Method of forming a saucer-shaped half-loop MEMS inductor with very low resistance

• US 7,676,922 B1
• Filed: 06/19/2007
• Issued: 03/16/2010
• Est. Priority Date: 08/25/2005
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Johnson, Peter, Hopper, Peter J., Hwang, Kyuwoon, Lindorfer, Philipp
• Primary Examiner(s): PHAN, THIEM D
• Application Number:
  US11/820,464
• Time in Patent Office: 1,001 Days
• Field of Search: 298/52, 296/021, 296/04, 298/29, 336/82, 336/174, 336/185, 336/200, 336/208
• US Class Current: 29/852
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• 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
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49069 Data storage inductor or core
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base

Abstract

A micro-electromechanical system (MEMS) inductor is formed in a saucer shape that completely surrounds a magnetic core structure which is formed from a ferromagnetic material. In addition, an array of MEMS inductors can be formed by dividing up the saucer-shaped MEMS inductor into a number of electrically-isolated MEMS inductor wedges.

Claims

1. A method of forming a semiconductor structure on a semiconductor device having a first non-conductive region and a first via, the method comprising:

forming a first conductive plate that lies over and touches the first non-conductive region and the first via, the first conductive plate having a first region and a second region, the first region having a bottom surface and a top surface, the second region having a bottom surface and a top surface;

forming a conductive structure, the conductive structure having a second conductive plate and a side wall, the second conductive plate having a first region that lies directly over the first region of the first conductive plate, and a second region that lies directly over the second region of the first conductive plate, the first region of the second conductive plate having a bottom surface and a top surface, the second region of the second conductive plate having a bottom surface and a top surface, the side wall extending from the bottom surface of the second region of the second conductive plate to the top surface of the second region of the first conductive plate, the first conductive plate being electrically connected to only the first via and the side wall of the conductive structure;

forming a second non-conductive region that touches the second conductive plate; and

forming a second via in the second non-conductive region that lies above and touches the conductive structure, the conductive structure both touching and being electrically connected to only the first conductive plate and the second via.

2. The method of claim 1 wherein the bottom surface of the first region of the first conductive plate touches the first via, and the bottom surface of the second region of the first conductive plate is spaced apart from the first via.

3. The method of claim 2 wherein the second via touches the top surface of the first region of the second conductive plate, and is spaced apart from the top surface of the second region of the second conductive plate.

4. The method of claim 3 wherein the first conductive plate and the second conductive plate lie in substantially parallel planes.

5. The method of claim 4 wherein the bottom surface of the first region of the first conductive plate and the bottom surface of the second region of the first conductive plate lie in a single plane.

6. The method of claim 4 wherein the top surface of the first region of the second conductive plate and the top surface of the second region of the second conductive plate lie in a single plane.

7. The method of claim 4 wherein the second via lies directly over the first via.

8. The method of claim 4 wherein forming the first conductive plate includes:

forming an opening in the first non-conductive region to expose the first via; and

forming the first conductive plate in the opening.

9. The method of claim 8 wherein forming the conductive structure includes:

forming a layer of non-conducting material on the first conductive plate and the first non-conductive region;

forming an opening in the layer of non-conducting material to expose the first conductive plate; and

forming the conductive structure in the opening in the layer of non-conducting material.

10. The method of claim 9 and further comprising removing a portion of the conductive structure to form two or more conductive structures.

11. The method of claim 8 and further comprising removing a portion of the first conductive plate to form two or more first conductive plates.

12. The method of claim 4 wherein the first via touches a center of the first conductive plate, and the second via touches a center of the second conductive plate.

13. The method of claim 4 wherein the first via lies adjacent to an edge of the first conductive plate, and the second via lies adjacent to an edge of the second conductive plate.

14. The method of claim 4 and further comprising forming a magnetic core structure that lies between and is isolated from the first and second conductive plates.

15. The method of claim 14 wherein forming the first conductive plate includes:

forming an opening in the first non-conductive region to expose the first via; and

forming the first conductive plate in the opening.

16. The method of claim 15 wherein forming the magnetic core structure includes:

forming a layer of non-conducting material on the first conductive plate and the first non-conductive region; and

forming an opening in the layer of non-conducting material so that a portion of the layer of non-conducting material lies between the first conductive plate and a bottom surface of the opening in the layer of non-conducting material.