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Suche nach „[T.] [Blomberg]“ hat 9 Publikationen gefunden
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    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    Günther Ruhl, W. Lehnert, M. Lukosius, C. Wenger, C. Baristiran Kaynak, T. Blomberg, S. Haukkac, P. Baumann, W. Besling, A. Roeste, B. Riou, S. Lhostif, A. Halimaou, F. Roozeboom, E. Langereis, W.M.M. Kessels, A. Zauner, S. Rushworth

    Dielectric Material Options for Integrated Capacitors

    ECS Journal of Solid State Science and Technology, vol. 3, no. 8

    2014

    DOI: 10.1149/2.0101408jss

    Abstract anzeigen

    Future MIM capacitor generations will require significantly increased specific capacitances by utilization of high-k dielectric materials. In order to achieve high capacitance per chip area, these dielectrics have to be deposited in three-dimensional capacitor structures by ALD or AVD (atomic vapor deposition) process techniques. In this study eight dielectric materials, which can be deposited by these techniques and exhibit the potential to reach k-values of over 50 were identified, prepared and characterized as single films and stacked film systems. To primarily focus on a material comparison, preliminary processes were used for film deposition on planar test devices. Measuring leakage current density versus the dielectric constant k shows that at low voltages (≤1 V) dielectrics with k-values up to 100 satisfy the typical leakage current density specification of <10−7 A/cm2 for MIM capacitors. At higher voltages (3 V) this specification is only fulfilled for dielectrics with k-values below 45. As a consequence, the maximum achievable capacitance gain by introducing high-k dielectrics depends on the operating voltage of the application, such as DRAM capacitors or RF and blocking capacitors. To meet the reliability requirements for RF and blocking capacitors, high-k dielectric film thicknesses of up to 50 nm are necessary.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    M. Lukosius, C. Wenger, T. Blomberg, Günther Ruhl

    Properties of stacked SrTiO3/Al2O3 metal–insulator–metal capacitors

    Journal of Vacuum Science & Technology B, vol. 31, no. 1

    2013

    DOI: 10.1116/1.4766183

    Abstract anzeigen

    The possibilities to grow thin films of SrTiO3 and Al2O3 by atomic layer deposition for stacked metal–insulator–metal capacitors have been investigated in this work. In order to tune the functional properties of the capacitors, different processing steps have been employed to realize different combinations of the dielectric stacks. Electrical properties, extracted after the postdeposition annealing and sputter deposition of the Au top electrodes, indicated that the metal–insulator–metal (MIM) structures with additional Al2O3 layer provided better leakage currents densities, compared to the ones with single SrTiO3 based MIM capacitors, but the dielectric constant values have also decreased if additional Al2O3 film was inserted. Attempts to optimize the properties of the MIM stacks have been done by manufacturing heterostructures of Al2O3/SrTiO3/Al2O3 as well as SrTiO3/Al2O3/SrTiO3. In the first case, Al2O3 prevented the crystallization of SrTiO3 in the multilayer dielectric structure and therefore reduced the total capacitance density of the particular MIM stack, whereas the SrTiO3/Al2O3/SrTiO3 stack was found to possess superior electrical properties. Leakage current density as low as ∼10−8 A/cm2 at 2 V and the dielectric constant value of 40 have been extracted.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    M. Lukosius, T. Blomberg, D. Walcyk, Günther Ruhl, C. Wenger

    Metal-Insulator-Metal capacitors with ALD grown SrTiO3: Influence of Pt electrodes

    IOP Conference Series: Materials Science and Engineering, vol. 41

    2012

    Abstract anzeigen

    Metal-Insulator-metal (MIM) capacitors with atomic layer deposited (ALD) single SrTiO3 dielectric have been investigated in this work. Structural and electrical properties were studied after the formation of the MIM stack consisting of the platinum (Pt) bottom electrode, 50 nm SrTiO3 layer and the top Pt electrode. The as deposited films were amorphous and had a dielectric constant of ~ 10, whereas the annealing of the samples in the nitrogen (N2) or oxygen (O2) atmosphere at 550-600 °C led to the crystallization of the SrTiO3 and therefore to the increased dielectric constant of ~ 85. In addition, the electrical results revealed that the combination of SrTiO3 with the high work function electrode like Pt, provided better leakage current performance in comparison with TiN/ SrTiO3 stacks. The values as low as ~ 10−7 A/cm2 at 2 V were observed for both in N2 or O2 annealed SrTiO3 layers. On the other hand, the samples annealed in O2 atmosphere at 600 °C possessed lower capacitance-voltage nonlinearity coefficients (−645 ppm/V2) than the ones for N2 annealed samples (-2700 ppm/V2).

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    M. Lukosius, C. Wenger, T. Blomberg, A. Abrutis, G. Lupina, P. Baumann, Günther Ruhl

    Electrical and Morphological Properties of ALD and AVD Grown Perovskite-Type Dielectrics and Their Stacks for Metal-Insulator-Metal Applications

    ECS Journal of Solid State Science and Technology, vol. 1, no. 1

    2012

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    M. Lukosius, C. Baristiran Kaynak, S. Kubotsch, T. Blomberg, Günther Ruhl, C. Wenger

    Properties of atomic-vapor and atomic-layer deposited Sr, Ti, and Nb doped Ta2O5 Metal–Insulator–Metal capacitors

    Thin Solid Films, vol. 520, no. 14, pp. 4576-4579

    2012

    DOI: 10.1016/j.tsf.2011.10.199

    Abstract anzeigen

    Atomic Vapor Deposition and Atomic Layer Deposition techniques were applied for the depositions of Ta2O5, Ti–Ta–O, Sr–Ta–O and Nb–Ta–O oxide films for Metal–Insulator–Metal (MIM) capacitors used in back-end of line for Radio Frequency applications. Structural and electrical properties were studied. Films, deposited on the TiN bottom electrodes, in the temperature range of 225–400 °C, were amorphous, whereas the post deposition annealing at 600 °C resulted in the crystallization of Nb–Ta–O films. Electrical properties of MIM structures, investigated after sputtering Au top electrodes, revealed that the main characteristics were different for each oxide. On one hand, Ti–Ta–O based MIM capacitors possessed the highest dielectric constant (50), but the leakages currents were also the highest (~ 10− 5 A/cm2 at − 2 V). On the other hand, Sr–Ta–O showed the lowest leakage current densities (~ 10− 9 A/cm2 at − 2 V) as well as the smallest capacitance–voltage nonlinearity coefficients (40 ppm/V2), but the dielectric constant was the smallest (20). The highest nonlinearity coefficients (290 ppm/V2) were observed for Nb–Ta–O based MIM capacitors, although relatively high dielectric constant (40) and low leakage currents (~ 10− 7 A/cm2 at − 2 V) were measured. Temperature dependent leakage-voltage measurements revealed that only Sr–Ta–O showed no dependence of leakage current as a function of the measurement temperature.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    C. Wenger, M. Lukosius, T. Blomberg, A. Abrutis, P. Baumann, Günther Ruhl

    ALD and AVD Grown Perovskite-type Dielectrics for Metal-Insulator-Metal Application

    (Invited)

    ECS Transactions, vol. 41, no. 2, pp. 53-61

    2011

    DOI: 10.1149/1.3633654

    Abstract anzeigen

    Atomic Vapor Deposition (AVD) and Atomic Layer Deposition (ALD) techniques were successfully applied for the depositions of perovskite type dielectrics, namely, Sr-Ta-O, Ti-Ta-O, Sr-Ti-O, Ba-Hf-O, Nb-Ta-O and Ce-Al-O. Thin films were investigated as alternative dielectrics for Metal-Insulator-Insulator (MIM) capacitors. Structural and electrical properties are investigated after depositing the metal oxides on 200 mm TiN/Si (100) substrates within the temperature range of 225-400 ºC. Electrical properties, investigated after sputtering Au top electrodes, revealed that the main characteristics are different for each dielectric. The highest dielectric constants were achieved for crystalline SrTiO3 (k=95), crystalline CeAlO3 (k = 60) and amorphous Ti-Ta-O (k = 50) films. However, Sr-Ta-O based MIM capacitors showed the lowest leakage current densities as well as the smallest capacitancevoltage linearity coefficients.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    T. Blomberg, C. Wenger, C. Baristiran Kaynak, Günther Ruhl, P. Baumann

    ALD grown NbTaOx based MIM capacitors

    Microelectronic Engineering, vol. 88, no. 8, pp. 2447-2451

    2011

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    C. Baristiran Kaynak, M. Lukosius, B. Tillack, C. Wenger, T. Blomberg, Günther Ruhl

    Single SrTiO3 and Al2O3/SrTiO3/Al2O3 based MIM capacitors: Impact of the bottom electrode material

    Microelectronic Engineering, vol. 88, no. 7, pp. 1521-1524

    2011

    DOI: 10.1016/j.mee.2011.03.022

    Abstract anzeigen

    Metal–Insulator–Metal (MIM) capacitors with atomic layer deposited (ALD) single SrTiO3 dielectric and Al2O3/SrTiO3/Al2O3 multilayer dielectric have been deposited on TaN and TiN bottom electrodes. The MIM stacks have been analyzed and compared in terms of electrical and structural properties. The results indicate that MIMs with multilayer dielectrics provide better leakage current performance than the ones with single dielectrics while capacitance density is decreased. Additional Al2O3 layers prevented the crystallization of SrTiO3 in the multilayer dielectric stack. The decreased capacitance density in MIMs with multilayer dielectric is attributed to the amorphous structure of SrTiO3 and the series capacitance of top and bottom Al2O3 layers. Furthermore, MIM capacitors with single SrTiO3 dielectric layer on TiN electrodes indicated better capacitance density compared to the one with TaN electrodes. The lower capacitance density of the single SrTiO3 dielectric on TaN electrodes is correlated to the interfacial layer formation between SrTiO3 and TaN electrodes.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    C. Baristiran Kaynak, M. Lukosius, I. Costina, B. Tillack, C. Wenger, Günther Ruhl, T. Blomberg

    Enhanced leakage current behavior of Sr2Ta2O7-x/SrTiO3 bilayer dielectrics for metal-insulator-metal capacitors

    Thin Solid Films, vol. 519, no. 17, pp. 5734-5739

    2011

    DOI: 10.1016/j.tsf.2011.01.001

    Abstract anzeigen

    Metal–Insulator–Metal (MIM) capacitors are one of the most essential components of radio frequency devices and analog/mixed-signal integrated circuits. In order to obtain high capacitance densities in MIM devices, high-k materials have been considered to be promising candidates to replace the traditional insulators. The challenging point is that the dielectric material must demonstrate high capacitance density values with low leakage current densities. In this work, SrTiO3 based MIM capacitors have been investigated and the electrical performance of the devices have been optimized by using bilayered systems of Sr2Ta2O7−x/SrTiO3 with different thicknesses of Sr2Ta2O7−x. Sputtering X-Ray photoelectron spectroscopy (XPS) measurements have been applied to investigate the interfaces between the thin film constituents of the MIM stacks. The optimized bilayered system provides a leakage current density of 8∗10− 8 A/cm2 at 2 V (bottom electrode injection) and a high capacitance density of 13 fF/μm2.