# US 7,612,428 B2 · Inductor fabricated with dry film resist and cavity and method of fabricating the inductor

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,612,428 B2
- Document ID: US7612428B2
- Status: Granted
- Kind: B2
- Application number: 11/291,894
- Filed: 2005-12-02
- Published: 2006-08-31
- Granted: 2009-11-03
- Earliest claimed: 2004-12-03
- Assignees: Samsung Electronics Co., Ltd.
- Inventors: Hae-seok Park; In-sang Song; Hyung Choi
- Web page: https://patentgrep.com/patent/US7612428B2

## CPC

- H10W 20/497: {Inductive arrangements or effects of, or between, wiring layers}
- H01F 17/0006: {Printed inductances (printed coils for dynamo-electric machines H02K3/26; printed circuits H05K)}
- H01F 41/041: {Printed circuit coils (apparatus or processes for manufacturing printed circuits in general H05K3/00)}
- H10D 84/00: Integrated devices formed in or on semiconductor substrates that comprise only semiconducting layers, e.g. on Si wafers or on GaAs-on-Si wafers
- H10W 10/021: {of air gaps}
- H10W 10/20: Air gaps
- H01F 2017/0046: {with a conductive path having a bridge}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

An inductor fabricated with a dry film resist and a cavity and a method of fabricating the inductor. The cavity can be formed in a substrate to minimize a parasitic capacitance generated by structures of upper electrodes, an insulating layer, and a lower electrode and minimize energy loss caused by an eddy current generated through the substrate. Also, a process of forming and planarizing the cavity can be simplified so as to form the cavity to a sufficient depth. As a result, an inductor having a high quality factor and a high self resonant frequency can be fabricated. Also, a scheme for simply forming and planarizing a cavity is contemplated.

## Claims

### Claim 1

An inductor comprising:
a substrate;
an insulating layer formed on the substrate;
a first upper electrode formed in a spiral shape on the insulating layer;
a second upper electrode formed on the insulating layer;
a cavity formed in an area of the substrate except for portions corresponding to portions of the insulating layer on which one end of the first upper electrode is formed and on which the second upper electrode is formed; and
a lower electrode formed on an area of the substrate and the cavity, wherein the lower electrode electrically connects the one end of the first upper electrode and the second upper electrode.

### Claim 2 (depends on 1)

The inductor of claim 1, wherein the cavity is formed in an area of the substrate opposite to the upper electrodes except a portion in which the at least one viahole is formed.

### Claim 3 (depends on 1)

The inductor of claim 1, wherein the insulating layer is a dry film resist.

### Claim 4 (depends on 3)

The inductor of claim 3, wherein the insulating layer is strengthened using at least one of whole surface exposure and thermal treating.

### Claim 5 (depends on 3)

The inductor of claim 3, wherein the at least one viahole is one of ion beam etched and chemical photolithography etched.

### Claim 6 (depends on 1)

The inductor of claim 1, wherein the upper electrodes are one of deposited and etched metal layer and electro plated.

### Claim 7 (depends on 1)

The inductor of claim 1, wherein the lower electrode is formed using one of a patterning method using a spray coater and a deposition method using a shadow mask.

### Claim 8 (depends on 1)

The inductor of claim 1, wherein the insulating layer covers the cavity.

### Claim 9 (depends on 1)

The inductor of claim 1, further comprising;
a first viahole connecting the one end of the first upper electrode with the lower electrode through the insulating layer; and
a second viahole connecting the second upper electrode with the lower electrode through the insulating layer.

### Claim 10 (depends on 1)

The inductor of claim 1, wherein the first upper electrode is spirally arranged around an axis which is perpendicular to the substrate.