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:
Jan. 29, 2008
Filed:
Apr. 02, 2001
Robert Joseph Ledoux, Harvard, MA (US);
Raymond Paul Boisseau, Waltham, MA (US);
William Philip Nett, Waltham, MA (US);
Robert Joseph Ledoux, Harvard, MA (US);
Raymond Paul Boisseau, Waltham, MA (US);
William Philip Nett, Waltham, MA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
A method and apparatus for controlling ion beam scanning in an ion implanter is disclosed. Before an implant process is commenced, a scan waveform to create a uniform distribution along a magnetic scan axis is determined, using a travelling Faraday detector (). Charge data from the travelling Faraday () is collected into a small, finite number of channels and this is used to create a histogram of collected charge vs. beam crossing time. This is in turn used to correct a target scan velocity to compensate for any dose non-uniformity. The target scan velocity is used as a first input to a fast feedback loop. A second input is obtained by digitizing the output of an inductive pickup in the magnet of the magnetic scanner in the ion implanter. Each input is separately integrated and Fast Fourier Transformed Error coefficients Fare obtained by dividing. Fourier coefficients from the target scan velocity by Fourier coefficients from the inductive pickup signal. These error coefficients are used to control the command waveform to the magnetic scanner in the ion implanter.