The power of algorithmic employed in a metrology system: AIMS EUV Digital Flex Illu

Abstract

Digital Flex Illu is a fully digital solution which provides SMO functionality to the AIMS ® EUV system by combining an adaptation of the already built-in system metrology with a powerful algorithm and most importantly, without changing the machine hardware. In this paper, we will present the concept of Digital Flex Illu functionality, its significant advantages in combination with a binary aperture-based illumination concept, together with showing imaging results obtained on the AIMS ® EUV prototype system. This digital solution is a paradigm change for the AIMS ® EUV usability and final user, it allows ZEISS to guarantee an agile roadmap for the AIMS ® EUV with limited development effort and great benefits in sustainability and roadmap scaling.

Actinic EUV mask qualification for next generation lithography

“…Here, the illumination design contains information over the whole optical path to compensate for any difference within the light cones between metrology and the corresponding scanner system. [8] The technique has, however, the drawback of a missing flexibility, since for every SMO setting in use within a production environment a dedicated hardware blade is required. Figure 5.…”

“…To meet the requirements of both scanner matching and a full and fast flexibility to scanner SMO illumination profiles, the photomask metrology technique can be complemented by a suitable process that combines aerial image measurement with powerful imaging algorithms (Digital Flex Illumination). [8] The basic idea of the procedure is to first capture aerial image information under various exposure conditions like defocus and illumination shift, and then to derive a very essential and useful property of the mask structure, the so-called object spectrum, from an optimization loop. The object spectrum of the mask in general is dependent on the angle of incidence, so a proper mask modelling is required to obtain a preferably compact form of the diffraction pattern information.…”

“…Once the sigma-dependent object spectrum of the mask is known, synthetical aerial images with profound scanner matching quality can be obtained via a forward imaging calculation using the scanner spot illumination profile. [8]…”