Integrated circuit transformer for radio frequency applications

• US 20040095222A1
• Filed: 11/04/2003
• Published: 05/20/2004
• Est. Priority Date: 06/13/2002
• Status: Active Grant

• Current Assignee: International Business Machines SA (International Business Machines Corporation)
• Original Assignee: International Business Machines SA (International Business Machines Corporation)
• Inventors: Wang, Xiaodong, Liang, Tao
• Granted Patent: US 6,959,482 B2
• Time in Patent Office: Days
• US Class Current: 336/223
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 2017/0093 Common mode choke coil
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 41/041 Printed circuit coils apparatus or processes for manufacturing printed circuits in general H05K3/00
• CPC Class Codes: H01L 27/08 including only semiconductor components of a single kind
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

An integrated circuit transformer. A substrate supporting multiple layers of materials of an integrated circuit is provided with a first metallization layer comprising a first set of turns of a primary winding of a transformer, and a second set of turns of a secondary winding of the transformer. A insulation layer is deposited over the first metallization layer, and a second metallization layer bearing a second set of turns of the primary winding, and an optional third set of turns of a second secondary winding. A via connection connects one end of the first set of turns of the primary winding to the second turns of the primary winding located on the second metallization layer. The result is a transformer structure where the primary winding is provided on multiple layers and each secondary winding is confined to a single layer.

Claims

1. An integrated circuit transformer comprising:

a substrate for supporting multiple layers of an integrated circuit;

a first metallization layer comprising a first set of turns of a primary winding of a transformer, and a second set of turns of a first secondary winding of said transformer;

a second metallization layer separated from said first metallization layer by an insulating layer, said second metallization layer comprising a second set of turns of said primary windings and

a via connection connecting one end of said primary first set of turns to one end of said primary winding second turns, whereby a complete primary winding is provided using said first and second metallization layers.

2. The integrated circuit transformer according to claim 1 comprising a third metallization layer for connecting the ends of said windings to external connections of said integrated circuit.

3. The integrated circuit transformer according to claim 1 further comprising a third set of turns of said secondary winding coplanar with, and separated by said second set of turns of said primary winding.

4. A method of manufacturing an integrated circuit transformer comprising:

forming a first metallization layer on a substrate comprising a first plurality of turns of a first winding;

forming an insulating layer over said first metallization layer;

forming a second metallization layer on said insulating layer comprising a second plurality of turns of a second winding, and a third plurality of turns of a third windings; and

connecting one end of said second winding to one end of said first winding whereby a primary winding is provided for said transformer and said third winding comprises a secondary for said transformer.

5. The method according to claim 4 further comprising forming a via in said insulating layer and connecting said one end of said second winding to said one end of said first winding through said via.

6. The method according to claim 4 wherein said second plurality of turns of said second winding are separated by said third plurality of turns of said third winding.

7. The method according to claim 4 further comprising:

forming a fourth set of a plurality of turns of a fourth winding on said first metallization layer to form a second secondary winding for said transformer.

8. The method according to claim 7 wherein each turn of said fourth winding is separated from each other by said first plurality of turns of said transformer winding.

9. The method according to claim 4 further comprising:

forming an insulating layer over a region of a substrate having semiconductor devices; and

forming said first metallization layer on said insulating layer.

10. The method according to claim 9 wherein said insulating layer comprises SiO2.