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:
Jun. 05, 1984
Filed:
Dec. 31, 1981
Warren D Grobman, Yorktown Heights, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
In electron beam testing systems wherein high energy, high resolution electron beams are used to test lithographic masks, a technique and apparatus are described for discharging electrons which are left on the surface of the mask, and which alter the input trajectory of the electron beam. The materials used in these masks are such that induced photoconductivity and photoemissivity are extremely low and are incapable of providing sufficient electron discharge. A thin, low work function coating is applied over the entire mask surface, the coating being transparent to the radiation which will later be incident upon the mask when it is used in a fabrication process. Due to induced photoemission in the thin coating layer, enough photoemitted electrons will be produced to balance the buildup of electrons from the electron beam, thereby discharging the surface of the mask. The electron beam is a high energy beam, having energies greater than about 5000 eV, and a resolution less than about 1 micrometer.