David R Chapman

US Patent:

7861200, Dec 28, 2010

Filed:

Mar 24, 2008

Appl. No.:

12/054015

Inventors:

Yifeng Yang - Chandler AZ, US
Yun Zhang - Gilbert AZ, US
Yibin Xia - Gilbert AZ, US
David J. Chapman - Mesa AZ, US

Assignee:

Freescale Semiconductor, Inc. - Austin TX

International Classification:

G06F 17/50

US Classification:

716 6, 716 1, 716 4, 716 5, 716 8, 703 13, 703 14, 703 15

Abstract:

A method of characterizing a device under test (DUT) includes determining a goal function associated with a setup and hold time for the DUT. A minimum value for the goal function is determined by iteratively adjusting setup and hold times for input data to the DUT, and determining whether the DUT performs according to specifications. The minimum goal function value will reflect minimum setup and hold time values based on weights associated with the goal function. This allows the minimum setup and hold times for the DUT to be characterized with a small number of binary searches, improving the speed of the characterization process.

US Patent:

20070006801, Jan 11, 2007

Filed:

Jul 6, 2006

Appl. No.:

11/428940

Inventors:

Gerald Stringfellow - Salt Lake City UT, US
Alexander Howard - Salt Lake City UT, US
David Chapman - Stow MA, US

International Classification:

C30B 23/00
C30B 25/00
C30B 28/12
C30B 28/14

US Classification:

117104000

Abstract:

The use of surfactants that do not themselves act as dopants and are isoelectronic with either the group III or group V host atoms during OMVPE growth significantly reduces the incorporation of background impurities such as carbon, oxygen, sulfur and/or silicon. For example, the use of the surfactants Sb or Bi significantly reduces the incorporation of background impurities such as carbon, oxygen, sulfur and/or silicon during the OMVPE growth of III/V semiconductor materials, for example GaAs, GaInP, and GaP layers. As a result, an effective method for controlling the incorporation of impurity atoms is adding a minute amount of surfactant during OMVPE growth.

US Patent:

20110215275, Sep 8, 2011

Filed:

Dec 5, 2007

Appl. No.:

11/951120

Inventors:

Gerald B. Stringfellow - Salt Lake City UT, US
Alexander D. Howard - Salt Lake City UT, US
David C. Chapman - Stow MA, US

Assignee:

The University of Utah Research Foundation - Salt Lake City UT

International Classification:

C09K 11/70
C09K 11/74

US Classification:

2523014P

Abstract:

The use of surfactants that do not themselves act as dopants and are isoelectronic with either the group III or group V host atoms during OMVPE growth significantly reduces the incorporation of background impurities such as carbon, oxygen, sulfur and/or silicon. For example, the use of the surfactants Sb or Bi significantly reduces the incorporation of background impurities such as carbon, oxygen, sulfur and/or silicon during the OMVPE growth of III/V semiconductor materials, for example GaAs, GaInP, and GaP layers. As a result, an effective method for controlling the incorporation of impurity atoms is adding a minute amount of surfactant during OMVPE growth.