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:
Mar. 07, 2000
Filed:
Mar. 23, 1998
Hiroshi Nozue, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
There is provided a method of aligning a semiconductor substrate with a base stage on which the semiconductor substrate is placed, in the process of forming a circuit pattern directly onto the semiconductor substrate with electron beams, the method including the steps of (a) scanning across an alignment mark formed on a surface of the semiconductor substrate with electron beams with a scanning angle, defined as an angle between a direction of the electron beams and a reference direction, being varied, (b) calculating a width of the alignment mark along a scanning direction for each of scanning angles, and (c) determining a minimum width among widths calculated in the step (b), and defining a scanning angle associated with the minimum width as an angular gap between the semiconductor substrate and the base stage. In accordance with the above-mentioned method, it is possible to align a semiconductor substrate with an X-Y stage with the less number of movements of the X-Y stage, which ensures a higher efficiency in exposing a semiconductor substrate to electron beams.