Method for fabricating a inductor of low parasitic resistance and capacitance

• US 6,395,637 B1
• Filed: 10/07/1998
• Issued: 05/28/2002
• Est. Priority Date: 12/03/1997
• Status: Expired due to Term

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Yu, Hyun Kyu, Park, Min, Kim, Cheon Soo
• Primary Examiner(s): Kunemund, Robert
• Assistant Examiner(s): Brown, Charlotte A.
• Application Number:
  US09/168,343
• Time in Patent Office: 1,329 Days
• Field of Search: 438/706,720,745,754,723,724
• US Class Current: 438/706
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 2017/0046 with a conductive path having a bridge
• CPC Class Codes: H01F 27/34 Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
• CPC Class Codes: H01F 41/041 Printed circuit coils apparatus or processes for manufacturing printed circuits in general H05K3/00
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 28/10 Inductors
• 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

The present invention relates to a method for fabricating an inductor and, more particularly, to a method for fabricating a spiral inductor used in a monolithic microwave integrated circuit on a silicon substrate using semiconductor fabrication processes. The method for fabricating an inductor, comprising the steps of: forming a first dielectric layer on a silicon substrate and forming a first metal wire on the first dielectric layer, wherein the first metal wire is in contact with an active element formed on the silicon substrate; and alternatively forming dielectric layers and metal layers, wherein the metal layers are electrically connected with an upper metal wire and a lower metal wire and wherein the metal layers are patterned using the dielectric layers as etching mask, whereby a metal corrosion is prevented by using the spiral dielectric pattern as the etching mask.

Claims

1. A method for fabricating an inductor, comprising the steps of:

forming a first dielectric layer on a silicon substrate and forming a first metal wire on the first dielectric layer, wherein the first metal wire is in contact with an active element formed on the silicon substrate;

forming a second dielectric layer on the resulting structure and forming an opening exposing the first metal wire;

forming a second metal wire which is electrically connected with the first metal wire;

forming a spiral dielectric pattern on the second metal wire; and

etching the second metal wire using the spiral dielectric pattern as an etching mask, thereby forming a spiral metal wire,

whereby a metal corrosion is prevented by using the spiral dielectric pattern as the etching mask.

2. The method in accordance with claim 1, wherein the spiral dielectric pattern is one of a silicon oxide layer, a silicon nitride layer and a silicon oxide/silicon nitride layer.

3. The method in accordance with claim 1, wherein the second dielectric layer has a SiO₂/SOG(spin-on-glass)/SiO₂ structure.

4. The method in accordance with claim 1, wherein a selective etching ratio for the second metal wire to the spiral dielectric pattern is of over 10:

1.

5. The method in accordance with claim 1, wherein the second metal wire comprises a TiN barrier metal layer and an Al metal layer.

6. The method in accordance with claim 5, wherein the method further comprises a step of reflowing the Al metal layer.

7. A method for fabricating an inductor, comprising the steps of:

forming a first dielectric layer on a silicon substrate and forming a first metal wire on the first dielectric layer, wherein the first metal wire is in contact with an active element formed on the silicon substrate;

forming a second dielectric layer on the resulting structure and forming a first opening and recesses exposing the first metal wire;

forming a second metal wire which is electrically connected with the first metal wire;

forming a first spiral dielectric pattern on the second metal wire;

etching the second metal wire using the first spiral dielectric pattern as an etching mask, thereby forming a first spiral metal wire;

forming a third dielectric layer on the resulting structure and patterning the third dielectric layer to expose the second metal wire through a second opening and recesses;

forming a third metal wire which is electrically connected with the second metal wire;

forming a second spiral dielectric pattern on the third metal wire; and

etching the third metal wire using the second spiral dielectric pattern as an etching mask, thereby forming a second spiral metal wire.

8. The method in accordance with claim 7, wherein the method further comprises the steps of:

depositing a dielectric layer on the resulting structure; and

forming a metal wire on the dielectric layer, being electrically connected with the lower metal wire.

9. The method in accordance with claim 7, wherein the first and second spiral dielectric patterns are one of a silicon oxide layer, a silicon nitride layer and a silicon oxide/silicon nitride layer.

10. The method in accordance with claim 7, wherein the method further comprises a step of reflowing the first to third metal wires.

11. A method for fabricating an inductor, comprising the steps of:

forming a first dielectric layer on a silicon substrate and forming a first metal wire on the first dielectric layer, wherein the first metal wire is in contact with an active element formed on the silicon substrate;

forming a second dielectric layer on the resulting structure and forming an opening exposing the first metal wire;

forming a second metal wire which is electrically connected with the first metal wire;

forming a first spiral dielectric pattern on the second metal wire;

etching the second metal wire using the first spiral dielectric pattern as an etching mask, thereby forming a first spiral metal wire;

forming a third dielectric layer on the resulting structure and patterning the third dielectric layer to expose the second metal wire through an opening;

forming a third metal wire which is electrically connected with the second metal wire;

forming a second spiral dielectric pattern on the third metal wire; and

etching the third metal wire using the second spiral dielectric pattern as an etching mask, thereby forming a second spiral metal wire.

12. The method in accordance with claim 11, wherein the method further comprises a step of reflowing the Al metal layer.

13. The method in accordance with claim 11, wherein the first and second spiral dielectric patterns are one of a silicon oxide layer, a silicon nitride layer and a silicon oxide/silicon nitride layer.

14. A method for fabricating an inductor, comprising the steps of:

forming a first dielectric layer on a silicon substrate and forming a first metal wire on the first dielectric layer, wherein the first metal wire is in contact with an active element formed on the silicon substrate; and

alternatively forming dielectric layers and metal layers, wherein the metal layers are electrically connected with an upper metal wire and a lower metal wire and wherein the metal layers are patterned using the dielectric layers as etching mask.