Advances in multilayer reflective coatings for extreme ultraviolet lithography

Folta, James A.; Bajt, Saša; Barbee, Troy W.; Grabner, R. Fred; Mirkarimi, Paul B.; Nguyen, Tai D.; Schmidt, M.; Spiller, Eberhard; Walton, Christopher; Wedowski, Marco; Montcalm, Claude

doi:10.1117/12.351156

Cited by 36 publications

(8 citation statements)

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“…Here mask blanks are more demanding than mirrors as a much lower defect density is permitted, in addition to the requirements of high homogeneity, low surface and interface roughness, low stress, high temperature and photon flux stability [ 126 ]. Next to pulsed laser deposition [ 127 ] and magnetron sputtering [ 128 ], ion beam sputter deposition has been substantiated to allow for improved layer smoothness, intermixing suppression and stress reduction, as shown in Figure 16 [ 129 , 130 ].…”

Section: Selected Applicationsmentioning

confidence: 99%

Thin Film Deposition Using Energetic Ions

2010

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One important recent trend in deposition technology is the continuous expansion of available processes towards higher ion assistance with the subsequent beneficial effects to film properties. Nowadays, a multitude of processes, including laser ablation and deposition, vacuum arc deposition, ion assisted deposition, high power impulse magnetron sputtering and plasma immersion ion implantation, are available. However, there are obstacles to overcome in all technologies, including line-of-sight processes, particle contaminations and low growth rates, which lead to ongoing process refinements and development of new methods. Concerning the deposited thin films, control of energetic ion bombardment leads to improved adhesion, reduced substrate temperatures, control of intrinsic stress within the films as well as adjustment of surface texture, phase formation and nanotopography. This review illustrates recent trends for both areas; plasma process and solid state surface processes.

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Section: Selected Applicationsmentioning

confidence: 99%

Thin Film Deposition Using Energetic Ions

2010

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“…The samples that we investigated were Si/ Mo multilayers, which are important reflective coatings for extreme ultraviolet ͑EUV͒ projection lithography, 28,29 and samples of superior and well-characterized qualities are available. Our samples were deposited on Si͗100͘ substrates using an ultraclean ion beam sputtering system, which is known for its ability to produce ultrahigh quality masks for EUV lithography.…”

Section: Methodsmentioning

confidence: 99%

A study on the transmission of picosecond ultrasonic waves in Si∕Mo superlattices

Kuo

Pan

2008

Journal of Applied Physics

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We have performed theoretical and experimental studies on the optical generation and transmission of picosecond ultrasonic pulses in a-Si/ Mo superlattices using ultrafast lasers. The pulse shapes and spectra of collectively excited folded phonon waves were analyzed. Calculations show that the picosecond strain pulses transmitted through a superlattice have a very complicated waveform due to branch folding and phononic bandgaps, but the transient piezoreflectance ͑TPR͒ response has a rather simple shape, similar to that of a homogeneous thin film. A direct pulse-echo technique was used to measure the waveform of the TPR response and the effective sound velocity of the folded phonons. The experimental results agree well with the theoretical predictions.

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“…For 13.5 nm wave length, Mo/Si multi-layers have more than 70 % reflectivity for the normal incident reflection [2,3]. Also, the possible precision of the measurement of the shape of the mirror is a few nm.…”

Section: Telescope Designmentioning

confidence: 99%

Evaluation of an ultra-high-precision x-ray optics

Kitamoto

Yamamoto

Kohmura

et al. 2004

UV and Gamma-Ray Space Telescope Systems

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We are developing an ultra high precision soft X-ray telescope. The design of the telescope is a normal incident one for 13.5nm band using Mo/Si multilayers. Two ideas are introduced. One is the optical measurement system in order to monitor the precision of the optics system. The other is the adaptive optics system with a deformable mirror.Using an X-ray-optical separation filter, we can always monitor the deformation of the optics by optical light. With this information, we can control the deformable mirror to compensate the system distortion as a closed loop system.The telescope system is now integrating and checking by optical light. The shape of the primary mirror is an off-axis paraboloid with a focal length of 2m and an effective diameter of 80mm. This primary mirror was coated by Mo/Si multilayers. The reflectivity of the primary mirror at 13.5nm was ranging from 30 to 50 %. The secondary mirror is a basically flat mirror but actually an deformable mirror with 31 piezo-actuators. The detector is now a wave front sensor (shack-hartmann type). The closed loop control has been performed and factor of 2.4 improvement of the wave front shape has been performed comparing to the un-control case.

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Advances in multilayer reflective coatings for extreme ultraviolet lithography

Cited by 36 publications

References 0 publications

Thin Film Deposition Using Energetic Ions

Thin Film Deposition Using Energetic Ions

A study on the transmission of picosecond ultrasonic waves in Si∕Mo superlattices

Evaluation of an ultra-high-precision x-ray optics

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