MINIATURIZED THIN FILM INDUCTORS FOR USE IN INTEGRATED CIRCUITS

• US 3,614,554 A
• Filed: 10/24/1968
• Issued: 10/19/1971
• Est. Priority Date: 10/24/1968
• Status: Expired due to Term

• Current Assignee: Richard Shield, Thomas H. Ramsey
• Original Assignee: Richard Shield, Thomas H. Ramsey
• Inventors: Shield, Richard, Ramsey, Thomas H.
• Primary Examiner(s): Huckert, John W.
• Assistant Examiner(s): Edlow, Martin H.
• Application Number:
  US04/770,375
• Time in Patent Office: 1,090 Days
• Field of Search: 317/235 (22)/ 317/234 (8)/ 317/235 (22.11)/ 317/234 (8.1)/ 336/200
• US Class Current: 257/531
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 2017/0066 with a magnetic layer
• CPC Class Codes: H01F 2017/0086 on semiconductor substrate
• 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

Abstract

Thin film inductors for use with miniaturized integrated circuits are fabricated by forming a first level of parallel metal strips on a substrate and then forming an insulating layer over the strips. A bar of magnetic material is disposed along the center portions of the metal strips and a layer of insulation is deposited over the bar of magnetic material. A second level of parallel metal strips is then formed over the layer of insulation and is connected between opposed ends of adjacent ones of metal strips at the first level to form a continuous flattened coil around the bar of magnetic material. In other embodiments of the invention, the bar of magnetic material may be omitted, or may be disposed outside the continuous flattened coil formed by the metal strips.

Claims

2. The integrated circuit of claim 1 wherein:

a. said first and second conductive members are each spaced to form two groups of conductive members;

wherein b. said first and second groups of said second conductive members respectively overlying said first and second groups of said first conductive members to produce two spaced, miniaturized, thin film inductors electrically connected to said active element.

3. An integrated circuit of the type having active and passive circuit elements formed therein and a miniaturized, thin film inductor formed thereon, comprising in combination:

a. a semiconductor substrate having at least one active circuit element formed therein;

b. a first layer of insulating material overlying and adhering to one major surface of said substrate;

c. a first plurality of selectively spaced, thin film conductive members overlying and adhering to said first insulating layer;

d. a conductive contact terminal electrically connected to one end of one of said first conductive members, said contact terminal being selectively connected to said active and passive elements through an opening selectively overlying said active and passive elements;

e. A second plurality of selectively spaced, thin film conductive members overlying and adhering to said first insulating layer, each of said second conductive members has one end that overlies one end of one of said first conductive members and is connected thereto, and has its other end overlying one end of another of said first conductive members that is adjacent said one conductive member and is connected thereto;

f. a second layer of insulating material overlying and adhering to said first and second conductive members and to the exposed areas of said first insulating layer; and

g. a thin film magnetic member overlying and adhering to said second insulating layer, said magnetic member being spaced within the area defined by the ends of said first conductive members;

h. a conductor pad overlying and electrically connected to one end of said inductor;

wherein i. said first and second conductive members are connected together to form said miniaturized, thin film inductor, said inductor being selectively connected to said active and passive elements by said contact terminal.

4. The inductor of claim 1 wherein said conductive strips are constructed from aluminum.

5. The inductor of claim 1 wherein said magnetic material comprises a nickel-iron alloy.

6. The inductor of claim 1 wherein said conductive strips are constructed from tungsten.

7. The inductor of claim 1 wherein said conductive strips are constructed from gold.

8. The inductor of claim 1 wherein said magnetic material cOmprises a ferrite material.

9. The inductor of claim 1 wherein said magnetic material comprises barium ferrite.