We demonstrate experimentally for the first time the feasibility of applying SMO technology using pixelated illumination. Wafer images of SRAM contact holes were obtained to confirm the feasibility of using SMO for 22nm node lithography. There are still challenges in other areas of SMO integration such as mask build, mask inspection and repair, process modeling, full chip design issues and pixelated illumination, which is the emphasis in this paper. In this first attempt we successfully designed a manufacturable pixelated source and had it fabricated and installed in an exposure tool. The printing result is satisfactory, although there are still some deviations of the wafer image from simulation prediction. Further experiment and modeling of the impact of errors in source design and manufacturing will proceed in more detail. We believe that by tightening all kind of specification and optimizing all procedures will make pixelated illumination a viable technology for 22nm or beyond.
Publisher's Note: The author listing for this paper has been updated to include Carsten Russ. The PDF has been updated to reflect this change.
The nonlinear optical response of carbon nanotubes (CNTs) to the interaction with intense ultrashort laser pulses was studied theoretically and experimentally. A full quantum-mechanical theory for harmonics generation from a single-walled CNT has been developed, using the quantum kinetic equations for π-electrons with both intraband and interband transitions taken into account. In the regime of strong driving fields, a non-perturbative approach with the numerical solution of the quantum kinetic equations in the time domain was used to calculate the density of the axial electric current in CNTs. The results of this theory are compared to experiments performed on samples of multi-walled CNTs, using pulses of 160 fs generated by a Cr:Forsterite laser, at a wavelength of 1250 nm. The experimental results show indeed an unusual nonperturbative behavior of the third-harmonic yield, for relatively low input laser fields of ~ 1010 W/cm2, in very good agreement with the theoretical predictions. The interaction of CNTs with strong laser fields results not only in the generation of harmonics, but also in the generation of a broad spectral background. Generation of a continuous background in the vicinity of the third-harmonic of the laser field was also obtained from the quantum-mechanical calculations, however, with lower intensities than observed experimentally. Possible explanations for this discrepancy will be discussed.