The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 27, 2003
Filed:
Apr. 10, 2000
James B. Owens, Jr., San Jose, CA (US);
Somit Talwar, Bonita, CA (US);
Andrew M. Hawryluk, Los Altos Hills, CA (US);
Yun Wang, San Jose, CA (US);
Ultratech Stepper, Inc., San Jose, CA (US);
Abstract
The closed loop embodiment includes a pulsed laser controller to selectively operate a pulsed laser in a lower-power probe mode or a higher power operational mode. In lower-power probe mode, values of e (total radiation energy flooding ICs on a silicon wafer), e (fraction of e specularly reflected), e (fraction of e scattered) and e (fraction of e transmitted through wafer) are obtained. A value for e (fraction of e absorbed wafer) is calculated i.e. e =e −(e +e +e ), and e used by pulsed laser controller with pulsed laser in higher power operational mode to adjust pulsed laser fluence over the duration of a pulse to provide flooding radiation energy sufficient to melt an amorphized silicon surface layer beneath radiation-absorbent material, yet insufficient to melt crystalline silicon or ablate radiation-absorbent material. Open loop embodiment substitutes a separate low-power probe laser for operation in lower-power probe mode.