Method of manufacturing an on-chip transformer balun

• US 7,171,739 B2
• Filed: 12/04/2003
• Issued: 02/06/2007
• Est. Priority Date: 01/23/2002
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rofougaran, Reza, Yang, Hung Yu (David), Castaneda, Jesse A.
• Primary Examiner(s): TRINH, MINH N
• Application Number:
  US10/727,378
• Publication Number:
  US 20040111881A1
• Time in Patent Office: 1,160 Days
• Field of Search: 296/021, 296/00, 29825-835, 298/46, 298/52, 438/210, 438/238, 438/381, 216/32, 216/39, 336/200, 336/232
• US Class Current: 29/602.1
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 19/04 Transformers or mutual inductances suitable for handling frequencies considerably beyond the audio range resonant circuits H03H
• CPC Class Codes: H01F 2021/125 Printed variable inductor with taps, e.g. for VCO
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• 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: H03H 7/42 Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49135 and shaping, e.g., cutting or bending, etc.

Abstract

A method of manufacturing an on-chip transformer balun includes creating, on a semiconductor substrate, a primary winding having at least one substantially symmetrical primary turn on a first dielectric layer and at least one metal bridge on a second layer. A secondary winding is created on the semiconductor substrate, the secondary winding having at least one substantially symmetrical secondary turn on a third dielectric layer and at least one metal bridge on a fourth dielectric layer. In an alternative embodiment, the primary winding has at least one first primary turn on a first dielectric layer and at least one second primary turn on a second dielectric layer and at least one via that operably connects the first primary turn to the second primary turn. The secondary winding has at least one first secondary turn on a third dielectric layer and at least one second secondary turn on a fourth dielectric layer.

Claims

1. A method of manufacturing an on-chip transformer balun, the method comprises:

creating, on a substrate, a primary winding having at least one primary turn on a first dielectric layer and at least one metal bridge on a second dielectric layer, wherein the at least one primary turn is substantially symmetrical; and

creating, on the semiconductor substrate, a secondary winding having at least one secondary turn on a third dielectric layer and at least one metal bridge on a fourth dielectric layer, wherein the at least one secondary turn is substantially symmetrical, and wherein the secondary winding is magnetically coupled to the primary winding.

2. The method of claim 1, wherein the creating of the primary winding further comprises:

creating a plurality of turns on a first dielectric layer;

creating a plurality of metal bridges on the second dielectric layer; and

operably connecting the plurality of metal bridges to the plurality of turns to provide the primary winding.

3. The method of claim 1, wherein the creating of the secondary winding further comprises:

creating a plurality of turns on the third dielectric layer;

creating a plurality of metal bridges on the fourth dielectric layer; and

operably connecting the plurality of metal bridges to the plurality of turns to provide the secondary winding.

4. The method of claim 1 further comprises:

creating the primary winding to include an interwoven spiral-type primary inductor; and

creating the secondary winding to include an interwoven spiral-type secondary inductor that is substantially symmetrical to the primary winding.

5. The method of claim 1 wherein the primary winding includes an interwoven spiral-type primary inductor including a first number of multiple turns;

and

wherein the secondary winding includes an interwoven spiral-type secondary inductor including a second number of multiple turns.

6. The method of claim 1, wherein the creating of the secondary winding further comprises:

connecting a center tap of the secondary winding to ground to provide a differential signal at end ports of the secondary winding.