Variable inductor and semiconductor device using same

• US 9,324,778 B2
• Filed: 01/26/2012
• Issued: 04/26/2016
• Est. Priority Date: 03/29/2011
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Sato, Junji, Mizuno, Koichi, Fujita, Suguru
• Primary Examiner(s): Jackson, Jr., Jerome
• Assistant Examiner(s): Jiang, Fang-Xing
• Application Number:
  US13/814,871
• Publication Number:
  US 20130140672A1
• Time in Patent Office: 1,552 Days
• Field of Search: 257528-531, 438/381
• US Class Current: 1/1
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 21/005 Inductances without magnetic core
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 27/0605 integrated circuits made of compound material, e.g. AIIIBV
• 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

A variable inductor includes a spiral inductor, a loop conductor, and a switch for opening or short-circuiting an end of the loop conductor. The loop conductor is formed in a direction perpendicular to the spiral inductor and is used for adjusting the inductance value of the spiral inductor by opening or short-circuiting the end of the loop conductor by the switch.

Claims

1. A variable inductor comprising:

a spiral inductor arranged in a plane on a semiconductor substrate;

a loop conductor including an opening that is arranged in one or more layers which are lower than the plane occupied by the spiral inductor and includes a first layer conductor and a second layer conductor;

a dielectric layer arranged between the loop conductor and the spiral inductor; and

a switch adapted to open or close a loop of the loop conductor, the dielectric layer being arranged between the switch and the spiral inductor;

wherein the first layer conductor and the second layer conductor of the loop conductor define a plane, the plane defined by the first layer conductor and the second layer conductor of the loop conductor is arranged in a direction perpendicular to and beneath the plane occupied by the spiral inductor.

2. The variable inductor according to claim 1, wherein the spiral inductor is formed on one surface of the semiconductor substrate;

and

wherein the

first layer conductor is formed in a layer which is lower than the spiral inductor;

the second layer conductor is formed in a layer which is lower than the first layer conductor; and

the variable inductor further comprises;

a vertical conductor formed in a via which is formed in at least a

part of the semiconductor substrate and in a direction perpendicular to the one surface of the semiconductor substrate, the vertical conductor connecting the first layer conductor to the second layer conductor.

3. The variable inductor according to claim 2, wherein the semiconductor substrate is a silicon substrate;

wherein the spiral inductor is formed from a surface conductor formed on a topmost layer of the silicon substrate;

wherein the first layer conductor is an inner layer conductor positioned at a lower layer side with respect to the surface conductor through an interlayer dielectric film;

wherein the second layer conductor is a backside conductor formed on a back side of the silicon substrate; and

wherein the loop conductor includes;

the inner layer conductor;

the vertical conductor formed in a pass-through via which penetrates through the silicon substrate; and

the backside conductor; and

the switch adapted to open or close a loop of the loop conductor.