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. 26, 1999
Filed:
Feb. 21, 1997
Takayuki Abe, Kawasaki, JP;
Susumu Oogi, Kawasaki, JP;
Takashi Kamikubo, Tokyo, JP;
Hirohito Anze, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A charged particle beam writing method for determining an optimal exposure dose for each position in a pattern to be drawn on a target before actually drawing the pattern by irradiating the target with charged particles and drawing the pattern with the obtained optimal exposure doses, comprising the first step of determining the first approximate optimal exposure dose for each position on said target, the second step of determining the second optimal exposure dose for each position on said target by determining a corrective value di for correcting said first approximate optimal exposure dose obtained by multiplying the error in the exposure dose of the position produced when exposed to said first approximate optimal exposure dose by a regulation coefficient of a value substantially equal to the exposure dose U(x, y) to back scattering charged particles and adding said corrective value to said first approximate optimal exposure dose, said exposure dose being variable as a function of the location (x, y) of the position, the third step of repeating one of (1) the second step for a predetermined number of times, (2) the second step until each of said second approximate optimal exposure doses tends to converge, and (3) the second step until all the errors in said second approximate optimal exposure doses are found within a predetermined value.