A Study of Reticle CD Behavior for Inter-area Pattern Loading Difference

摘要

Many variables arise during a mask manufacturing process has measured its quality index by different equipment and set the spec for the management on it, then proceed an improvement when occurrence of malfunction. However in case of designed wafer products for less 2Xnm, it shows its quality data problems may occur that do not represent the wafer. In case of BL(Bit-Line) pattern that has ranged different patterns density on Mask, Notching and Bridge failure occurs as well as the enhancement through layout modification has the limited further improvement moving within a fixed Pitch scope, there is no substitution for securing a process margin by DB(DateBase) change. So as to find a solution on this Mask production problem, it was proceeded to confirming the cd suitability on each Mask in a stock (manufactured but already disuse processed), these Masks were observed some tendencies of the MTT(Mean to Target) movement along with the cd change. We will introduce the result of mask cd behavior difference depend on pattern loading and present method for mass production of secure mask set.