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. 24, 1991
Filed:
May. 26, 1989
George K Celler, New Providence, NJ (US);
Lee E Trimble, Hillsborough, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A mask for X-ray lithography is produced by initially forming a thin layer of polycrystalline silicon on a silicon oxide containing substrate. A portion of the substrate at the periphery of the major surface opposite the silicon layer is masked. The exposed portion of the substrate is removed by an etchant that is selective for silicon oxide containing composition relative to silicon, e.g. aqueous HF. The resulting membrane of silicon on a peripheral region of silicon oxide containing compositions is in tensile stress as required for lithography, but is robust. Metal, X-ray absorbing patterns are formed on the silicon by standard lithographic procedures.