Interposer capacitor built on silicon wafer and joined to a ceramic substrate

• US 6,791,133 B2
• Filed: 07/19/2002
• Issued: 09/14/2004
• Est. Priority Date: 07/19/2002
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Reddy, Srinivasa, Farooq, Mukta Ghate, Rita, Robert Anthony, Knickerbocker, John U.
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): Nguyen, Dao H.
• Application Number:
  US10/200,479
• Publication Number:
  US 20040014313A1
• Time in Patent Office: 788 Days
• Field of Search: 257/296, 257/306, 257/415, 257/536, 257/691, 257/700, 257/712
• US Class Current: 257/296
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 23/49822 Multilayer substrates multilayer metallisation on monolayer substrate H01L23/498
• CPC Class Codes: H01L 23/49827 Via connections through the substrates, e.g. pins going through the substrate, coaxial cables H01L23/49822, H01L23/49833, H01L23/4985, H01L23/49861 take precedence
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

An interposer, located between an integrated circuit having power, ground and signal connections and a ceramic substrate having power, ground and signal connections, that includes an oxide layer formed on a polished surface of a silicon substrate, a thin film dielectric capacitor formed on the oxide layer, a plurality of metallized that electrically connect to either of the electrodes of the thin film dielectric capacitor, and vias than conduct power, ground and signals between a the ceramic substrate and the integrated circuit. The interposer connects the metallized vias to the integrated circuit by solder connections and also connects the vias conducting power, ground and signals from the ceramic substrate to the interposer by solder connections. The dielectric of the thin film dielectric capacitor may be selected from the group of high-K titanates, such as, barium zirconate titanate, barium strontium titanate, pure barium titanate, barium titanate modified with Pb, Nb, W, Ca, Mg, and Zn, lead titanate, lead zirconate titanate, and polycrystalline lanthanum-modified lead zirconate titanate, or other high-K dielectrics, such as, lead niobate and its derivatives, and lead tungstate and its derivatives.

Claims

1. An interposer located between an integrated circuit having power, ground and signal connections and a ceramic substrate having power, ground and signal connections, the interposer comprising:

an oxide layer formed on a substantially planar surface of a silicon substrate;

a thin film dielectric capacitor, having a first electrode, a dielectric, and a second electrode, formed on the oxide layer;

a plurality of metallized vias including a first metallized via in electrical contact with the first electrode and a second metallized via in electrical contact with the second electrode, the plurality of metallized vias extending from the first electrode and the second electrode to a surface of the interposer, the surface being adjacent to the integrated circuit; and

a plurality of vias including a first via that conducts power between the ceramic substrate and the integrated circuit, a second via that conducts ground between the ceramic substrate and the integrated circuit, and a third via that conducts signals between the ceramic substrate and the integrated circuit.

2. The interposer of claim 1, wherein the substantially planar surface is defined as less than about 500 Å

peak-to-peak of surface irregularity.

3. The interposer of claim 1, further comprising:

a first plurality of solder connections, a first of the first plurality of solder connections electrically connecting the first metallized via in electrical contact with the first electrode and a second of the first plurality of solder connections electrically connecting the second metallized via in electrical contact with the second electrode the integrated circuit.

4. The interpose of claim 3, further comprising:

a second plurality of solder connections including a first connection for electrically connecting the first via that conducts power, a second connection for electrically connecting the second via that conducts ground, and a third connection for electrically connecting the third via that conducts signals, to the ceramic substrate.

5. The interposer of claim 1, wherein the dielectric comprises one of barium zirconate titanate, barium strontium titanate, pure barium titanate, barium titanate modified with Pb, Nb, W, Ca, Mg, and Zn, lead titanate, lead zirconate titanate (PZT), and polycrystalline lanthanum-modified lead zirconate titanate (PLZT).

6. The interposer of claim 1, wherein the dielectric comprises one of lead niobate, lead niobate derivatives, lead tungstate and lead tungstate derivatives.

7. The multilayer ceramic interposer of claim 1, wherein the oxide layer is about 1000 Å

to about 5000 Å

in thickness.

8. The interposer of claim 1, wherein a layer thickness of the dielectric is about 500 Å

to about 3000 Å and

each of the first electrode and the second electrode has a thickness of about 100 Å

to about 5000 Å

.

9. The interposer of claim 1, wherein the first electrode and the second electrode comprise one of platinum, gold, palladium, and silver, and alloys of platinum, gold, palladium, and silver.

10. The interposer of claim 1, wherein at least one of the plurality of metallized vias is electrically connected to at least one of the first via and the second via.

11. A multichip module that includes a decoupling capacitance, comprising:

a ceramic substrate including a power connection, a ground connection, and a signal connection;

an integrated circuit including a power connection a ground connection, and a signal connection,

a multilayer ceramic interposer comprising a thin film dielectric capacitor, which is formed on a substantially planar oxidized silicon surface;

a first plurality of vias in electrical contact with a first electrode and a second electrode of the thin film dielectric capacitor, the first plurality of vias extending from the first electrode and the second electrode to a surface of the multilayer ceramic interposer, the surface being adjacent to the integrated circuit; and

a second plurality of vias comprising;

a power via that conducts power between the power connection of the ceramic substrate and the power connection of the integrated circuit,

a ground via that conducts ground between the ground connection of the ceramic substrate and the ground connection of the integrated circuit, and

a signal via that conducts signals between the signal connection of the ceramic substrate and the signal connection of the integrated circuit.

12. An interposer comprising:

an oxide layer formed on a substantially planar surface of a silicon substrate;

a thin film dielectric capacitor, having a first electrode, a dielectric, and a second electrode, formed on the oxide layer;

a plurality of metallized visa including a first metallized via in electrical contact with the first electrode and a second metallized via in electrical contact with the second electrode, the plurality of metallized visa extending from the first electrode and the second electrode to a surface of the interposer, the surface being adjacent to an integrated circuit,

wherein the dielectric comprises one of barium zirconate titanate, barium strontium titanate, pure barium titanate, barium titanate modified with Pb, Nb, W, Ca, Mg, and Zn, lead titanate, lead zirconate titanate (PZT), polycrystalline lanthanum-modified lead zirconate titanate (PLZT), lead niobate, lead niobate derivatives, lead tungstate and lead tungstate derivatives.

13. The interposer of claim 12, further comprising:

a plurality of visa including a first via that conducts power between a ceramic substrate and the integrated circuit, a second via that conducts ground between the ceramic substrate and the integrated circuit, and a third via that conducts signals between the ceramic substrate and the integrated circuit.

14. The interposer of claim 12, wherein the substantially planar surface is defined as less than about 500 Å

peak-to-peak surface irregularity.

15. An interposer comprising:

an oxide layer formed on a substantially planar surface of a silicon substrate;

a thin film dielectric capacitor, having a first electrode, a dielectric, and a second electrode, formed on the oxide layer;

a plurality of metallized visa including a first metallized via in electrical contact with the first electrode and a second metallized via in electrical contact with the second electrode, the plurality of metallized visa extending from the first electrode and the second electrode to a surface of the interposer, the surface being adjacent to an integrated circuit; and

a plurality of vias including;

at least one of a first via that conducts power between a ceramic substrate and the integrated circuit and a second via that conducts ground between the ceramic substrate and the integrated circuit; and

a third via that conducts signals between the ceramic substrate and the integrated circuit.

16. The interposer of claim 15, wherein the dielectric comprises one of barium zirconate titanate, barium strontium titanate, pure barium titanate, barium titanate modified with Pb, Nb, W, Ca, Mg, and Zn, lead titanate, lead zirconate titanate (PZT), polycrystalline lanthanum-modified lead zirconate titanate (PLZT), lead niobate, lead niobate derivatives, lead tungstate and lead tungstate derivatives.

17. The interposer of claim 15, wherein the substantially planar surface is defined as less than about 500 Å

peak-to-peak of surface irregularity.