Danh T Nguyen

US Patent:

8207748, Jun 26, 2012

Filed:

Aug 10, 2005

Appl. No.:

11/573478

Inventors:

Austin Blew - Lehighton PA, US
Michael W. Bronko - Lehighton PA, US
Steven C. Murphy - Pottsville PA, US
Danh Nguyen - Allentown PA, US
Nikolai Eberhardt - Bethlehem PA, US
Jerome C. Licini - Macungie PA, US
William Zuidervliet - Allentown PA, US

Assignee:

Lehighton Electronics, Inc. - Lehighton PA

International Classification:

G01R 27/04

US Classification:

324637, 356399

Abstract:

An apparatus () for contactless measurement of sheet charge density and mobility includes a microwave source (), a circular waveguide () for transmitting microwave power to a sample (), such as a semiconductor wafer or panel for flat panel displays, at a measurement location, a first detector () for detecting the forward microwave power, a second detector () for detecting the microwave power reflected from the sample, and a third detector () for detecting the Hall effect power. An automatic positioning subsystem () is also provided for allowing automatic positioning of a wafer () within the test apparatus (). The positioning system () includes a first end effector () and a rotator-lifter (). The first end effector () can grasp a sheet element () and move it to a desired position within the test apparatus (), while the rotator lifter () provides incremental adjustment of a theta angle of the sheet element () to allow automated mapping of an entire sheet element without the need for manual adjustment of the position of the sheet element. A second end effector () can be mounted opposite the first end effector () and can be used to automatically position the sheet element () within a sheet resistance testing module () located at an opposite end of the apparatus ().