bonding layer through the intervening bonding layer, and bonding a second die structure onto the first die structure. The carrier substrate, the through semiconductor vias, and the bonding layer together configure a carrier structure. The second die structure and the first die structure are electrically coupled by the through semiconductor vias.

The present application provides a method for fabricating a semiconductor device. The method includes providing a carrier substrate, forming through semiconductor vias in the carrier substrate for thermally conducting heat, forming a bonding layer on the carrier substrate, providing a first die structure including through semiconductor vias, forming an intervening bonding layer on the first die structure, bonding the first die structure onto the bonding layer through the intervening bonding layer, and bonding a second die structure onto the first die structure. The carrier substrate, the through semiconductor vias, and the bonding layer together configure a carrier structure. The second die structure and the first die structure are electrically coupled by the through semiconductor vias.

In an embodiment, a device includes: an interposer; a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a buffer layer around the first integrated circuit device and the second integrated circuit device, the buffer layer including a stress reduction material having a first Young's modulus; and an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant including a molding material having a second Young's modulus, the first Young's modulus less than the second Young's modulus.

In an embodiment, a device includes: an interposer; a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a buffer layer around the first integrated circuit device and the second integrated circuit device, the buffer layer including a stress reduction material having a first Young's modulus; and an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant including a molding material having a second Young's modulus, the first Young's modulus less than the second Young's modulus.

In described examples, a microelectronic device includes a microelectronic die with a die attach surface. The microelectronic device further includes a nanoparticle layer coupled to the die attach surface. The nanoparticle layer may be in direct contact with the die attach surface, or may be coupled to the die attach surface through an intermediate layer, such as an adhesion layer or a contact metal layer. The nanoparticle layer includes nanoparticles having adjacent nanoparticles adhered to each other. The microelectronic die is attached to a package substrate by a die attach material. The die attach material extends into the nanoparticle layer and contacts at least a portion of the nanoparticles.

In described examples, a microelectronic device includes a microelectronic die with a die attach surface. The microelectronic device further includes a nanoparticle layer coupled to the die attach surface. The nanoparticle layer may be in direct contact with the die attach surface, or may be coupled to the die attach surface through an intermediate layer, such as an adhesion layer or a contact metal layer. The nanoparticle layer includes nanoparticles having adjacent nanoparticles adhered to each other. The microelectronic die is attached to a package substrate by a die attach material. The die attach material extends into the nanoparticle layer and contacts at least a portion of the nanoparticles.