Dirk Hellweg

Generation of arbitrary freeform source shapes using advanced illumination systems in high-NA immersion scanners

The application of customized and freeform illumination source shapes is a key enabler for continued shrink using 193 nm water based immersion lithography at the maximum possible NA of 1.35. In this paper we present the capabilities of the DOE based Aerial XP illuminator and the new programmable FlexRay illuminator. Both of these advanced illumination systems support the generation of such arbitrarily shaped illumination sources. We explain how the different parts of the optical column interact in forming the source shape with which the reticle is illuminated. Practical constraints of the systems do not limit the capabilities to utilize the benefit of freeform source shapes vs. classic pupil shapes. Despite a different pupil forming mechanism in the two illuminator types, the resulting pupils are compatible regarding lithographic imaging performance so that processes can be transferred between the two illuminator types. Measured freeform sources can be characterized by applying a parametric fit model, to extract information for optimum pupil setup, and by importing the measured source bitmap into an imaging simulator to directly evaluate its impact on CD and overlay. We compare measured freeform sources from both illuminator types and demonstrate the good matching between measured FlexRay and DOE based freeform source shapes.

Actinic review of EUV masks: first results from the AIMS EUV system integration

The EUV mask infrastructure is of key importance for a successful introduction of EUV lithography into volume production. In particular, for the production of defect free masks, actinic review of potential defect sites is required. To realize such an actinic review tool, Zeiss and the SEMATECH EUVL Mask Infrastructure consortium started a development programme for an EUV aerial image metrology system (AIMS™ EUV). In this paper, we discuss the status of the on-going system integration and show first results from the first light tests of the prototype tool.

Concept and feasibility of aerial imaging measurements on EUV masks

On the road to and beyond the 22nm half-pitch on chip patterning technology, 13.5nm EUVL is widely considered the best next technology generation following deep ultraviolet lithography. The availability of an actinic measurement system for the printability analysis of mask defects to ensure defect-free mask manufacturing and cost-effective high-volume EUV production is an infrastructural prerequisite for the EUVL roadmap and represents a significant step toward readiness for commercialization of EUV for high-volume-manufacturing . Carl Zeiss and SEMATECHs EUVL Mask Infrastructure (EMI) program started a concept study and feasibility plan for a tool that emulates the aerial image formed by a EUV lithography scanner supporting the 22 nm half-pitch node requirements with extendibility to the 16nm half-pitch node. The study is targeting a feasible concept for the AIMSTM EUV platform, bridging a significant gap for EUV mask metrology.

Actinic review of EUV masks: Status and recent results of the AIMS EUV system

The EUV mask infrastructure is of key importance for the successful introduction of EUV lithography into volume production. In particular, for the production of defect free masks an actinic review of potential defect sites is required. To realize such an actinic review tool, Carl Zeiss and the SEMATECH EUVL Mask Infrastructure consortium started a development program for an EUV aerial image metrology system, the AIMS™ EUV. In this paper, we discuss the current status of the prototype integration and show recent results.

AIMS EUV first light imaging performance

Overcoming the challenges associated with photomask defectivity is one of the key aspects associated with EUV mask infrastructure. In addition to establishing specific EUV mask repair approaches, the ability to identify printable mask defects that require repair as well as to verify if a repair was successful are absolutely necessary. Such verification can only be performed by studying the repaired region using actinic light at an exact emulation of the scanner illumination conditions of the mask as can be done by the AIMSTM EUV. ZEISS, in collaboration with the SEMATECH EUVL Mask Infrastructure (EMI) consortium are currently developing the AIMSTM EUV system and have recently achieved First Light on the prototype system, a major achievement. First light results will be presented in addition to the current development status of the system.

Status of the AIMS EUV development project

The need for an actinic wavelength AIMS™ EUV tool by 2014 has been defined by SEMATECH due to the challenges associated with EUV mask manufacture and defectivity. The AIMS™ EUV development project began in June of 2011 as a collaboration between ZEISS and the SEMATECH EUVL Mask Infrastructure (EMI) consortium. The project remains on track to meet the first commercial tool shipment in September 2014. The current design status of the system after two years as well as recent progress in the prototype build will be presented.

Development status and infrastructure progress update of aerial imaging measurements on EUV masks

The high volume device manufacturing infrastructure for the 22nm node and below based on EUVL technology requires defect-free EUV mask manufacturing as one of its foundations. The EUV Mask Infrastructure program (EMI) initiated by SEMATECH has identified an actinic measurement system for the printability analysis of EUV mask defects to ensure defect free mask manufacturing and cost-effective high-volume EUV production as an infrastructural prerequisite for the EUVL roadmap ([1], [2]). The Concept and Feasibility study for the AIMSTM EUV resulted in a feasible tool concept for 16nm defect printability review. The main development program for the AIMSTM EUV has been started at Carl Zeiss leading to a commercialized tool available in 2014. In this paper we will present the status of the progress of the design phase of this development and an infrastructure progress update of the EUV Mask defect printability review.

Actinic review of EUV masks: performance data and status of the AIMS EUV System

The EUV mask infrastructure is of key importance for the successful introduction of EUV lithography into volume production. In particular, for the production of defect free masks an actinic review of potential defect sites is required. ZEISS and the SUNY POLY SEMATECH EUVL Mask Infrastructure consortium started a development program for such an EUV aerial image metrology system, the AIMS EUV. In this paper, we provide measurement data on the system’s key specifications and discuss its performance and capability status.

Extending KrF lithography beyond 80nm with the TWINSCAN XT:1000H 0.93NA scanner

KrF lithography is nowadays widely used for volume production spanning many device layers ranging from front-end 90nm to mid- & back-end layers in 45nm and 32nm ITRS imaging nodes. In this paper we discuss the addition of the new high-NA XT:1000H TWINSCAN(TM)scanning exposure tool to the KrF portfolio. We discuss advances in the system design and elaborate on its imaging and overlay performance. It is shown that stable tool performance supports 80nm resolution volume manufacturing. Extendibility with polarization towards sub-80nm is also addressed.

AIMS™ EUV tool platform: aerial-image based qualification of EUV masks (Conference Presentation)

With the EUV high volume manufacturing becoming reality and the closing gap of EUV mask infrastructure, EUV lithography is seeing or will shortly see the first production chips being fabricated with EUV. Pilot production in EUV HVM is most likely realized in a mix-and-match process with 193nm techniques. The degree of complexity introduced by the EUV lithographic process is transferred in parallel also to EUV mask: the combination of process sensitive 3D effects and material dependent EUV reflectivity make even the simplest EUV mask what the community is recognizing to be a very complex phase object. The qualification of such a complex piece of Infrastructure as the EUV mask is being addressed from many directions: defect review application is always more backed up by ancillary applications which aim at qualifying the printing behavior of the mask with the fundamental precondition of a full scanner emulation. ZEISS and the SUNY POLY SEMATECH EUVL Mask Infrastructure consortium have developed and commercialized the EUV aerial image metrology platform, the AIMS™ EUV platform, which fully addresses the industry requirements for EUV defectivity review. Additionally, this tool platform allows for mask qualification applications based on the employment of aerial image proven technology. In this paper, the status and recent achievements of the AIMSTM EUV platform will be presented. Promoting the detailed exploration of the aerial image content potential for EUV process understanding and mask qualification, we will present recent results on a printability study of embedded EUV multilayer defects, along with providing further insights into the relevance of mask 3D effects.