Effiziente Multisubband-Bauelementsimulation von nanometrischen Feldeffekttransistoren unter Berücksichtigung von hoch permitiven Dielektrika und III-V Halbleitern
Zusammenfassung der Projektergebnisse
The main project goal is to support the development of new MOS devices by reliable device simulations. In order to achieve this goal the work was splitted into two part, the investigation of numerical simulation methods for n- and p-MOSFETs. In case of p-MOSFETs a proved and tested self-consistent and deterministic solver of 6 × 6 k·p Schrödinger equation, multi subband Boltzmann transport equations and Poisson equation was enhanced such that nanoscale p-FETs with high-κ gate dielectrics and with strained III-V channel materials can be simulated in a predictive manner. For Ti/HfO2 /SiO2 gate stacks it is shown that the mobility degradation caused by remote Coulomb scattering and the related flatband voltage shift, which are both due to the dipole layer at the interface between the different oxides, can be modeled consistently without any gate stack related parameter adjustment. Polar optical scattering can now be considered in the simulations of III-V hole transport. The simulation of biaxially strained GaSb double gate p-MOSFETs was demonstrated and compared to other state of the art modeling results available in the literature. This comparison indicates that more research in this field is needed in order to establish a more reliable model parameter base for p-FET simulation with III-V channel materials. A fully self-consistent and deterministic solver of Poisson, Schrödinger, and Boltzmann equations for nanoscale n-MOSFETs was developed. New stability enhancing methods enabled the formulation of a full Newton-Raphson approach that includes all interdependencies of the three equations and that is numerically stable and converges quadratically. Significant obstacles for the implementation of a deterministic computation of small-signal and noise parameters were cleared. Thus, the first ever self-consistent deterministic solver for the small-signal and noise characterization of nanoscale n-MOSFETs was reported in this project. In addition the n-FET simulator has been extended to III-V materials using a general isotropic band structure and considering polar optical phonon scattering. The deterministic approach for terminal current, small-signal and noise characterization of nanoscale MOSFETs is superior to the common Monte-Carlo based approaches due to the efficient formulation of self-consistency and due to the inherent advantages of deterministic solvers over stochastic and transient solvers.
Projektbezogene Publikationen (Auswahl)
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“A self-consistent solution of the Poisson, Schrödinger and Boltzmann equations by a full Newton-Raphson approach for nanoscale semiconductor devices,” in Simulation of Semiconductor Processes and Devices (SIS-PAD), 2013 International Conference on ..., Sept 2013, pp. 356–359
D. Ruić and C. Jungemann
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“On the modeling of Coulomb scattering in p-MOSFETs with hafnium based metal gate stacks,” in Proc. ULIS, 2014, pp. 113–116
A. Kuligk and B. Meinerzhagen
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“A Self-consistent Solution of the Poisson, Schrödinger and Boltzmann Equations for GaAs Devices by a Deterministic Solver,” in Simulation of Semiconductor Processes and Devices (SISPAD), 2015 International Conference on ...; IEEE, 2015, pp. 361–364
Z. Kargar, D. Ruić, and C. Jungemann
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“Numerical aspects of noise simulation in MOSFETs by a Langevin-Boltzmann solver,” Journal of Computational Electronics, vol. 14, no. 1, pp. 21–36, 2015
D. Ruić and C. Jungemann
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“On the modeling of Coulomb scattering in p-MOSFETs with hafnium based metal gate stacks,” Solid–State Electron., vol. 108, pp. 84–89, 2015
A. Kuligk and B. Meinerzhagen
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“Small Signal and Microscopic Noise Simulation of an nMOSFET by a Self-Consistent, Semi-Classical and Deterministic Approach,” in Simulation of Semiconductor Processes and Devices (SISPAD), 2015 International Conference on ...; IEEE, Sept 2015, pp. 20–23
D. Ruić and C. Jungemann
