Mask topography effects need to be taken into consideration for a more accurate solution of source mask optimization (SMO) in advanced optical lithography. However, rigorous 3D mask models generally involve intensive computation and conventional SMO fails to manipulate the mask-induced undesired phase errors that degrade the usable depth of focus (uDOF) and process yield. In this work, an optim...

The influence of line-edge roughness (LER) of an optical photomask on the resulting printed wafer LER is investigated. The LER Transfer function (LTF) proposed by Naulleau and Gallatin, and later corrected by Tanabe, is shown to be a very useful tool for evaluating the low-pass filtering behavior of the imaging tool and its impact on the transfer of mask LER to the wafer. Highfrequency mask LER...

PURPOSE We retrospectively explored the use of the delayed mask technique for intraarterial digital subtraction angiography (IADSA) to demonstrate the anatomy of aneurysm necks. METHODS The delayed mask technique was utilized in 22 patients who had craniotomies for aneurysms demonstrated at angiography. The operative notes were compared to the angiographic findings of both the traditionally m...

Object substitution is a type of backward masking that occurs when a mask appears during visual search for a target. We tested the hypothesis that object substitution is an overwriting process triggered by attentional selection of the mask. Impeding attentional selection of a mask by embedding it in an array of distractors eliminated object substitution. Similarly, object substitution did not o...