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:
Apr. 28, 2009
Filed:
May. 30, 2006
Dieter Rathei, Graz, AT;
Dieter Rathei, Graz, AT;
Other;
Abstract
A method of monitoring trends in semiconductor processes is provided. Lot values are assigned to each of a set of wafer lots prior to performing semiconductor processes. After at least some of the semiconductor processes, at least some of the wafer lots are tested to generate a set of test data. A degree of scrambling is calculated for the set of wafer lots already tested using the test data: calculating a current scrambling value by subtracting the lot value of a current wafer lot from a maximum lot value of the lot values assigned for the set of wafer lots to yield the current scrambling value; storing the current scrambling value into a set of scrambling values; and determining a current adjusted maximum scrambling value by multiplying a selected multiplier value with a current maximum scrambling value of the set of scrambling values for a selected number of wafer lots.