# US 11,443,879 B2 · Magnetic core for integrated magnetic devices

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- Number: US 11,443,879 B2
- Document ID: US11443879B2
- Status: Granted
- Kind: B2
- Application number: 16/512,642
- Filed: 2019-07-16
- Published: 2019-11-07
- Granted: 2022-09-13
- Earliest claimed: 2017-06-09
- Assignees: Texas Instruments Incorporated
- Applicants: Texas Instruments Incorporated
- Inventors: Fuchao Wang; Yousong Zhang; Neal Thomas Murphy; Brian Zinn; Jonathan P. Davis
- Web page: https://patentgrep.com/patent/US11443879B2

## CPC

- H01F 10/30: characterised by the composition of the intermediate layers {, e.g. seed, buffer, template, diffusion preventing, cap layers (H01F10/06 and H01F10/32 take precedence)}
- H01F 17/0033: {with the coil helically wound around a magnetic core}
- H01F 27/24: Magnetic cores
- H01F 41/046: {structurally combined with ferromagnetic material}
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES

## Abstract

An integrated magnetic device has a magnetic core which includes layers of the magnetic material located in a trench in a dielectric layer. The magnetic material layers are flat and parallel to a bottom of the trench, and do not extend upward along sides of the trench. The integrated magnetic device is formed by forming layers of the magnetic material over the dielectric layer and extending into the trench. A protective layer is formed over the magnetic material layers. The magnetic material layers are removed from over the dielectric layer, leaving the magnetic material layers and a portion of the protective layer in the trench. The magnetic material layers along sides of the trench are subsequently removed. The magnetic material layers along the bottom of the trench provide the magnetic core.

## Claims

### Claim 1

An integrated magnetic device, comprising:
a substrate;
a trench structure adjacent to the substrate;
a magnetic core in the trench structure, the magnetic core having a top surface and a bottom surface between the top surface and the substrate, the bottom surface wider than the top surface;
an upper dielectric layer disposed over the magnetic core; and
a core dielectric layer over the substrate, the trench substrate being located in the core dielectric layer, the trench structure having sides and a bottom.

### Claim 2 (depends on 1)

The integrated magnetic device of claim 1, wherein:
the magnetic core includes magnetic material layers that are flat and parallel to a bottom of the trench structure; and
the magnetic material layers include a metal selected from the group consisting of iron, nickel, and cobalt.

### Claim 3 (depends on 2)

The integrated magnetic device of claim 2, wherein the magnetic core includes barrier layers alternating with the magnetic material layers.

### Claim 4 (depends on 1)

The integrated magnetic device of claim 1, further comprising a lower encapsulation layer in the trench structure under the magnetic core.

### Claim 5 (depends on 4)

The integrated magnetic device of claim 4, wherein the lower encapsulation layer includes a material selected from the group consisting of titanium, titanium nitride, tantalum, and tantalum nitride.

### Claim 6 (depends on 1)

The integrated magnetic device of claim 1, further comprising an upper encapsulation layer in the trench structure over the magnetic core.

### Claim 7 (depends on 6)

The integrated magnetic device of claim 6, wherein the upper encapsulation layer includes a material selected from the group consisting of titanium, titanium nitride, tantalum, tantalum nitride, and palladium.

### Claim 8 (depends on 1)

The integrated magnetic device of claim 1, wherein:
the trench structure is a first trench structure, and further comprising a second trench structure adjacent to the substrate; and
the magnetic core is also located in the second trench structure, below an opening of the second trench structure.

### Claim 9

An electromagnetic device, comprising:
an opening within a core dielectric layer of a first dielectric material, the core dielectric layer having a top surface and side surfaces within the opening; and
a magnetic core within the opening, the magnetic core having a core top surface located below the dielectric layer top surface and having a first width, and sloped sidewalls that slope from the top surface towards the side surfaces to a bottom core surface located between the top surface and a device substrate and having a second width greater than the first width,
wherein the magnetic core layer includes magnetic material layers, adjacent ones of the magnetic material layers being separated by a barrier layer.

### Claim 10 (depends on 9)

The device of claim 9, further comprising a protective coating over the side surfaces, the top surface of the magnetic core layer, and the sloped sidewalls of the magnetic core layer.

### Claim 11 (depends on 9)

The device of claim 9, further comprising a layer of trench fill material within the opening and over the magnetic core layer.

### Claim 12 (depends on 9)

The device of claim 9, further comprising a dielectric layer of a second different dielectric material that touches the core dielectric layer within the opening, an encapsulation layer over the magnetic core layer, and a fill material within the opening.

### Claim 13 (depends on 12)

The device of claim 12, further comprising a barrier lined located between the core dielectric layer and the magnetic core layer, wherein the barrier liner covers the sidewalls and underlies the magnetic core layer.

### Claim 14 (depends on 13)

The device of claim 13, further comprising a dielectric layer of a second different dielectric material that touches the core dielectric layer within the opening, the barrier liner, an encapsulation layer over the magnetic core layer, and a fill material within the opening.

### Claim 15 (depends on 9)

The device of claim 9, wherein the magnetic core layer has a trapezoidal section profile.

### Claim 16

An integrated magnetic device, comprising:
a substrate;
a first trench structure and a second trench structure adjacent to the substrate, the first trench structure adjacent the second trench structure;
a magnetic core having a first magnetic core portion in the first trench structure and a second magnetic core portion in the second trench structure, each magnetic core portion having a top surface and a wider bottom surface; and
an upper dielectric layer disposed over the magnetic core.

### Claim 17 (depends on 16)

The integrated magnetic device of claim 16, wherein the substrate comprises a semiconductor material.

### Claim 18

An integrated magnetic device, comprising:
a substrate;
a trench structure adjacent to the substrate;
a magnetic core in the trench structure, the magnetic core having a top surface and a bottom surface between the top surface and the substrate, the bottom surface wider than the top surface;
an upper dielectric layer disposed over the magnetic core,
wherein the magnetic core includes magnetic material layers that are flat and parallel to a bottom of the trench structure; and
the magnetic material layers includes a metal selected from the group consisting of iron, nickel, and cobalt.

### Claim 19

An integrated magnetic device, comprising:
a substrate;
a trench structure adjacent to the substrate;
a magnetic core in the trench structure, the magnetic core having a top surface and a bottom surface between the top surface and the substrate, the bottom surface wider than the top surface;
an upper dielectric layer disposed over the magnetic core; and
a lower encapsulation layer in the trench structure under the magnetic core.

### Claim 20

An integrated magnetic device, comprising:
a substrate;
a trench structure adjacent to the substrate;
a magnetic core in the trench structure, the magnetic core having a top surface and a bottom surface between the top surface and the substrate, the bottom surface wider than the top surface;
an upper dielectric layer disposed over the magnetic core; and
an upper encapsulation layer in the trench structure over the magnetic core.

### Claim 21

An integrated magnetic device, comprising:
a substrate;
a trench structure adjacent to the substrate;
a magnetic core in the trench structure, the magnetic core having a top surface and a bottom surface between the top surface and the substrate, the bottom surface wider than the top surface;
an upper dielectric layer disposed over the magnetic core,
wherein the trench structure is a first trench structure, and further comprising a second trench structure adjacent to the substrate; and
the magnetic core is also located in the second trench structure, below an opening of the second trench structure.

### Claim 22

An electromagnetic device, comprising:
an opening within a core dielectric layer of a first dielectric material, the core dielectric layer having a top surface and side surfaces within the opening; and
a magnetic core within the opening, the magnetic core having a core top surface located below the dielectric layer top surface and having a first width, and sloped sidewalls that slope from the top surface towards the side surfaces to a bottom core surface located between the top surface and a device substrate and having a second width greater than the first width; and
a dielectric layer of a second different dielectric material that touches the core dielectric layer within the opening, an encapsulation layer over the magnetic core layer, and a fill material within the opening.

### Claim 23

An electromagnetic device, comprising:
an opening within a core dielectric layer of a first dielectric material, the core dielectric layer having a top surface and side surfaces within the opening; and
a magnetic core within the opening, the magnetic core having a core top surface located below the dielectric layer top surface and having a first width, and sloped sidewalls that slope from the top surface towards the side surfaces to a bottom core surface located between the top surface and a device substrate and having a second width greater than the first width; and
a barrier line located between the core dielectric layer and the magnetic core layer, wherein the barrier liner covers the sidewalls and underlies the magnetic core layer.