The present application relates to a semiconductor structure and a method of forming the same. More particularly, the present application relates to a three-dimensional (3D) bonded semiconductor structure having an embedded capacitor that has a low resistivity and thus exhibits an improved quality factor, Q. The present application also relates to a method of forming such a 3D bonded semiconductor structure.
Three-dimensional (3D) integration is critical in current and in future technology development. Traditionally, oxide-oxide bonding is performed to physically connect two wafers and, thereafter, through-silicon-vias (TSVs) are formed to electrically connect the two wafers.
In the most advanced 3D integration technology development, oxide-oxide and metal to metal (e.g., Cu—Cu) bonding are performed simultaneously. Accordingly, both oxide/oxide bonding strength and metal/metal contact are critical in order to meet the mechanical integrity requirement as well as the electrical performance.
The quality factor, Q, of a capacitor represents the efficiency of a given capacitor in terms of energy losses. The quality factor, Q, decreases with increasing electrical resistance of this device element. Presently, capacitors that are embedded in a 3D semiconductor structure have high resistivity. As such, there is a need for providing a 3D semiconductor structure having an embedded capacitor that has low resistivity and thus, an improved quality factor, Q.