Via structure for signal equalization
View Patent ↗An apparatus relating generally to a substrate is disclosed. In such an apparatus, the substrate has a first surface and a second surface opposite the first surface. The first surface and the second surface define a thickness of the substrate. A via structure extends from the first surface of the substrate to the second surface of the substrate. The via structure has a first terminal at or proximate to the first surface and a second terminal at or proximate to the second surface provided by a conductive member of the via structure extending from the first terminal to the second terminal. A barrier layer of the via structure is disposed between at least a portion of the conductive member and the substrate. The barrier layer has a conductivity configured to offset a capacitance between the conductive member and the substrate when a signal is passed through the conductive member of the via structure.
1. An apparatus, comprising:
a substrate having a first surface and a second surface opposite the first surface, the first surface and second surface defining a thickness of the substrate;
a via structure extending from the first surface of the substrate to the second surface of the substrate;
wherein the via structure has a first terminal at or proximate to the first surface and a second terminal at or proximate to the second surface provided by a conductive member of the via structure extending from the first terminal to the second terminal;
wherein a barrier layer of the via structure is disposed between at least a portion of the conductive member and the substrate;
wherein the barrier layer includes a metal and a dielectric material for having a conductivity configured to offset a capacitance between the conductive member and the substrate when a signal is passed through the via structure; and
wherein the barrier layer has a film resistivity equal to or less than approximately 0.5 Ohm-cm to provide a resistance in parallel to the capacitance.
2. The apparatus according to claim 1 , wherein:
the conductive member, the barrier layer, and the substrate in combination provide the capacitance in a range of approximately 50 fF to 2500 fF; and
the via structure does not include a liner layer.
3. The apparatus according to claim 1 , wherein the barrier layer has a thickness in a range of approximately 1 to 50 nm.
4. The apparatus according to claim 1 , wherein a portion of the barrier layer extends away from the conductive member in a horizontal direction to provide a collar.
5. An apparatus, comprising:
a semiconductor substrate having a first surface and a second surface opposite the first surface, the first and second surfaces defining a substrate thickness of the semiconductor substrate;
a via structure extending from the first surface of the semiconductor substrate to the second surface of the semiconductor substrate, the via structure having a first terminal at or proximate to the first surface and a second terminal at or proximate to the second surface and a conductive member extending from the first terminal to the second terminal; and
wherein a barrier layer of the via structure is disposed between at least a portion of the conductive member and the semiconductor substrate;
wherein a liner layer of the via structure is disposed between at least a portion of the barrier layer and the semiconductor substrate;
wherein the barrier layer includes a metal in addition to a first dielectric material in order to provide a resistance in parallel with the parasitic capacitance associated in part with a second dielectric material of the liner layer of the via structure as disposed in the semiconductor substrate;
wherein the barrier layer and the liner layer in combination provide a current conduction path configured to offset an effect of a parasitic capacitance that arises between the conductive member and the semiconductor substrate when a signal is passed through the conductive member of the via structure;
wherein the barrier layer has a film resistivity equal to or less than approximately 0.5 Ohm-cm to provide first parallel resistance to the parasitic capacitance for the resistance; and
wherein the liner layer has a film resistivity equal to or less than approximately 300 Ohm-cm to provide a second parallel resistance to the parasitic capacitance for the resistance.
6. The apparatus according to claim 5 , wherein thickness of the liner layer is in a range of approximately 0.1 to 5 nm to provide an electrical porosity.
7. The apparatus according to claim 5 , wherein the second dielectric material is selected from a group consisting of an organic material and a combination of the inorganic material and the organic material.
8. The apparatus according to claim 5 , wherein the resistance is approximately two orders of magnitude greater than a resistivity of the semiconductor substrate.
9. The apparatus according to claim 5 , wherein the second dielectric material is a silicon-based dielectric material.
10. The apparatus according to claim 9 , wherein the second dielectric material is selected from a group consisting of a silicon oxide, a silicon nitride, a tetra-ethyl ortho-silicate, a phosphor-silicate glass, and a boro-phospho-silicate glass.
11. The apparatus according to claim 10 , wherein the conductive member includes a metal selected from a group consisting of Pt, W, Ni, Al, Au, Ru and Cu.
12. The apparatus according to claim 5 , wherein the liner layer is substantially porous to allow the barrier layer to penetrate into the liner layer.
13. The apparatus according to claim 12 , wherein the barrier layer extends into interstitial gaps in the liner layer to provide a quasi-distributed resistive-capacitive network along an interface between the barrier layer and the liner layer.
14. The apparatus according to claim 12 , wherein the parasitic capacitance of the via structure is in a range of approximately 50 to 2500 fF.