Integrated passive device and fabrication method using a last through-substrate via
In one general aspect, an integrated passive device (IPD) die includes at least one passive component that is embedded in an insulator material disposed on a front surface of a substrate. The IPD die includes a through-substrate via (TSV) extending from the backside of the substrate toward the front surface of the substrate. The TSV defines interconnect access to at least one passive component embedded in the insulator material disposed on the front surface of the substrate. The substrate has a thickness less than three-quarters of an original thickness of the substrate.
1. An integrated passive device (IPD) die comprising:
at least one passive device, the passive device having a device body between two device terminals, the device body being embedded in an insulator material disposed on a front surface of an inactive supporting substrate; and
a through-substrate via (TSV) extending from a backside of the substrate through the front surface of the substrate in to an insulator material cavity that exposes a device terminal in the insulator material, the exposed device terminal connected to the device body that is embedded in the insulator material, the TSV defining interconnect access to the at least one passive device having the device body that is embedded in the insulator material disposed on the front surface of the substrate,
the TSV being a tapered TSV having a tapered wall sloping in from a wider surface opening of the TSV to a narrower opening at the front surface of the substrate, the substrate portion of the TSV having a width at the front surface of the substrate wider than a width of the insulator material portion of the TSV at the front surface of the substrate.
2. The IPD die of claim 1 , wherein the device body includes at least one of:
an inductive wire or line structure of an inductor, a resistive material pad of a resistor, or capacitor gap material pad of a capacitor.
3. The IPD die of claim 1 , further comprising, a copper layer disposed on the backside of the substrate, in the TSV along the tapered wall, and in the insulator material cavity, the copper layer defining an electrical connection to the device terminal of the at least one passive device having the device body that is embedded in the insulator material.
4. The IPD die of claim 3 , further comprising:
a solder resist layer; and,
a wafer bump in contact with the copper layer.
5. An integrated passive device (IPD) die, comprising:
at least one passive device, the passive device having a device body between two device terminals, the device body being embedded in insulator material disposed on a front surface of a substrate;
a through-substrate via (TSV) extending from a backside of the substrate toward the front surface of the substrate and extending to a depth in the insulator material disposed on the front surface of the substrate exposing a device terminal connected to the device body that is embedded in the insulator material; and
a copper layer disposed on the backside of the substrate and in the TSV,
the copper layer defining an electrical connection to the exposed device terminal connected to the device body that is embedded in the insulator material through the TSV,
the TSV being a tapered TSV having a tapered wall sloping in from a wider surface opening of the TSV to a narrower opening at the front surface of the substrate, the substrate portion of the TSV having a width at the front surface of the substrate wider than a width of the insulator material portion of the TSV at the front surface of the substrate.
6. The IPD of claim 5 , wherein the IPD die is coupled to a conductive pad, included on a board, using a conductive epoxy or using a wafer bump solder.
7. An integrated passive device (IPD) die, comprising:
a semiconductor substrate having a central portion and an outer portion, the central portion being ground from a backside surface of the substrate to a thickness less than an original thickness of the semiconductor substrate leaving a mechanical support ring on the outer portion of the substrate;
at least one passive device, the passive device having a device body between two device terminals, the device body being at least partially embedded in an insulator material disposed on a front surface of the substrate; and
a through-substrate via (TSV) including a substrate portion etched by a first etch from the backside surface of the substrate to the front surface of the substrate and an insulator material portion etched by a second etch from the front surface of the substrate to a device terminal connected to the device body that is at least partially embedded in the insulator material, the TSV defining interconnect access to the at least one passive device having the device body that is at least partially embedded in the insulator material disposed on the front surface of the semiconductor substrate,
the TSV being a tapered TSV having a tapered wall sloping in from a wider surface opening of the TSV to a narrower opening at the front surface of the substrate, the substrate portion of the TSV having a width at the front surface of the substrate wider than a width of the insulator material portion of the TSV at the front surface of the substrate.
8. The IPD die of claim 7 , wherein the device body that is at least partially embedded in the insulator material includes at least one of an inductor, a resistor, or a capacitor.
9. The IPD die of claim 7 , wherein the central portion is ground to three-quarters or less of the original thickness of the substrate.
10. The IPD die of claim 7 , wherein the mechanical support ring on the outer portion of the substrate is ground to a thickness lower than the original thickness of the substrate.
11. The IPD die of claim 7 , further comprising:
a copper layer plated on the backside surface of the substrate and in the TSV along the tapered wall of the TSV, the plated copper layer defining an electrical connection to a device terminal of the at least one passive device having the device body that is at least partially embedded in the insulator material.
12. The IPD die of claim 11 , wherein the copper layer plated on the backside surface of the substrate and in the TSV along the tapered wall includes a titanium-copper (Ti—Cu) barrier and seed layer deposited on the backside of the substrate and in the TSV along the tapered wall.
13. The IPD die of claim 11 , wherein the copper layer plated on the backside surface of the substrate and in the TSV along the tapered wall includes an oxide layer grown on the backside of the substrate.
14. The IPD die of claim 11 , wherein the copper layer plated on the backside surface of the substrate and in the TSV along the tapered wall is an under bump metal (UBM) etched copper layer.
15. An integrated passive device (IPD) die package, comprising:
a board having a conductive pad thereon; and
an IPD die coupled to the conductive pad, the IPD die including:
at least one passive device, the passive device having a device body between two device terminals, the device body and at least one of the two device terminals being embedded in insulator material disposed on a front surface of a semiconductor substrate;
a through-substrate via (TSV) extending from a backside surface of the semiconductor substrate toward the front surface of the semiconductor substrate and extending to a depth in the insulator material disposed on the front surface of the substrate exposing the at least one of the two device terminals connected to the device body that is embedded in the insulator material; and
a copper layer disposed on the backside surface of the semiconductor substrate and in the TSV,
the copper layer defining electrical connection from the conductive pad on the board to at least one of the two device terminals connected to the device body that is embedded in the insulator material through the TSV,
the TSV being a tapered TSV having a tapered wall sloping in from a wider surface opening of the TSV to a narrower opening at the front surface of the substrate, the substrate portion of the TSV having a width at the front surface of the substrate wider than a width of the insulator material portion of the TSV at the front surface of the substrate.
16. The IPD die package of claim 15 , wherein the IPD die is coupled to the conductive pad using a conductive epoxy or using a wafer bump solder.
17. The IPD die package of claim 15 , wherein the insulator material portion of the TSV extends to a depth of at least 5 μm in the insulator material from the front surface of the substrate to expose the at least one of the two device terminals connected to the device body that is embedded in the insulator material.
18. The IPD die of claim 1 , wherein the insulator material cavity extends to a depth of at least 5 μm in the insulator material from the front surface of the substrate to expose the at least one of the two device terminals connected to the device body that is at least partially embedded in the insulator material.