You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither SPIE nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the SPIE website.
21 March 2006Applicability of alternating phase shifting masks using polarized light
The use of Alternating Phase Shifting Masks (APSM) for sub 50nm half pitch pattern using 193nm lithography was evaluated. Results show that polarized illumination may be necessary for APSM to compete with Half-Tone Phase-Shifting Masks (HTPSM) when printing sub 50nm features. The low sigma illumination conditions required for APSM constraints the choice of a possible polarized illuminator to the TE polarized option therefore limiting the patterns to be oriented in one direction.
Topography effects imply the use of polarization-dependant balancing of APSM which should not be a show-stopper as long as it is properly handled at the time the mask is manufactured. Due to topography effects, the MEEF is increased if compared to thin mask approximation but the relative numbers remain manageable.
The sensitivity of CD errors with respect to polarization errors of the source is comparable to HTPSM masks. The induced displacement due to polarization errors is small compared to the CD variation of the dark line.