Extreme ultraviolet lithography process and mask

摘要

The present disclosure is directed towards lithography processes. In one embodiment, a patterned mask is provided. An information of a position of diffraction light (PDL) on a pupil plane of a projection optics box (POB) is used to define as a light-transmitting region of a pupil filter. The patterned mask is exposed by an on-axis illumination (ONI) with partial coherence σ less than 0.3. The pupil filter is used to transmit diffraction light to a target.

主权项

1. An extreme ultraviolet lithography (EUVL) process, comprising:
providing a patterned mask including a phase-defect region; receiving information of a position of diffraction light (PDL), diffracted from the patterned mask on a pupil plane of a projection optics box (POB); exposing the patterned mask by an on-axis illumination (ONI) with partial coherence σ less than 0.3; utilizing a pupil filter to control light intensity distribution diffracted from the patterned mask, the pupil filter including:
a light-transmitting region defined by the PDL; andrest of areas of the pupil filter set to be an opaque region; compensating, by the pupil filter, for a phase error caused by the phase-defect region at a time of exposure of the patterned mask; and collecting and directing the diffracted light from the patterned mask to expose a target.