Michael A Weitzel

US Patent:

7744274, Jun 29, 2010

Filed:

Jun 20, 2007

Appl. No.:

11/820558

Inventors:

Boris Grek - Hayward CA, US
Michael Weitzel - San Jose CA, US
David A. Markle - Saratoga CA, US

Assignee:

Ultratech, Inc. - San Jose CA

International Classification:

G01J 1/00
G01J 1/08

US Classification:

374124, 374167, 374141, 438308

Abstract:

Provided is an apparatus for substrate processing. The apparatus may include a radiation source emitting a photonic beam, an optical system to form a beam image, a scanning stage, a temperature monitoring means, an output signal generator that compares the monitored temperature with a preset temperature, and a controller coupled to the radiation source and the stage. The stage may be adapted to scan the substrate so the beam image heats a region of the substrate surface, and the temperature monitoring means may collect and analyzes p-polarized radiation of at least three different spectral regions emitted from one or more places on the heated substrate region. The controller in response to a temperature error signal may be programmed to alter the beam intensity and/or to provide changes in the scanning velocity between the stage and the beam. Other apparatuses and temperature monitoring systems are provided as well.

US Patent:

20060176917, Aug 10, 2006

Filed:

Feb 9, 2005

Appl. No.:

11/054052

Inventors:

Boris Grek - Hayward CA, US
Michael Weitzel - San Jose CA, US
Igor Landau - Palo Alto CA, US

Assignee:

Ultratech, Inc. - San Jose CA

International Classification:

H01S 3/13

US Classification:

372029020

Abstract:

Systems and methods for stabilizing a COlaser are disclosed. The system includes a detector unit for measuring the power in a select portion of the output beam. The detector unit generates an electrical signal corresponding to the measured power. The modulation frequency of the signal used to modulate the relatively high-frequency radio-frequency (RF) pump signal is filtered from the electrical signal. The filtered electrical signal is then compared to a desired value for the output power in the output beam. Based on the comparison, a modulation control signal for modulating the RF pump signal is formed. The modulation control signal has a varying duty cycle that varies the amount of laser pump power to reduce or eliminate the measured variations in the output beam power. The result is an output beam power that remains stable over time.

US Patent:

20080023452, Jan 31, 2008

Filed:

Sep 27, 2007

Appl. No.:

11/904727

Inventors:

Boris Grek - Hayward CA, US
Michael Weitzel - San Jose CA, US
Igor Landau - Palo Alto CA, US

International Classification:

B23K 26/00
H01S 3/13

US Classification:

219121620, 219121610, 372029021

Abstract:

Systems and methods for stabilizing a COlaser are disclosed. The system includes a detector unit for measuring the power in a select portion of the output beam. The detector unit generates an electrical signal corresponding to the measured power. The modulation frequency of the signal used to modulate the relatively high-frequency radio-frequency (RF) pump signal is filtered from the electrical signal. The filtered electrical signal is then-compared to a desired value for the output power in the output beam. Based on the comparison, a modulation control signal for modulating the RF pump signal is formed. The modulation control signal has a varying duty cycle that varies the amount of laser pump power to reduce or eliminate the measured variations in the output beam power. The result is an output beam power that remains stable over time.

US Patent:

20220362585, Nov 17, 2022

Filed:

May 28, 2022

Appl. No.:

17/827697

Inventors:

- Palo Alto CA, US
Moussa Najib ISKANDAR - Fremont CA, US
Michael William WEITZEL - San Jose CA, US
Chris McWILLIAMS - Daly City CA, US

Assignee:

VARIAN MEDICAL SYSTEMS, INC. - Palo Alto CA

International Classification:

A61N 5/10
G01D 5/16
G21K 1/04

Abstract:

A multileaf collimator includes a plurality of movable leaves for shaping a radiotherapy beam, wherein each leaf is independently movable in a same linear travel direction. Each leaf includes a linear array of magnets disposed on a measurement surface of the leaf and an array of magnetoresistive sensors that is disposed proximate the measurement surfaces of the leaves.