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. 08, 1993
Filed:
Mar. 22, 1991
Applicant:
Inventor:
Donald L White, Lake Parsippany, NJ (US);
Assignee:
AT&T Bell Laboratories, Murray Hill, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03F / ;
U.S. Cl.
CPC ...
430-5 ; 430-4 ; 430311 ;
Abstract
Expedient fabrication of phase masks providing for many values of phase delay for exiting pattern delineating radiation depends upon a two-step procedure. Such masks offer improvement in ultimate device fabrication relative to that offered by prior binary-valued masks. In the first step, which may be carried out coincident with introduction of device feature information, apertures of appropriate size and distribution are produced in the relevant mask layer; in the second step material surrounding such apertures is heated to result in backflow-filling. The consequential layer thinning is such as to introduce the desired local change in phase delay.