Publikationen


Suche nach „[S.] [Rushworth]“ hat 4 Publikationen gefunden
Suchergebnis als PDF
    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

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

    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

    S. Rushworth, Günther Ruhl, M. Lukosius, P. Baumann, C. Wenger, C. Baristiran Kaynak

    Atomic Vapor Depositions of Ti–Ta–O thin films for Metal–Insulator–Metal applications

    Thin Solid Films, vol. 519, no. 11, pp. 3831-3834

    2011

    DOI: 10.1016/j.tsf.2011.01.239

    Abstract anzeigen

    Atomic Vapor Deposition technique was applied for the depositions of Ti–Ta–O oxide films for Metal–Insulator–Metal capacitors used in back-end of line for Radio Frequency applications. Composition, crystallinity, thermal stability and electrical properties were studied. Ti–Ta–O films, with the ratio of Ta/Ti ~ 1.5, deposited at 400 °C on TiN electrodes, were amorphous and possessed a dielectric constant of 50 with low voltage linearity coefficients and leakage currents densities as low as 10− 7 A/cm2 at 1 V. The films, deposited on Si wafers, were amorphous up to the annealing temperature of 700 °C and crystallized in orthorhombic Ta2O5 phase at higher temperatures.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    S. Rushworth, Günther Ruhl, M. Lukosius, C. Wenger, C. Baristiran Kaynak

    Electrical characteristics of Ti-Ta-O based MIM capacitors

    Journal of Vacuum Science & Technology B, vol. 29, no. 1

    2011

    DOI: 10.1116/1.3534020

    Abstract anzeigen

    Amorphous Ti–Ta–O thin films were deposited by the atomic-vapor deposition technique for metal-insulator-metal (MIM) applications. Depositions were carried out at 400 °C on 200-mm Si (100) wafers using TiN and TaN as bottom electrode materials. The comparison of electrical properties of MIM capacitors was done after physical-vapor deposited growth of different top electrodes, namely, Au, TiN, TaN, and Ti. Capacitance-voltage measurements revealed that the dielectric constant of 50 can be reached if Ti–Ta–O layers are deposited on TiN and if Au, TaN, or Ti is used as the top electrode. The k value is reduced to 37 if TaN is used as bottom electrode. However, if TiN is used as the top electrode, the k value of the stack is reduced by a factor of 3, from 50 to 17, independent of whether TiN or TaN are used as bottom electrodes. The lowest leakage current values (∼10−8 A/cm2) were observed when gold was used as the top electrode, whereas it increased by 3 orders of magnitude if the top electrode was changed to TiN and even more if the top electrode was changed to TaN or Ti.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau

    Zeitschriftenartikel

    S. Rushworth, Günther Ruhl, B. Tillack, I. Costina, M. Lukosius, C. Wenger, C. Baristiran Kaynak

    Investigations of thermal annealing effects on electrical and structural properties of SrTaO based MIM capacitor

    Microelectronic Engineering, vol. 87, no. 12, pp. 2561-2564

    2010

    DOI: 10.1016/j.mee.2010.07.015

    Abstract anzeigen

    The annealing effects on dielectric and electrode materials in Ti/SrTaO/TaN/TiN/Ti/Si metal–insulator–metal (MIM) capacitors were studied. The electrical and structural properties were investigated after subjecting the samples to annealing temperatures of 500 °C, 700 °C and 900 °C. The electrical results revealed that the dielectric constant (k value) of Sr–Ta–O increased from 18 to 50 with increasing annealing temperature. This improvement in k value can be associated to the crystallization of dielectric layer. However, the leakage current density increased several orders of magnitudes with increase of the annealing temperatures. This observation was attributed to crystallization of dielectric, degradation of TaN electrode and out-diffusion of Si from the substrate.