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:
Oct. 05, 1993
Filed:
Oct. 09, 1992
Akihiko Osawa, Tokyo, JP;
Yoshiro Baba, Yokohama, JP;
Mitsuhiko Kitagawa, Tokyo, JP;
Tetsujiro Tsunoda, Fujisawa, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A mixture of at least two types of charged particles of ions having the same value obtained by dividing the electric charge of an ion by the mass of the ion, i.e., a mixture of charged particles including hydrogen molecular ions H.sub.2.sup.+ and deuterium ions D.sup.+, is accelerated in a charged particle accelerator. Since the mass spectrograph unit in the accelerator cannot divide the hydrogen molecular ions H.sub.2.sup.+ and the deuterium ion D.sup.+, both ions are accelerated together. When the hydrogen molecular ion H.sub.2.sup.+ collides against a silicon substrate, it is divided into two hydrogen ions 2H.sup.+. Since the hydrogen ion H.sup.+ and the deuterium ion D.sup.+ have different ranges in silicon, two regions including a great number of crystal defects are formed in the silicon substrate in one ion irradiating step. As a result, at least three regions of different lifetimes of carriers are formed at different depths of the semiconductor substrate.