Extreme ultraviolet lithography process and mask

摘要

A process of an extreme ultraviolet lithography (EUVL) is disclosed. The process includes receiving an extreme ultraviolet (EUV) mask with multiple states. Different states of the EUV mask are assigned to adjacent polygons and a field. The EUV mask is exposed by a nearly on-axis illumination (ONI) with partial coherence σ less than 0.3 to produce diffracted lights and non-diffracted lights. Most of the non-diffracted lights are removed. The diffracted lights and the not removed non-diffracted lights are collected and directed to expose a target by a projection optics box.

主权项

1. An extreme ultraviolet lithography (EUVL) process for patterning a target, comprising:
providing an extreme ultraviolet (EUV) mask having an absorption stack disposed on a reflective multilayer (ML), wherein the absorption stack provides multiple reflective states including a first reflective state and a second reflective state, wherein the first reflective state is provided by an exposed top surface of a first absorption stack layer and the second reflective state is provided by an exposed top surface of a second absorption stack layer; illuminating the EUV mask with an EUV light source providing an incident beam of a nearly on-axis illumination (ONI) with partial coherence σ less than 0.3; reflecting the incident beam from the EUV mask thereby producing diffracted light and non-diffracted light using the multiple reflective states of the EUV mask; removing a portion of the reflected, non-diffracted light; and collecting and directing the reflected, diffracted light and an unremoved portion of non-diffracted light with a projection optics box (POB) to expose the target.