Flexible and stretchable electronics can dramatically enhance the application of electronics for the emerging Internet of Everything applications where people, processes, data and devices will be integrated and connected, to augment quality of life. Using naturally flexible and stretchable polymeric substrates in combination with emerging organic and molecular materials, nanowires, nanoribbons, nanotubes, and 2D atomic crystal structured materials, significant progress has been made in the general area of such electronics. However, high volume manufacturing, reliability and performance per cost remain elusive goals for wide commercialization of these electronics. On the other hand, highly sophisticated but extremely reliable, batch-fabrication-capable and mature complementary metal oxide semiconductor (CMOS)-based technology has facilitated tremendous growth of today's digital world using thin-film-based electronics; in particular, bulk monocrystalline silicon (100) which is used in most of the electronics existing today. However, one fundamental challenge is that state-of-the-art CMOS electronics are physically rigid and brittle. Therefore, in this work, how CMOS-technology-enabled flexible and stretchable electronics can be developed is discussed, with particular focus on bulk monocrystalline silicon (100). A comprehensive information base to realistically devise an integration strategy by rational design of materials, devices and processes for Internet of Everything electronics is offered.

CMOS-Technology-Enabled Flexible and Stretchable Electronics for Internet of Everything Applications.

Interference lithography at EUV and soft X-ray wavelengths

We present a new concept for the generation of optical lattice waves. For all four families of nondiffracting beams, we are able to realize corresponding nondiffracting intensity patterns in a single setup. The potential of our approach is shown by demonstrating the optical induction of complex photonic discrete, Bessel, Mathieu and Weber lattices in a nonlinear photorefractive medium. However, our technique itself is very general and can be transferred to optical lattices in other fields such as atom optics or cold gases in order to add such complex optical potentials as a new concept to these areas as well.

https://www.uni-muenster.de/imperia/md/content/physik_ap/denz/publikationen/2012/07_rose.pdf

Nonlinear lattice structures based on families of complex nondiffracting beams

Extreme ultraviolet (EUV) lithography at 13.5 nm is the main candidate for patterning integrated circuits and reaching sub-10-nm resolution within the next decade. Should photon-based lithography still be used for patterning smaller feature sizes, beyond EUV (BEUV) lithography at 6.x nm wavelength is an option that could potentially meet the rigid demands of the semiconductor industry. We demonstrate simultaneous characterization of the resolution, line-edge roughness, and sensitivity of distinct photoresists at BEUV and compare their properties when exposed to EUV under the same conditions. By using interference lithography at these wavelengths, we show the possibility for patterning beyond 22 nm resolution and characterize the impact of using higher energy photons on the line-edge roughness and exposure latitude. We observe high sensitivity of the photoresist performance on its chemical content and compare their overall performance using the Z-parameter criterion. Interestingly, inorganic photoresists have much better performance at BEUV, while organic chemically-amplified photoresists would need serious adaptations for being used at such wavelength. Our results have immediate implications for deeper understanding of the radiation chemistry of novel photoresists at the EUV and soft X-ray spectra.

Beyond EUV lithography: a comparative study of efficient photoresists'

Extreme ultraviolet (EUV) lithography at 13.5 nm is the main candidate for patterning integrated circuits and reaching sub-10-nm resolution within the next decade. Should photon-based lithography still be used for patterning smaller feature sizes, beyond EUV (BEUV) lithography at 6.x nm wavelength is an option that could potentially meet the rigid demands of the semiconductor industry. We demonstrate simultaneous characterization of the resolution, line-edge roughness, and sensitivity of distinct photoresists at BEUV and compare their properties when exposed to EUV under the same conditions. By using interference lithography at these wavelengths, we show the possibility for patterning beyond 22 nm resolution and characterize the impact of using higher energy photons on the line-edge roughness and exposure latitude. We observe high sensitivity of the photoresist performance on its chemical content and compare their overall performance using the Z-parameter criterion. Interestingly, inorganic photoresists have much better performance at BEUV, while organic chemically-amplified photoresists would need serious adaptations for being used at such wavelength. Our results have immediate implications for deeper understanding of the radiation chemistry of novel photoresists at the EUV and soft X-ray spectra.

/pdf/beyond-euv-lithography-a-comparative-study-of-efficient-dcewgpb1kh.pdf

Beyond EUV lithography: a comparative study of efficient photoresists' performance.

We experimentally investigate the formation of reconfigurable three-dimensional (3D) nonlinear photonic lattices in an externally biased cerium doped strontium barium niobate photorefractive crystal by a spatial light modulator-assisted versatile simplified single step optical induction approach. The analysis of the generated 3D nonlinear photonic lattices by plane wave guiding, momentum space spectroscopy, and far field diffraction pattern imaging is presented, which points to the embedded potential of these 3D structures as reconfigurable platform to investigate advanced nonlinear light-matter interaction in periodic structures.

https://www.uni-muenster.de/imperia/md/content/physik_ap/denz/publikationen/2009/15_opt_lett_xavier.pdf

Three-dimensional optically induced reconfigurable photorefractive nonlinear photonic lattices

The performance of EUV resists is a key factor for the cost-effective introduction of EUV lithography. Although most of
the global effort concentrates on resist performance at 22 nm half-pitch, it is crucial for the future of EUVL to show its
extendibility towards further technology nodes. In the last years, the EUV interference lithography tool at Paul Scherrer
Institute, with its high-resolution and well-defined areal image, has been successfully employed for resist performance
testing. In this paper, we present performance (dose, CD, LER) of a chemically-amplified resist for a range of 16 nm to
30 nm HP. Cross-sectional SEM images of the patterns are presented providing valuable insight into the resist's
performance and failure mode. The reproducibility of our experiments are presented by repeating the same exposures
with constant process conditions over the course of several months, demonstrating the excellent stability of the tool as
well as the long shelf-life of our baseline resist. In addition, a comparative study of performance (dose, CD, LER) of
different inorganic resists is provided. Patterns of 16 nm and 10 nm HPs are demonstrated with an EUV CAR and
inorganic resists, respectively. Moreover, initial results of patterning with 6.5 nm wavelength are presented.

Evaluation of resist performance with EUV interference lithography for sub-22-nm patterning

We fabricate computer generated holograms for the generation of phase singularities at extreme ultraviolet (EUV) wavelengths using electron beam lithography and demonstrate their ability to generate optical vortices in the nonzero diffraction orders. To this end, we observe the characteristic intensity distribution of the vortex beam and verify the helical phase structure interferometrically. The presented method forms the basis for further studies on singular light fields in the EUV frequency range, i.e., in EUV interference lithography. Since the method is purely achromatic, it may also find applications in various fields of x ray optics.

Generation of extreme ultraviolet vortex beams using computer generated holograms.

We demonstrate the fabrication and analysis of well-ordered high-resolution quasiperiodic nanostructures with feature sizes down to a few tens of nanometers using extreme ultraviolet interference lithography. A well-controlled mask manufacturing process for producing high quality transmission diffraction masks enables simple and fast fabrication of highly ordered 2D quasiperiodic structures using 5- and 8-beam interference setups.

https://iopscience.iop.org/article/10.1088/0957-4484/23/10/105303/pdf

Fabrication of quasiperiodic nanostructures with EUV interference lithography.

High-resolution kagome lattice structures with feature sizes down to the sub-50 nm regime are fabricated using diffraction-based extreme ultraviolet interference lithography. The resulting interference pattern of multiple beams is sensitive to the relative phase of the interfering beams. The precise control of their phases is achieved by precise positioning of transmission diffraction gratings on a mask using a high-end electron beam lithography tool. The presented method may find applications in providing high-resolution and large-area kagome lattice structures for studies on frustrated magnetic systems, photonic crystals, and plasmonics.

/pdf/generation-of-high-resolution-kagome-lattice-structures-3z297m5g5y.pdf

Bernd Terhalle

Papers

Three-dimensional optically induced reconfigurable photorefractive nonlinear photonic lattices

Evaluation of resist performance with EUV interference lithography for sub-22-nm patterning

Generation of extreme ultraviolet vortex beams using computer generated holograms.

Fabrication of quasiperiodic nanostructures with EUV interference lithography.

Generation of high-resolution kagome lattice structures using extreme ultraviolet interference lithography