A device includes a photonic cryo die containing photonic components, and an electronic die bonded to the photonic die, the electronic die containing electrically conductive through substrate vias. The electrically conductive through silicon vias can electrically connect a backside redistribution layer to control circuitry for operation in a cryogenic environment in a compact package that exhibits low resistance and low parasitic capacitance.

A device includes a photonic cryo die containing photonic components, and an electronic die bonded to the photonic die, the electronic die containing electrically conductive through substrate vias. The electrically conductive through silicon vias can electrically connect a backside redistribution layer to control circuitry for operation in a cryogenic environment in a compact package that exhibits low resistance and low parasitic capacitance.

A semiconductor device includes a substrate. A semiconductor die is disposed over the substrate. An encapsulant is deposited over the substrate and semiconductor die. A first trench is formed in the encapsulant over the semiconductor die. A second trench is formed completely through the encapsulant and substrate. A conductive layer is formed over the encapsulant and into the first trench and second trench.

A semiconductor device includes a substrate. A semiconductor die is disposed over the substrate. An encapsulant is deposited over the substrate and semiconductor die. A first trench is formed in the encapsulant over the semiconductor die. A second trench is formed completely through the encapsulant and substrate. A conductive layer is formed over the encapsulant and into the first trench and second trench.