Design and modeling of non-uniformly doped deep-submicron pocket MOSFETs for low-voltage low-power applications
AuthorPang, Yon Sup
AdvisorBrews, John R.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractLaterally non-uniformly doped 0.1-μm pocket n-MOSFETs satisfying specifications of off-state current, on-state current, sensitivity of off-state current to channel length and 1V power-supply voltage have been designed for low-voltage low-power applications. To determine a viable range of the deep-submicron pocket n-MOSFET structural parameters---the dopant concentration at the center region (Nc), the dopant concentration at the pocket region (Np) and the length of the pocket region (Lp), a unique viable design space locating the deep-submicron devices meeting all the device specifications have been constructed, using computer algorithms developed and implemented in the programming language of the two-dimensional device simulator, Medici. For known Nc, vs. Lp, the pocket n-MOSFETs for low-power applications are located in an upper area of higher Np vs. Lp of the viable design space while the devices for high-performance applications are located in a lower area of lower Np vs. Lp of the viable design space. Well-designed deep-submicron pocket n-MOSFETs prove to be promising candidates to improve short-channel effects as well as switching performance in comparing the 0.1-μm pocket n-MOSFETs located within the viable design space to 0.1-μm conventional bulk n-MOSFETs selected to meet the same specifications. The 0.1-μm pocket n-MOSFETs located within the viable design space can be partitioned into two types of pocket devices based on gate controllability of channel- and depletion-layer charges. Analytical models for subthreshold and above-threshold currents in the deep-submicron pocket n-MOSFETs have been developed for the first time to generate the off-state and the on-state currents, and the design-space boundaries for the on- and the off-state currents. The models are based on solutions of the drift-diffusion current transport and the 1-D Poisson's equations, the charge sheet approximation, subthreshold surface potential models based on solutions of the quasi-two-dimensional Poisson's equation, a quasi-two-dimensional velocity saturation model, realistic mobility models, and analytical formulas for model parameters. The analytical models provide explicit relations between process, device and model parameters of the deep-submicron pocket n-MOSFETs, and reduce time and cost of the two-dimensional device simulation. Some algorithms developed for generating ID - V DS characteristics and constructing the design-space boundaries are described.
Degree ProgramGraduate College
Electrical and Computer Engineering