Integrated circuit with oxidation-resistant polymeric layer

• US 6,288,442 B1
• Filed: 09/10/1998
• Issued: 09/11/2001
• Est. Priority Date: 09/10/1998
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Farrar, Paul A.
• Primary Examiner(s): Abraham, Fetsum
• Application Number:
  US09/145,012
• Time in Patent Office: 1,097 Days
• Field of Search: 257/762, 257/751, 257/678, 257/767, 257/773
• US Class Current: 257/678
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76874 for electroless plating
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 23/53228 the principal metal being copper
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53242 the principal metal being a noble metal, e.g. gold
• CPC Class Codes: H01L 23/53252 Additional layers associated with noble-metal layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A typical integrated circuit interconnects millions of microscopic transistors and resistors with aluminum wires buried in silicon-dioxide insulation. Yet, aluminum wires and silicon-dioxide insulation are a less attractive combination than gold, silver, or copper wires combined with polymer-based insulation, which promise both lower electrical resistance and capacitance and thus faster, more efficient circuits. Unfortunately, conventional etch-based techniques are ineffective with gold, silver, or copper, and conventional polymer formation promote reactions with metals that undermine the insulative properties of polymer-based insulations. Accordingly, the inventor devised methods which use a liftoff procedure to avoid etching problems and a non-acid-polymeric precursor and non-oxidizing cure procedure to preserve the insulative properties of the polymeric insulator. The resulting interconnective structures facilitate integrated circuits with better speed and efficiency.

Claims

1. An integrated-circuit assembly comprising:

one or more transistors;

an oxidation-resistant polymeric layer overlying the transistors, wherein the oxidation-resistant polymeric layer comprises a non-acid-based polymeric precursor.

2. The integrated-circuit assembly of claim 1, further comprising:

one or more conductors overlying the polymeric layer and electrically coupled to the one or more transistors.

3. An integrated-circuit assembly comprising:

one or more transistor contact regions;

an oxidation-resistant polymeric layer having one or more openings, with each opening exposing at least a portion of one of the transistor contact regions;

a diffusion-barrier layer having a diffusion-barrier portion within each opening of the oxidation-resistant polymeric layer, with each diffusion-barrier portion covering at least a portion of one or more of the transistor contact regions; and

a copper-, silver-, or gold-based conductive structure having a conductive portion within each opening of the oxidation-resistant polymeric layer, with each conductive portion covering at least a portion of the diffusion-barrier portion within the opening.

4. The integrated-circuit assembly of claim 3, wherein the oxidation-resistant polymeric layer comprises a non-acid-based polymeric precursor.

5. An integrated-circuit assembly comprising:

one or more transistor contact regions;

an oxidation-resistant polymeric layer having one or more openings, with each opening exposing at least a portion of one of the transistor contact regions;

a diffusion-barrier layer having a diffusion-barrier portion within each opening of the oxidation-resistant polymeric layer, with each diffusion-barrier portion covering at least a portion of one or more of the transistor contact regions and having one or more diffusion-barrier sidewalls;

a first copper-, silver-, or gold-based conductive structure having a first conductive portion within each opening of the oxidation-resistant polymeric layer, with each conductive portion covering at least a portion of the diffusion-barrier portion within the opening and having a top surface and one or more conductive sidewalls; and

a second copper-, silver-, or gold-based conductive structure having a second conductive portion within each opening of the oxidation-resistant polymeric layer, with the second conductive portion contacting the top surface and at least one of the conductive sidewalls of the first conductive structure and at least one of the diffusion-barrier sidewalls.

6. The integrated-circuit assembly of claim 5, wherein the oxidation-resistant polymeric layer comprises a non-acid-based polymeric precursor.

7. An integrated-circuit assembly comprising:

one or more transistor contact regions;

an oxidation-resistant polymeric layer having one or more openings, with each opening exposing at least a portion of one of the transistor contact regions;

a diffusion-barrier layer having a diffusion-barrier portion within each opening of the oxidation-resistant polymeric layer, with each diffusion-barrier portion covering at least a portion of one or more of the transistor contact regions; and

a copper-based conductive structure having a conductive portion within each opening of the oxidation-resistant polymeric layer, with each conductive portion covering at least a portion of the diffusion-barrier portion within the opening.

8. The integrated-circuit assembly of claim 7, wherein the oxidation-resistant polymeric layer comprises a non-acid-based polymeric precursor.

9. An integrated-circuit assembly comprising:

one or more transistor contact regions;

an oxidation-resistant polymeric layer having one or more openings, with each opening exposing at least a portion of one of the transistor contact regions;

a diffusion-barrier layer having a diffusion-barrier portion within each opening of the oxidation-resistant polymeric layer, with each diffusion-barrier portion covering at least a portion of one or more of the transistor contact regions; and

a silver- or gold-based conductive structure having a conductive portion within each opening of the oxidation-resistant polymeric layer, with each conductive portion covering at least a portion of the diffusion-barrier portion within the opening.

10. The integrated-circuit assembly of claim 9, wherein the oxidation-resistant polymeric layer comprises a non-acid-based polymeric precursor.

11. An integrated-circuit assembly comprising:

one or more transistor contact regions;

an oxidation-resistant polymeric layer having one or more openings, with each opening exposing at least a portion of one of the t or contact regions;

a diffusion-barrier layer having a diffusion-barrier portion within each opening of the oxidation-resistant polymeric layer, with each diffusion-barrier portion covering at least a portion of one or more of the transistor contact regions and having one or more diffusion-barrier sidewalls;

a first copper-based conductive stricture having a first conductive portion within each opening of the oxidation-resistant polymeric layer, with each conductive portion covering at least a portion of the diffusion-barrier portion within the opening and having a top surface and one or more conductive sidewalls; and

a second copper-based conductive having a second conductive portion within each opening of the oxidation-resistant polymeric layer, with the second conductive portion contacting the top surface and at least one of the conductive sidewalls of the first conductive structure and at least one of the diffusion-barrier sidewalls.

12. The integrated-circuit assembly of claim 11, wherein the oxidation-resistant polymeric layer comprises a non-acid-based polymeric precursor.

13. An integrated-circuit assembly comprising:

one or more transistor contact regions;

an oxidation-resistant polymeric layer having one or more openings, with each opening exposing at least a portion of one of the transistor contact regions;

a diffusion-barrier layer having a diffusion-barrier portion within each opening of the oxidation-resistant polymeric layer, with each diffusion-barrier portion covering at least a portion of one or more of the transistor contact regions and having one or more diffusion-barrier sidewalls;

a first silver- or gold-based conductive structure having a first conductive portion within each opening of the oxidation-resistant polymeric layer, with each conductive portion covering at least a portion of the diffusion-barrier portion within the opening and having a top surface and one or more conductive sidewalls; and

a second silver- or gold-based conductive structure having a second conductive portion within each opening of the oxidation-resistant polymeric layer, with the second conductive portion contacting the top surface and at least one of the conductive sidewalls of the first conductive structure and at least one of the diffusion-barrier sidewalls.

14. The integrated-circuit assembly of claim 13, wherein the oxidation-resistant polymeric layer comprises a non-acid-based polymeric precursor.