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:
May. 05, 1998
Filed:
Aug. 23, 1995
Hiu F Ip, San Jose, CA (US);
Ellick L Ma, San Jose, CA (US);
Micrel, Incorporated, San Jose, CA (US);
Abstract
A structure and method are disclosed which allow for a more efficient use of silicon in a wafer fabrication process. In accordance with the present invention, the layout of masks used in the fabrication of circuit dice is modified by re-configuring the operating protocol of the stepper such that the alignment keys and targets are formed in the two subfields lying in the upper-left and upper-right corners, respectively, of each field. Thus, the 200 .mu.m-wide portion of each field previously used for alignment (i.e., alignment scribe line 34 of FIG. 2) may now contain patterns used in the formation of circuit dice, thereby increasing the amount of usable surface area on the associated underlying wafer. The operating protocol is further modified such that scribe lines separating rows and columns of subfields are less than 100 .mu.m wide, thereby resulting in a further reduction in the unused or wasted portions of the silicon wafer, particularly in applications having a large number of small die formed on the wafer.