Giovanni Bianucci

Development and performance of grazing and normal incidence collectors for the HVM DPP and LPP sources

Media Lario Technologies (MLT), leveraging off its unique in-field collector experience, has designed the Grazing Incidence Collector (GIC) for the Sn-fueled Discharge Produced Plasma (DPP) source developed by Philips Extreme UV (PEUV) and XTREME technologies (XT) for High Volume Manufacturing (HVM) deployment. The performance of the HVM GIC described in this work shows a point-source collection efficiency of 24%, and is enabled by an integrated thermal control system designed to ensure optical stability for an absorbed thermal load of 6 kW. The GIC reflective layer has been custom tailored to match the debris mitigation strategy developed and characterized by PEUV and XT, supporting at least a 1-year lifetime proposition of the source-collector module. Leveraging off the experience gained in GIC, MLT is developing the processes to manufacture the Normal Incidence Collector (NIC) for Laser Produced Plasma (LPP) sources. Using its proprietary disruptive replication technology by electroforming, MLT is developing thermal management designs for NIC enabling stable operation at room temperature. This work reports on the performance of (symbol) 150 mm thermally managed NIC demonstrators. The mirror substrates have been integrated with new proprietary thermal management designs that are well suited to the electroformed mirrors. We also report on the reflectivity of the Mo/Si multilayer coated mirror, achieving maximum reflectivity values of 62% and a center wavelength (FWHM) of 13.52 nm, which demonstrates acceptable performance in an LPP NIC application.

Thermal management design and verification of collector optics into high-power EUV source systems

A dual-mirror grazing incidence collector produced by Media Lario Technologies was integrated into a high-power, Xefueled gas discharge produced plasma (GDPP) source test stand at XTREME technologies, and tested at power levels responding to the productivity demands of the extreme ultra-violet (EUV) lithography beta exposure systems. The test campaign conducted at different source repetition rates in steady state and transient operating modes provided data for the verification and improvement of the thermo-optical model of the source-DMT-collector system used for the thermooptical design of the collector. The final thermo-optical model of the steady state regime was cross-validated by the numerical solution of the transient tests, which is solely based on the experimental temperature readings. Among the salient results, the cooling system integrated on the collector removed the 1 kW heat load absorbed by the dual-mirror optics, maintaining the temperature of the optics within 20-25 °C temperature range, with an input cooling water temperature of 18.6 °C. Additional validation came from tests performed on a single-mirror collector in a vacuum based, thermo-optical visible test bench installed at Media Lario Technologies, which provided a closed loop validation of the thermal budget, finite element model, and Monte Carlo ray tracing optical prediction.

Characterization and qualification of the Jeol JBX9000-MVII e-beam writer for the 90nm node and its integration in a photomask manufacturing line

The advanced Jeol JBX9000MVII 50kV electron-beam lithography system has been successfully installed at DNP Photomask Europe and timely qualified for the 90nm technology node. The overall performances of this writing tool have thoroughly been assessed on positive and negative tone chemically amplified resists (CARs), fully exploiting the advanced proximity effect correction (PEC) capabilities of the system and carefully optimizing the overall process. The reported results show the machine capabilities in terms of global and local pattern placement and CD accuracy, CD linearity, pattern fidelity, along with data on some of the most demanding model-based OPC validation patterns. Details on process characterization and tuning effectiveness on resist and chrome are shown, including the PEC approach. Based on the stringent metrology correlation achieved with DNP Japan manufacturing site, the data show a one-to-one compatibility with the sister tool installed there, even on the most critical OPC structures. Consequently, the complete product interchangeability between the two manufacturing sites has been achieved.

Optical integration of SPO mirror modules in the ATHENA telescope

ATHENA (Advanced Telescope for High-ENergy Astrophysics) is the next high-energy astrophysical mission selected by the European Space Agency for launch in 2028. The X-ray telescope consists of 1062 silicon pore optics mirror modules with a target angular resolution of 5 arcsec. Each module must be integrated on a 3 m structure with an accuracy of 1.5 arcsec for alignment and assembly. This industrial and scientific team is developing the alignment and integration process of the SPO mirror modules based on ultra-violet imaging at the 12 m focal plane. This technique promises to meet the accuracy requirement while, at the same time, allowing arbitrary integration sequence and mirror module exchangeability. Moreover, it enables monitoring the telescope point spread function during the planned 3-year integration phase.

A development roadmap for critical technologies needed for TALC: a deployable 20m annular space telescope

Astronomy is driven by the quest for higher sensitivity and improved angular resolution in order to detect fainter or smaller objects. The far-infrared to submillimeter domain is a unique probe of the cold and obscured Universe, harboring for instance the precious signatures of key elements such as water. Space observations are mandatory given the blocking effect of our atmosphere. However the methods we have relied on so far to develop increasingly larger telescopes are now reaching a hard limit, with the JWST illustrating this in more than one way (e.g. it will be launched by one of the most powerful rocket, it requires the largest existing facility on Earth to be qualified). With the Thinned Aperture Light Collector (TALC) project, a concept of a deployable 20 m annular telescope, we propose to break out of this deadlock by developing novel technologies for space telescopes, which are disruptive in three aspects: • An innovative deployable mirror whose topology, based on stacking rather than folding, leads to an optimum ratio of collecting area over volume, and creates a telescope with an eight times larger collecting area and three times higher angular resolution compared to JWST from the same pre-deployed volume; • An ultra-light weight segmented primary mirror, based on electrodeposited Nickel, Composite and Honeycomb stacks, built with a replica process to control costs and mitigate the industrial risks; • An active optics control layer based on piezo-electric layers incorporated into the mirror rear shell allowing control of the shape by internal stress rather than by reaction on a structure. We present in this paper the roadmap we have built to bring these three disruptive technologies to technology readiness level 3. We will achieve this goal through design and realization of representative elements: segments of mirrors for optical quality verification, active optics implemented on representative mirror stacks to characterize the shape correction capabilities, and mechanical models for validation of the deployment concept. Accompanying these developments, a strong system activity will ensure that the ultimate goal of having an integrated system can be met, especially in terms of (a) scalability toward a larger structure, and (b) verification philosophy.

Low CoO grazing incidence collectors for EUVL HVM

Media Lario Technologies (MLT) uses its proprietary replication by electroforming technology to manufacture grazing incidence collectors in support of the EUVL technology roadmap. With the experience of more than 20 alpha and preproduction collectors installed to date, and with the development results of the Advanced Cooling Architecture (ACA) for High Volume Manufacturing (HVM) collector generation, we present optical, lifetime, and thermo-optical performance of the grazing incidence collectors, meeting the requirements of HVM scanners for a throughput target of more than 100 wafers per hour. The ruthenium reflective layer of the grazing incidence collector is very forgiving to the hostile environment of the plasma sources, as proven by the installed base with 1-year lifetime expectancy. On the contrary, the multilayer-based collector is vulnerable to Sn deposition and ion bombardment, and the need to mitigate this issue has led to a steady increase of the complexity of the LPP source architecture. With the awareness that the source and collector module is the major risk against the timely adoption of EUVL in HVM, we propose a new paradigm that, by using the field-proven design simplicity and robustness of the grazing incidence collector in both LDP and LPP sources, effectively reduces the risk of both source architectures and improves their reliability.

Design and fabrication considerations of EUVL collectors for HVM

The power roadmap for EUVL high volume manufacturing (HVM) exceeds the 200W EUV in-band power at intermediate focus, thus posing more demanding requirements on HVM sources, debris suppression systems and collectors. Starting from the lessons learned in the design and fabrication of the grazing incidence collectors for the Alpha EUVL scanners, Media Lario Technologies is developing HVM optical solutions that enable designed-in lifetime improvements, such as larger source-collector distances, optimized collection efficiency through larger collected solid angles, and customized EUV reflective layers. The optical design of an HVM collector is described together with the selection of the sacrificial ruthenium reflective layer. The water cooling layout of the collector is evolved from the integrated cooling technology developed at Alpha level into an innovative cooling layout that minimizes the thermal gradients across the mirrors and allows controlling the optical performance at the far-field plane. Finally, the evolution of the collectors manufacturing technologies for HVM is discussed. XTREME technologies and Philips Extreme UV support this work by integrating the collector in the complete source collector module (SoCoMo). At system level, each component of the SoCoMo is part of a development and improvement plan leading to a comprehensive system that will fulfill the 200+ W EUV in-band power at intermediate focus.

Thermal and Optical Characterization of Collectors Integrated in a Sn-DPP based SoCoMo

The paper presents the results of an investigation into the thermal and optical characteristics of alpha-type dual-mirror grazing incidence collectors for Extreme Ultra-violet Lithography integrated into a tin-fueled discharge produced plasma source. The performance of the system is assessed at various power levels and temperature conditions. The thermal and the optical data, in particular images at extra-focal planes behind the intermediate focus, are compared to the predictions of the thermo-optical model of the system. The data we present provide verification of the models used to design the collector and validation of the thermo-optical modeling approach for design of future generations of collectors.

Optical simulations for design, alignment, and performance prediction of silicon pore optics for the ATHENA x-ray telescope (Conference Presentation)

The ATHENA X-ray observatory is a large-class ESA approved mission, with launch scheduled in 2028. The technology of silicon pore optics (SPO) was selected as baseline to assemble ATHENA’s optic with hundreds of mirror modules, obtained by stacking wedged and ribbed silicon wafer plates onto silicon mandrels to form the Wolter-I configuration. In the current configuration, the optical assembly has a 3 m diameter and a 2 m2 effective area at 1 keV, with a required angular resolution of 5 arcsec. The angular resolution that can be achieved is chiefly the combination of 1) the focal spot size determined by the pore diffraction, 2) the focus degradation caused by surface and profile errors, 3) the aberrations introduced by the misalignments between primary and secondary segments, 4) imperfections in the co-focality of the mirror modules in the optical assembly. A detailed simulation of these aspects is required in order to assess the fabrication and alignment tolerances; moreover, the achievable effective area and angular resolution depend on the mirror module design. Therefore, guaranteeing these optical performances requires: a fast design tool to find the most performing solution in terms of mirror module geometry and population, and an accurate point spread function simulation from local metrology and positioning information. In this paper, we present the results of simulations in the framework of ESA-financed projects (SIMPOSiuM, ASPHEA, SPIRIT), in preparation of the ATHENA X-ray telescope, analyzing the mentioned points: 1) we deal with a detailed description of diffractive effects in an SPO mirror module, 2) we show ray-tracing results including surface and profile defects of the reflective surfaces, 3) we assess the effective area and angular resolution degradation caused by alignment errors between SPO mirror module’s segments, and 4) we simulate the effects of co-focality errors in X-rays and in the UV optical bench used to study the mirror module alignment and integration.

Simulating the optical performances of the ATHENA x-ray telescope optics

The ATHENA (Advanced Telescope for High Energy Astrophysics) X-ray observatory is an ESA-selected L2 class mission. In the proposed configuration, the optical assembly has a diameter of 2.2 m with an effective area of 1.4 m2 at 1 keV, 0.25 m2 at 6 keV, and requires an angular resolution of 5 arcsec. To meet the requirements of effective area and angular resolution, the technology of Silicon Pore Optics (SPO) was selected for the optics implementation. The ATHENA’s optic assembly requires hundreds of SPOs mirror modules (MMs), obtained by stacking wedged and ribbed silicon wafer plates onto silicon mandrels to form the Wolter-I configuration. Different factors can contribute to limit the imaging performances of SPOs, such as i) diffraction through the pore apertures, ii) plate deformations due to fabrication errors and surface roughness, iii) alignment errors among plates in an MM, and iv) co-focality errors within the MMs assembly. In order to determine the fabrication and assembling tolerances, the impact of these contributions needs to be assessed prior to manufacturing. A set of simulation tools responding to this need was developed in the framework of the ESA-financed projects SIMPOSIuM and ASPHEA. In this paper, we present the performance simulation obtained for the recentlyproposed ATHENA configuration in terms of effective area, and we provide a simulation of the diffractive effects in a pair of SPO MMs. Finally, we present an updated sizing of magnetic diverter (a Halbach array) and the magnetic fields levels that can be reached in order to deviate the most energetic protons out of the detector field.