TY - CHAP A1 - Friedrich, Daniel A1 - Michling, Marcel A1 - Klocek, Jolanta A1 - Schmeißer, Dieter A1 - Avdoshenko, Stas A1 - Chumakov, Dmytro A1 - Zschech, Ehrenfried T1 - Study of C60 based films formation by NEXAFS T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44 N2 - The C60 fullerenes and some of its -OH, -CF3 and -Cl derivates are candidates for application as ultra-low-k insulators in the semiconductor industry. Future preparation of thin films based on these materials requires the stability of the substituted fullerenes against chemical handling and processing steps. The latter issue was addressed by our NEXAFS studies that were done by synchrotron radiation at the beam line U49/2-PGM2 at BESSY II. Performed were the C K-edge NEXAFS studies in total fluorescence and total electron yield modes. The C60 based films were deposited on silicon by spraying from solutions. The influence of the different substitutional groups with C60 molecules was studied. The data were compared to the reference spectra of a pure C60 film. For C60(OH)24, C60-Cl2 and C60(CF3)12 a variance of the intensity of the π*-resonance as well as shift to higher energies of 0.5 eV (-OH), 0.6 eV (-F), 0.7 eV (-Cl) were observed. The results confirm the necessary stability of the used C60 derivatives and shall be used for optimization of the film deposition chemistry and conditions. Y1 - 2009 SN - 0420-0195 SP - S. 145 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Michling, Marcel A1 - Friedrich, Daniel A1 - Schmeißer, Dieter A1 - Koval, Yuri A1 - Müller, Paul T1 - Study of polyimide after graphitization with low-energy Ar+ Ion irradiation by NEXAFS T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44 N2 - In this contribution we report on investigations of the electronic structure of Ar+ irradiated polyimide samples by using NEXAFS. The NEXAFS measurements were done at the U49/2-PGM2 beam line of BESSY II, Berlin using TEY and TFY detection. Polyimide samples are prepared using low Ar+ dose while the temperature of the samples is varied between 300K and 700K. In the NEXAFS data at the Carbon K-edge we see substantial changes between different samples. The differences appear in particular in the more surface sensitive TEY-Signal. The NEXFS data are consistent with the graphitization of the surface upon Ar+ bombardment as we identify the characteristic absorption bands of graphitic carbon. Its relative content increases with increasing sample temperature. In contrast, in the more bulk sensitive TFY data, the emission characteristic of polyimide is maintained. The possibility to cover insulating polymers with a conducting layer is a great demand for many applications. Because of the relative low price of the basic materials, the irradiation with low-energy Ions will play an important roll in the microelectronic of the future. Y1 - 2009 UR - http://www.dpg-verhandlungen.de/year/2009/conference/dresden/part/df/session/15/contribution/5 SN - 0420-0195 SP - S. 147 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Friedrich, Daniel A1 - Michling, Marcel A1 - Schmeißer, Dieter A1 - Koval, Yuri A1 - Müller, Paul T1 - Characterization of ion beam modified polyimide layers T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45 N2 - Ion beam modified polyimide show high conductivity. In our investigation we focus on the electronic structure and the element composition, in order to understand the mechanism of conductivity. In our experiments we use the methods NEXAFS and PES. The measurements were done at the U49/2-PGM2 beam line of BESSY II, Berlin. We find an increase of the sp2 hybridized graphite contribution, after low Ar+ ion doses bombardment while the temperature of the samples is varied from 300 K to 650 K. In addition we follow the He+ bombardment induced changes by in-situ monitoring of the O1s, N1s content in the polyimide films. Y1 - 2010 UR - http://www.dpg-verhandlungen.de/year/2010/conference/regensburg/part/ds/session/38/contribution/10 SN - 0420-0195 SP - S. 247 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Michling, Marcel A1 - Kolanek, Krzysztof A1 - Schmeißer, Dieter A1 - Tallarida, Massimo T1 - A growth model for the HfO2 ALD process T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46 N2 - In this contribution we report on our in-situ2 cycle-by-cycle (up to the 25 cycles) investigation of the HfO2 atomic layer deposition (ALD) process using the method of x-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS). We used Tetrakis-Dimethyl-Amino-Hafnium (TDMA-Hf) and H2O as precursors and p-type Si wafer with native oxide as a substrate. The XPS measurements were carried out at BESSY II in Berlin with primary energies of 150 eV and 640 eV and the EELS measurements were done with a primary energy of 50 eV. We measured the O1s, Si2p core level and the valence band including the Hf 4f core level. From the Hf4f to Si2p ratios taken at each energy we developed a growth model for the first monolayer and for the following layers too. From our data we conclude, that in the first monolayer up to the fourth ALD cycle an island growth occurs. The height of these islands is about 0,5nm. After the first monolayer is completed, a layer- by-layer growth can be expected. In order to proof this observation we have simulated the Hf/Si ratio for different excitation energies and found a very good agreement with our measurement data. The EELS data especially the evaluation of the loss function onset confirm our growth model. Y1 - 2011 UR - http://www.dpg-verhandlungen.de/year/2011/conference/dresden/part/ds/session/12/contribution/1 SN - 0420-0195 SP - S. 294 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Tallarida, Massimo A1 - Deßmann, Nils A1 - Städter, Matthias A1 - Friedrich, Daniel A1 - Michling, Marcel A1 - Schmeißer, Dieter T1 - Atomic layer deposition of TiO T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46 N2 - We present a study of the initial growth of TiO2 on Si(111) by atomic layer deposition (ALD). The Si substrate was etched with NH4F before ALD to remove the native oxide film and to produce a Si-H termination. In−situ experiments by means of photoemission and X-ray absorption spectroscopy were conducted with synchrotron radiation on Ti-oxide films produced using Ti-tetra-iso-propoxide (TTIP) and water as precursors. O1s, Ti2p, C1s, and Si2p core level, and O1s and Ti2p absorption edges show the transition of the Ti-oxide properties during the first layers. The growth starts with a very small growth rate (0.03nm/cycle) due to the growth inhibition of the Si-H termination and proceeds with higher growth rate (0.1nm/cycle) after 1.5nm Ti-oxide has been deposited. Y1 - 2011 UR - http://www.dpg-verhandlungen.de/year/2011/conference/dresden/part/ds/session/12/contribution/2 SN - 0420-0195 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Tallarida, Massimo A1 - Michling, Marcel A1 - Das, Chittaranjan A1 - Friedrich, Daniel A1 - Städter, Matthias A1 - Schmeißer, Dieter T1 - Role of substrate chemistry in ALD revealed by in-situ techniques T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47 N2 - We show recent results of our in-situ investigations where the role of substrate chemistry in ALD is outlined. While the usual strategy to develop new properties of ALD films is to find new precursors or new procedures, the influence of substrate chemistry on the growth properties of ALD films has been often underestimated. This has principally a technical reason, as the usual characterization methods (QMS, FTIR, ellipsometry) are only weakly sensitive to the substrate, and a characterization of substrates before ALD is often not possible. Thanks to the use of in-situ characterization methods, including photoemission and X-ray absorption spectroscopy with synchrotron radiation, we are able to determine chemical properties of substrates before ALD and after either half or complete ALD cycles. The substrate chemistry influences the standard Al2O3 ALD with TMA and water [1,2], as well as the TiO2 ALD with TTIP and either water, O2 or O2-plasma. [1] M. Tallarida, K. Kukli, M. Michling, M. Ritala, M. Leskelä and D. Schmeisser, Chem. Mater. 23, 3159 (2011); [2] M. Tallarida, C. Adelmann, A. Delabie, S. van Elshocht, M. Caymax, and D. Schmeisser, Appl. Phys. Lett. 92, 042906 (2011). Y1 - 2012 UR - http://www.dpg-verhandlungen.de/year/2012/conference/berlin/part/ds/session/22/contribution/3 SN - 0420-0195 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER -