@inproceedings{GeislerBauerHaaketal.2008, author = {Geisler, Sebastian and Bauer, Joachim and Haak, Ulrich and Stolarek, David and Schulz, K. and Wolf, H. and Meier, W. and Trojahn, M. and Matthus, E. and Beyer, Harald and Old, G. and Marschmeyer, Steffen and Kuck, B.}, title = {Double exposure technology for KrF lithography}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15176}, pages = {65 -- 73}, year = {2008}, abstract = {The application of Double Exposure Lithography (DEL) would enlarge the capability of 248 nm exposure technique to smaller pitch. We will use the DEL for the integration of critical layers for dedicated applications requiring resolution enhancement into 0.13 μm BiCMOS technology. In this paper we present the overlay precision and the focus difference of 1st and 2nd exposure as critical parameters of the DEL for k1 ≤ 0.3 lithography (100 nm half pitch) with binary masks (BIM). The realization of excellent overlay (OVL) accuracy is a main key of double exposure and double patterning techniques. We show the DEL requires primarily a good mask registration, when the wafer stays in the scanner for both exposures without alignment between 1st and 2nd exposure. The exposure tool overlay error is more a practical limit for double patterning lithography (DPL). Hence we prefer the DEL for the resolution enhancement, especially if we use the KrF high NA lithography tool for 130 nm generation. Experimental and simulated results show that the critical dimension uniformity (CDU) depends strongly on the overlay precision. The DEL results show CDU is not only affected by the OVL but also by an optical proximity effect of 1st and 2nd exposure and the mask registration. The CD uniformity of DEL demands a low focus difference between 1st and 2nd exposure and therefore requires a good focus repeatability of the exposure tool. The Depth of Focus (DOF) of 490 nm at stable CD of lines was achieved for DEL. If we change the focus of one of the exposures the CD-focus performance of spaces was reduced with simultaneous line position changing. CDU vs. focus difference between 1st and 2nd exposure demands a focus repeatability <100 nm for the exposure tool. Summary, the results show DEL has the potential to be a practical lithography enhancement method for device fabrication using high NA KrF tool generation.}, language = {en} } @inproceedings{SteglichMaiStolareketal.2016, author = {Steglich, Patrick and Mai, Christian and Stolarek, David and Lischke, Stefan and Kupijai, Sebastian and Villringer, Claus and Pulwer, Silvio and Heinrich, Friedhelm and Bauer, Joachim and Meister, Stefan and Knoll, Dieter and Casalboni, Mauro and Schrader, Sigurd}, title = {Partially slotted silicon ring resonator covered with electro-optical polymer}, series = {Proceedings of SPIE}, booktitle = {Proceedings of SPIE}, issn = {1996-756X}, doi = {10.1117/12.2217725}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13771}, year = {2016}, abstract = {In this work, we present for the first time a partially slotted silicon ring resonator (PSRR) covered with an electro-optical polymer (Poly[(methyl methacrylate)-co-(Disperse Red 1 acrylate)]). The PSRR takes advantage of both a highly efficient vertical slot waveguide based phase shifter and a low loss strip waveguide in a single ring. The device is realized on 200 mm silicon-on-insulator wafers using 248 nm DUV lithography and covered with the electro-optic polymer in a post process. This silicon-organic hybrid ring resonator has a small footprint, high optical quality factor, and high DC device tunability. A quality factor of up to 105 and a DC device tunability of about 700 pm/V is experimentally demonstrated in the wavelength range of 1540 nm to 1590 nm. Further, we compare our results with state-of-the-art silicon-organic hybrid devices by determining the poling efficiency. It is demonstrated that the active PSRR is a promising candidate for efficient optical switches and tunable filters.}, language = {en} } @inproceedings{MeisterAlSaadiFrankeetal.2011, author = {Meister, Stefan and Al-Saadi, Aws and Franke, B{\"u}lent A. and Mahdi, Shaimaa and Szczambura, Miroslaw and Kuhlow, Berndt and Woggon, Ulrike and Zimmermann, Lars and Richter, Harald H. and Stolarek, David and Schrader, Sigurd and Eichler, Hans J.}, title = {Micro-cavities based on width modulated SOI waveguides}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15233}, pages = {199 -- 204}, year = {2011}, abstract = {We have designed, fabricated and investigated one-dimensional (1D) micro-cavities in Silicon-on-Insulator (SOI) waveguides. The single mode waveguides are fabricated in a 220 nm silicon device layer. The 1D micro-cavities in Fabry-Perot structure consist of two Bragg-mirror regions formed by a sinusoidal modulation of the waveguide width. The mirror regions are separated by a sub-micron spacer. The SOI photonic structures are produced in a CMOS environment using 248 nm DUV lithography. The waveguides as well as the width modulated mirror regions are designed using a single mask and are fabricated in a shallow trench process. The transmission spectra of these width modulated micro-cavities with different mirror reflectivities and cavity lengths are investigated. Q-factors up to 855 could be observed at 1550 nm wavelength with low insertion loss of 1.9 dB. The width modulated micro-cavities, including the mirror regions, have lengths of less than 20 microns and widths of maximum 450 nm. These small foot-print cavities act as band pass filters and can be used as resonators for laser or electro-optic modulation of light.}, language = {en} } @inproceedings{WangMeisterMahdietal.2011, author = {Wang, Sha and Meister, Stefan and Mahdi, Shaimaa and Franke, B{\"u}lent A. and Al-Saadi, Aws and Zimmermann, Lars and Richter, Harald H. and Stolarek, David and Lisinetskii, Viktor and Ksianzou, Viachaslau and Schrader, Sigurd and Eichler, Hans J.}, title = {Spontaneous and stimulated Raman scattering in planar silicon waveguides}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15248}, pages = {281 -- 289}, year = {2011}, abstract = {Raman scattering in planar silicon on insulator (SOI) waveguides with 2 μm width, 220 nm height and 2 cm length is investigated. A cw Nd:YAP laser at 1340.6 nm with 7 GHz FWHM spectral width is used as the pump source. A lensed fiber of 2.5 μm focus diameter is used to couple the pump laser into the waveguide. The coupling efficiency is estimated to be around 10\%. Spontaneous Raman scattering is observed with as low as 2.5 mW pump power inside the waveguide. The spontaneous Raman spectrum is measured by an optical spectrum analyzer. The first order Raman peak is measured at around 1441.4 nm corresponding to a Raman shift of 15.6 THz, while the FWHM of Raman spectrum is measured as around 100 GHz. Maximum Raman output of around 90 pW is obtained by around 22 mW pump. The stimulated Raman gain coefficient is estimated as around 56 cm/GW from the relationship between spontaneous Raman output power and pump power. A temperature dependence of Raman frequency shift of about 0.6 GHz/K is measured. The spontaneous anti-Stokes Raman scattering output peak at 1253 nm is also observed with around 35 mW pump. Stimulated Raman amplification measurement is carried out with a SLED white light source as probe signal. With 35 mW pump power, around 0.6 dB gain has been determined with both pump and probe being TE polarized.}, language = {en} } @inproceedings{GeislerBauerHaaketal.2008, author = {Geisler, Sebastian and Bauer, Joachim and Haak, Ulrich and Stolarek, David and Schulz, K. and Wolf, H. and Meier, W. and Trojahn, M. and Matthus, E.}, title = {100 nm half-pitch double exposure KrF lithography using binary masks}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15169}, pages = {698 -- 705}, year = {2008}, abstract = {In this paper we investigate the process margin for the 100nm half - pitch double exposure KrF lithography using binary masks for different illumination settings. The application of Double Exposure Lithography (DEL) would enlarge the capability of 248 nm exposure technique to smaller pitch e.g. for the integration of dedicated layers into 0.13 μm BiCMOS with critical dimension (CD) requirements exceeding the standard 248 nm lithography specification. The DEL was carried out with a KrF Scanner (Nikon S207D, NALens = 0.82) for a critical dimension (CD) of 100nm half pitch. The chemical amplified positive resists SL4800 or UV2000 (Rohm \& Haas) with a thickness of 325nm were coated on a 70 nm AR10L (Rohm \& Haas) bottom anti-reflective coating (BARC). With a single exposure and using binary masks it is not possible to resolve 100nm lines with a pitch of 200 nm, due to the refraction and the resolution limit. First we investigated the effect of focus variation. It is shown that the focus difference of 1st and 2nd exposure is one critical parameter of the DEL. This requires a good focus repeatability of the scanner. The depth of focus (DOF) of 360 nm with the coherence parameter σ = 0.4 was achieved for DEL with SL4800 resist. The influence of the better resist resolution of UV2000 on the process window will be shown (DOF = 460 nm). If we change the focus of one of the exposures the CD and DOF performance of spaces is reduced with simultaneous line position changing. Second we investigated the effect of different illumination shapes and settings. The results for conventional illumination with different values for σ and annular illumination with σinner = 0.57 and σouter = 0.85 will be shown. In summary, the results show that DEL has the potential to be a practical lithography enhancement method for device fabrication using high NA KrF tool generation.}, language = {en} }