# US 7,077,943 B2 · Barium titanate film synthesizing process

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

- Number: US 7,077,943 B2
- Document ID: US7077943B2
- Status: Granted
- Kind: B2
- Application number: 10/612,007
- Filed: 2003-07-03
- Published: 2005-01-06
- Granted: 2006-07-18
- Earliest claimed: 2003-07-03
- Assignees: National Chunghsing University
- Inventors: Fu-Hsing Lu; Chu-Tsun Wu
- Web page: https://patentgrep.com/patent/US7077943B2

## CPC

- C23C 14/5853: {Oxidation}
- C23C 14/165: {by cathodic sputtering}
- C25D 11/26: of refractory metals or alloys based thereon
- H05K 1/162: {incorporating printed capacitors}
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS

## Abstract

A new technique to synthesize barium titanate (BaTiO3) on homogeneous substrates (titanium) or heterogeneous substrates (silicon wafers, metal, glass, ceramics, polymers, other metals, etc.) is disclosed to include a first step to deposit a titanium film on a substrate by sputtering, and a second step to synthesize barium titanate film with uniformly dispersed spherical particles on the titanium-coated substrate in a electrolyte containing barium ions by electrochemically anodic oxidation.

## Claims

### Claim 1

A barium titanate film synthesizing process comprising the steps of:
(a) coating a titanium film on the surface of a substrate, said titanium film having a grain size which is in nano-scale; and
(b) synthesizing a barium titanate film on the titanium-coated substrate in an electrolyte containing barium ions by electrochemically anodic oxidation.

### Claim 2 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein said substrate is selected from the group consisting of titanium, glass, ceramics, polymers, and silicon.

### Claim 3 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein said titanium film is deposited on said substrate by sputtering.

### Claim 4 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein said titanium film is deposited on said substrate by evaporation.

### Claim 5 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein said electrolyte is an alkaline solution of Ba(CH3COO)2 and NaOH.

### Claim 6 (depends on 5)

The barium titanate film synthesizing process as claimed in claim 5, wherein the concentration of Ba(CH3COO)2 is within about 0.35–0.5 M; the concentration of NaOH is 2 M.

### Claim 7 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein said electrochemically anodic oxidation is achieved by voltage within 0.4 V˜3 V.

### Claim 8 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein said electrochemically anodic oxidation is achieved by a voltage scan rate within 10 mV/s˜50 mV/s.

### Claim 9 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein said electrochemically anodic oxidation is achieved within 20 seconds to 24 hours.

### Claim 10 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein said electrochemically anodic oxidation is performed at a processing temperature within 30° C.˜90° C.

### Claim 11 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein said electrochemically anodic oxidation is performed at a processing temperature over 50° C.

### Claim 12 (depends on 1)

The barium titanate film synthesizing process as claimed in claim 1, wherein the nano-scale ranges from 1 nm to 100 nm.