METHOD TO IMPROVE INDUCTANCE WITH A HIGH-PERMEABILITY SLOTTED PLATE CORE IN AN INTEGRATED CIRCUIT

• US 20090002115A1
• Filed: 09/02/2008
• Published: 01/01/2009
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Brennan, Kenneth D., Williams, Byron, Papa Rao, Satyavolu S.
• Granted Patent: US 7,969,274 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 2017/008 Electric or magnetic shielding of printed inductances
• 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: H01L 2924/3011 Impedance
• CPC Class Codes: Y10T 29/49073 by assembling coil and core

Abstract

An inductor structure (102) formed in an integrated circuit (100) is disclosed, and includes a first isolation layer (106) and a first core plate (104) disposed over or within the first isolation layer (106, 114). The first core plate (104) includes a plurality of electrically coupled conductive traces composed of a conductive ferromagnetic material layer. A second isolation layer (108) overlies the first isolation layer and an inductor coil (102) composed of a conductive material layer (118) is formed within the second isolation layer (108). Another core plate may be formed over the coil. The one or more core plates increase an inductance (L) of the inductor coil (102).

Claims

1. A method of forming an integrated inductor structure over a semiconductor substrate, comprising:

providing a first isolation layer disposed over the semiconductor substrate;

forming trenches within the first isolation layer;

forming a core plate comprising a conductive ferromagnetic material layer disposed within the trenches of the first isolation layer;

forming a second isolation layer over the core plate and the first isolation layer;

forming an inductor coil of a conductive material layer disposed within trenches overlying the second isolation layer and the core plate; and

removing a portion of the inductor coil material and the first core plate material to provide isolation between turns of the inductor coil and to define an electrically continuous core plate with radially spaced apart traces;

wherein the core plate increases an inductance of the inductor coil.

2. The method of claim 1, wherein the core plate of the inductor further comprises a capacitor plate, and wherein the plate of the capacitor is electrically connected to the inductor coil.

3. An inductor structure formed in an integrated circuit, comprising:

a first isolation layer;

a coil-shaped trench formed in the first insulation layer;

a core plate layer comprising a conductive ferromagnetic material residing in the coil-shaped trench;

a conductive layer overlying or underlying the core plate layer in the coil-shaped trench, thereby forming an inductor coil, wherein the core plate layer increases an inductance of the inductor coil.

4. An inductor structure formed in an integrated circuit, comprising:

a first isolation layer;

a coil-shaped trench formed in the first insulation layer;

one or more core plate vias or trenches formed in the first insulation layer and electrically isolated from the coil-shaped trench;

a conductive material residing in the coil-shaped trench and forming an inductor coil therein; and

a conductive ferromagnetic material residing in the one or more core plate vias or trenches, wherein the conductive ferromagnetic material forms one or more core plates that increase an inductance of the inductor coil.