Plane-parallel resonator configuration is proposed for high-NA EUV lithography, where the lithography mask and the wafer are parallelly arranged through two focusing mirrors. EUV light is injected through an off-axis rotating mirror at the back focal plane and provides off-axis illumination (precession beam) to the mask and bounces back twice (at the mask and the wafer), finally goes out from the resonator through the rotating mirror. This is a single path cavity, there is no resonant effect. The orbital error or vibration of the rotating mirror do not affect on the imaging quality. The off-axis illumination is essential for high-NA optics, which recovers the high spatial frequency, and improves the edge contrast. The matched annular-aperture is located at the back-focal plane of the projector mirror, which acts as Fourier filter passing only the horizontally scattered waves reflected by the density modulations F(kx,ky,0) : 0-th z-order Fourier component of the mask. During single precession of the beam, this system creates 2D image of the normally projected density map of the mask pattern onto the wafer, where the longitudinal variation (3D effect) disappears, and thus the mask-shadowing problem is moderated. The depth-of-focus (DOF) is long, and also the image contrast becomes very high. As the objective mirror, Schwarzschild objective or Wolter telescope will be a suitable candidate. Wolter telescope is axisymmetric and lighter than conventional solid concave mirror, therefore, a larger diameter can be fabricated in high precession. By optimizing Wolter telescope, it may be possible to cover the wafer field size 26 mm x 33 mm of single patterning. Example parameter design was performed, seems technically feasible.
Institute of Microelectronics of Chinese Academy of Sciences（中国科学院微电子研究所）；Paul Scherrer Institute（保罗谢尔研究所）；State Key Laboratory of Fabrication Technologies for Integrated Circuits（集成电路制造技术国家重点实验室）；University of Chinese Academy of Sciences（中国科学院大学）；Beijing Institute of Technology（北京理工大学）；Hyper Optics（海普光学）
Pseudo-spectral frequency-domain method with background field decomposition and Green's function preconditioner for electromagnetic scattering problem in EUV lithography
Mask-based pattern generation is a crucial step in microchip production. The next-generation extreme-ultraviolet- (EUV) lithography instruments with a wavelength of \SI{13.5}{\nano\meter} is currently under development. In principle, this should allow patterning down to a resolution of a few nanometers in a single exposure. However, there are many technical challenges, including those due to the very high energy of the photons. Lithography with metastable atoms has been suggested as a cost-effective, less-complex alternative to EUV lithography. The great advantage of atom lithography is that t…
In this paper, a method for solving the initial structure of an off-axis multi-mirror system applied to extreme ultraviolet (EUV) lithography using a paraxial ray-tracing algorithm based on Seidel aberration theory is proposed. By tracing the characteristic rays in the reflection system, the height and paraxial angle on each surface can be obtained, then through the relationship between the Seidel aberration coefficient and these parameters, the initial structure with good aberration performance can be solved. We can obtain different initial structures by adding different initial condition con…
40% boost in extreme ultraviolet conversion efficiency via simultaneous dual-beam 2-μm laser irradiation
Utsunomiya University（宇都宫大学）；RIKEN Center for Advanced Photonics, RIKEN（理化学研究所先进光子学研究中心）；The University of Tokyo（东京大学）；Tohoku University（东北大学）；University College Dublin（都柏林大学学院）；Hiroshima University（广岛大学）
Microring resonators are critical photonic components used in filtering, sensing and nonlinear applications. To date, the development of high performance microring resonators in LNOI has been limited by the sidewall angle, roughness and etch depth of fabricated rib waveguides. We present large free spectral range microring resonators patterned via electron beam lithography in high-index contrast $Z$-cut LNOI. Our microring resonators achieve an FSR greater than 5 nm for ring radius of 30 $μ$m and a large 3 dB resonance bandwidth. We demonstrate 3 pm/V electro-optic tuning of a 70 $μ$m-radius r…
Freestanding Silicon nitride (SiN) devices are central to the field of nanomechanical resonators and for other technology applications such as transmission electron imaging and nanopore bioassays. The nanofabrication techniques used for fabricating these devices often lack flexibility. While photolithography requires printing of an expensive photomask for each new design iteration, electron-beam lithography is extremely slow and commands high equipment cost. Here we demonstrate maskless rapid prototyping of freestanding SiN nanomechanical resonators fabricated by femtosecond laser ablation of …
Fast production of large area patterns with nanometre resolution is crucial for the established semiconductor industry and for enabling industrial-scale production of next-generation quantum devices. Metastable atom lithography with binary holography masks has been suggested as a higher resolution/low-cost alternative to the current state of the art: extreme ultraviolet (EUV) lithography. However, it was recently shown that the interaction of the metastable atoms with the mask material (SiN) leads to a strong perturbation of the wavefront, not included in existing mask generation theory, which…
