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:
Nov. 10, 1998
Filed:
Apr. 22, 1996
Andre Stolmeijer, Santa Clara, CA (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
The present invention provides a method for fabricating small structures to be employed in integrated circuits formed on a semiconductor substrate. Examples of such small structures include contacts, vias, and metal lines. The method of the present invention employs an image reversal technique to obtain improved feature definition. In forming a feature in a layer of material, a clear field reticle is used to form patterned segments of photoresist each having a size, a shape, and a location substantially identical to the size, the shape, and the location of one of the features intended to be formed in the layer of material. This method is employed instead of using a dark field reticle which forms windows in a photoresist each having a size, a shape, and a location substantially identical to the size, the shape, and the location of one of the features intended to be formed in the layer of material. For small structures, the openings or windows in a photoresist are harder to form than the patterned segments of photoresist. With the method of the present invention which employs a clear field reticle to form a mask comprising patterned segments of photoresist, the limitations of patterning small windows in a photoresist with the use of a dark field reticle are avoided. The accuracy of forming the small structures is thus improved.