Characterization of collector optic material samples exposed to a discharge-produced plasma extreme ultraviolet light source

Alman, D. A.; Qiu, Huatan; Spila, T.; Thompson, Keith C.; Antonsen, Erik L.; Jurczyk, Brian E.; Ruzic, D. N.

doi:10.1117/1.2437212

Cited by 6 publications

(4 citation statements)

References 12 publications

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“…This paper reports a part of the Collector Lifetime and Erosion Project at the University of Illinois at Urbana-Champaign (UIUC) [1][2][3] , sponsored by SEMATECH and operated in cooperation with Intel Corporation and Xtreme Technologies GmbH. The purpose of this project is to examine the effects of ion debris interaction with the primary collector optic in commercial EUV sources to ascertain the fundamental erosion processes and critical lifetime issues facing high-volume manufacturing (HVM) for EUV lithography.…”

Section: Introductionmentioning

confidence: 98%

Optical exposure characterization and comparisons for Sn EUV systems

et al. 2006

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A critical issue for EUVL is the minimization of collector degradation from intense plasma erosion, debris deposition and hydrocarbon/oxide contamination. Collector optics reflectivity and lifetime heavily depends on surface chemistry and interactions between fuels and various mirror materials, such as silicon, in addition to high-energy ion and neutral particle erosion effects. As a continuation of our prior investigation of DPP and LPP Xe plasma interactions with collector optics surfaces, the University of Illinois has analyzed collector samples before and after exposure in a Sn-upgraded Xtreme Technologies EUV source. Sn DPP post-exposure characterization includes multiple samples, Si/Mo multilayer film with normal incidence, 200 nm thick Ru film with grazing incidence, as well as a Gibbsian segregated (GS) Mo-Au alloy developed on silicon using a DC dualmagnetron co-sputtering system at UIUC. Pre and post exposed sample characterization studies actually investigates the surface roughness properties, erosion resistance and self-healing characteristics to maintain reflectivity over a longer period of mirror lifetime. Surface analysis draws heavily on the expertise of the Center for Microanalysis of Materials at UIUC, and investigates mirror degradation mechanisms by measuring changes in surface roughness, texture, and grain sizes as well as analysis of the implantation of energetic Sn ions, Sn diffusion, and mixing of multi-layers. Results from atomic force microscopy (AFM) and auger electron spectroscopy (AES) measurements show exposure effects on surface roughness and contamination. The best estimates of thickness and the resultant erosion measurements are obtained from scanning electron microscopy (SEM). Implantation, diffusion, and mixing effects are analyzed with depth profiles using AES. Materials characterization on samples, removed after varying exposure times in the XTS source, together with in-situ EUV reflectivity measurements, can identify the onset of different degradation mechanisms within each sample. These samples are the first fully characterized materials to be exposed to a Sn-based DPP EUV source. Several valuable and interesting facts were noticed. First, hot mirrors exposed to SnCl 4 will cause decomposition of the gas and will result into a contamination layer build up on the mirror surface. Secondly, erosion is mitigated to some extent by the simultaneous deposition of material. Third and most important is that the Gibbsian segregation concept works and a thin Au layer is maintained during the entire exposure, even though overall erosion took place. This phenomenon could be very useful in the design and development of a collector optics surface. In addition, this paper will present Sn DPP collector erosion mechanisms, source debris spectra and provide insight into plasma-facing optics lifetime as HVM tool conditions are approached.

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Section: Introductionmentioning

confidence: 98%

Optical exposure characterization and comparisons for Sn EUV systems

et al. 2006

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“…Some examples are the characterization and processing of materials [3][4][5][6]; techniques for high-resolution metrology [7][8][9][10][11]; studies in atomic physics, photochemistry, and photophysics [12,13]; biological imaging [14][15][16][17]; the diagnosis of very high-density plasmas [18][19][20][21]; the study of nonlinear phenomena [22,23]; and even integrated circuit lithography [24].…”

Section: Introductionmentioning

confidence: 99%

Design of a phase-shifting interferometer in the extreme ultraviolet for high-precision metrology

2014

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The design of a phase-shift interferometer in the extreme ultraviolet (EUV) is described. The interferometer is expected to achieve a significantly higher precision as compared with similar instruments that utilize lasers in the visible range. The interferometer's design is specifically adapted for its utilization with a table top pulsed capillary discharge EUV laser. The numerical model evaluates the errors in the interferograms and in the retrieved wavefront induced by the shot-to-shot fluctuations and pointing instabilities of the laser.

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“…An innovative idea using the Gibbsian segregation (GS) concept as the potential grazing incident EUV collector optics is developed and explored [10][11][12][13]. GS processes have been defined [14,15] as the tendency of certain solute elements in a homogenously interspersed solid solution to accumulate at imperfections, such as grain boundaries and interfaces in the bulk lattice that then may segregate to the free sur-faces.…”

Section: Introductionmentioning

confidence: 99%

“…If the regenerative transport processes (bulk, grain, interface diffusion) and surface renormalization are faster than the erosion time scale (i.e., the average time between large energy sputtering events), then the collector optics would be self-repairing. Early works have been published to assess the suitability of the GS alloy technology for early adoption of EUV lithography and test the validity with the theoretical estimate [10][11][12][13]. This work describes further experimental efforts to discover if GS alloys effectively ameliorate and self-heal the damage in grazing incidence EUV collector optics.…”

Section: Introductionmentioning

confidence: 99%

Time exposure performance of Mo-Au Gibbsian segregating alloys for extreme ultraviolet collector optics

et al. 2008

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Successful implementation of extreme ultraviolet (EUV) lithography depends on research and progress toward minimizing collector optics degradation from intense plasma erosion and debris deposition. Thus studying the surface degradation process and implementing innovative methods, which could enhance the surface chemistry causing the mirrors to suffer less damage, is crucial for this technology development. A Mo-Au Gibbsian segregation (GS) alloy is deposited on Si using a dc dual-magnetron cosputtering system and the damage is investigated as a result of time dependent exposure in an EUV source. A thin Au segregating layer is maintained through segregation during exposure, even though overall erosion in the Mo-Au sample is taking place in the bulk. The reflective material, Mo, underneath the segregating layer is protected by this sacrificial layer, which is lost due to preferential sputtering. In addition to theoretical work, experimental results are presented on the effectiveness of the GS alloys to be used as potential EUV collector optics material.

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Characterization of collector optic material samples exposed to a discharge-produced plasma extreme ultraviolet light source

Cited by 6 publications

References 12 publications

Optical exposure characterization and comparisons for Sn EUV systems

Optical exposure characterization and comparisons for Sn EUV systems

Design of a phase-shifting interferometer in the extreme ultraviolet for high-precision metrology

Time exposure performance of Mo-Au Gibbsian segregating alloys for extreme ultraviolet collector optics

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