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:
Sep. 04, 1984
Filed:
May. 04, 1982
Ichiro Mori, Kodaira, JP;
Kazuyoshi Sugihara, Yokohama, JP;
Toshiaki Shinozaki, Yokohama, JP;
Toru Tojo, Yamato, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
According to the invention an electron beam pattern transfer device with an improved alignment means is provided. A first and a second mark M.sub.1, M.sub.2 for alignment purposes are formed on the surface of the wafer and the wafer holder, respectively. The first mark M.sub.1 is formed on the wafer by conventional lithographic technique and the second mark M.sub.2 consists of a hole or a heavy metal, such as Ta or Ta.sub.2 O.sub.5. A third alignment mark M.sub.3 is provided on the photocathode mask having a position corresponding to M.sub.2 on the wafer holder and spaced a known distance L.sub.2 from an imaginary reference position M.sub.4 on the mask. The first step of the alignment process requires the detection of a relative distance L.sub.1 between the first and second marks M.sub.1, M.sub.2 by conventional detecting means, such as an optical measuring means. In the next step, the relative position of the photocathode mask and the wafer holder is adjusted so that the distance between the marks M.sub.2 and M.sub.3 is made substantially equal to the difference between the distance L.sub.1 and the known distance L.sub. 2.