Chen Gao

US Patent:

6660414, Dec 9, 2003

Filed:

Apr 26, 1999

Appl. No.:

09/299805

Inventors:

Xiao-Dong Xiang - Alameda CA
Hauyee Chang - Berkeley CA
Chen Gao - Berkeley CA
Ichiro Takeuchi - Albany CA
Peter G. Schultz - Oakland CA

Assignee:

U.S. Department of Energy - Washington DC

International Classification:

B32B 900

US Classification:

428697, 428702, 428701, 428699, 428689, 501134, 501135, 501136, 501137, 501139, 1062862, 1062864, 1062866, 1062868, 10628719

Abstract:

A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a composition of tungsten-doped barium strontium titanate of the general formula (Ba Sr )TiO , where X is between about 0. 5 and about 1. Also provided is a method for making a dielectric thin film of the general formula (Ba Sr )TiO and doped with W, where X is between about 0. 5 and about 1. 0, a substrate is provided, TiO , the W dopant, Ba, and optionally Sr are deposited on the substrate, and the substrate containing TiO , the W dopant, Ba, and optionally Sr is heated to form a low loss dielectric thin film.

US Patent:

6173604, Jan 16, 2001

Filed:

Sep 22, 1998

Appl. No.:

9/158037

Inventors:

Xiao-Dong Xiang - Alameda CA
Chen Gao - Alameda CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

G01B 734

US Classification:

73105

Abstract:

A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.