Staged via formation from both sides of chip
A method of fabricating a semiconductor assembly can include providing a semiconductor element having a front surface, a rear surface, and a plurality of conductive pads, forming at least one hole extending at least through a respective one of the conductive pads by processing applied to the respective conductive pad from above the front surface, forming an opening extending from the rear surface at least partially through a thickness of the semiconductor element, such that the at least one hole and the opening meet at a location between the front and rear surfaces, and forming at least one conductive element exposed at the rear surface for electrical connection to an external device, the at least one conductive element extending within the at least one hole and at least into the opening, the conductive element being electrically connected with the respective conductive pad.
1. A semiconductor assembly, comprising:
a semiconductor element having a front surface, a rear surface remote from the front surface, and an opening extending from the rear surface partially through a thickness of the semiconductor element, the semiconductor element further including a plurality of conductive pads at the front surface, and
a hole extending through at least one of the conductive pads and partially through the thickness of the semiconductor element, the hole meeting the opening at a location between the front and rear surfaces, wherein at the location where the hole and the opening meet, interior surfaces of the hole and the opening extend at different angles relative to the rear surface;
a continuous dielectric layer overlying an interior surface of the at least one conductive pad and overlying an interior surface of the semiconductor material within the hole;
a conductive element electrically contacting the respective at least one conductive pad, the at least one conductive element having a first portion exposed at the rear surface for electrical connection with an external device, the conductive element having a second portion overlying the continuous dielectric layer; and
a mass of material different than the material of the conductive element, the mass contacting and surrounded by the conductive element and the second portion of the conductive element having a second internal space within the hole.
2. The semiconductor assembly as recited in claim 1 ,
wherein the conductive pads have an outwardly facing surface facing away from the semiconductor element,
wherein a portion of the dielectric layer is on the outwardly facing surface of the conductive pads.
3. The semiconductor assembly as recited in claim 1 ,
wherein the conductive element includes a conductive interconnect directly connected to the respective conductive pad and a conductive contact directly connected to the respective conductive interconnect, the conductive contact being exposed at the rear surface.
4. The semiconductor assembly as recited in claim 1 ,
wherein a conductive mass is in contact with the conductive element.
5. The semiconductor assembly as recited in claim 1 ,
wherein the conductive element overlaps the dielectric layer and envelopes the portion of the dielectric layer overlying the conductive pads at the front surface.