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:
Aug. 03, 1999
Filed:
Jan. 31, 1997
Koichi Sawahata, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a computer-implemented simulation method for implanting ions into a semiconductor substrate, a region is defined in a vertical cross-section of the substrate between first and second horizontal lines, the first horizontal line being spaced a distance R.sub.p -N.sigma. from a top surface of the substrate and the second horizontal line being spaced a distance R.sub.p +N.sigma. from the top surface, where R.sub.p is a projected range of implanted ions from the top surface, N is an integer, and .sigma. is a standard deviation of horizontal spread of an impurity profile. An orthogonal coordinate system is then defined by a set of narrowly spaced horizontal parallel lines within the region, a set of widely spaced horizontal parallel lines outside of the region and a set of vertical parallel lines at spacing which increases as a function of distance from opposite vertical edges of the coordinate system. A simulation of ion implantation is performed into the substrate and an impurity profile is obtained using the coordinate system.