Engenharia Elétrica
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/21
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3 resultados
Resultados da Pesquisa
- Analytical model for the threshold voltage in junctionless nanowire transistors of different geometries(2011-09-02) TREVISOLI, R. D.; Rodrigo Doria; Marcelo Antonio PavanelloJunctionless nanowire transistors (JNTs) are considered promising for the sub-20 nm era. As these devices have a constant doping profile from source to drain, they have a great scalability without the need for rigorously controlled doping and activation techniques. These devices also present a flexible threshold voltage, which strongly depends on the device cross section. This work proposes an analytical model for JNTs. The model is derived from the solution of the Poisson equation with the appropriate boundary conditions. The quantum confinement for devices of reduced dimensions has also been accounted. The threshold voltage in cylindrical and trigate JNTs are analyzed. Tridimensional numerical simulations were performed to validate the model. ©The Electrochemical Society.
- Accounting for short channel effects in the drain current modeling of junctionless nanowire transistors(2012-09-02) TREVISOLI, R. D.; Rodrido Doria; Michelly De Souza; Marcelo Antonio PavanelloJunctionless nanowire transistors have a constant doping profile from source to drain, providing a great scalability without the need of rigorously controlled doping gradients and activation techniques. Therefore, these devices are considered as promising for decananometer era. This work proposes an analytical model for the drain current in junctionless nanowire transistor (JNT) accounting for short channel effects and temperature dependence. Tridimensional numerical simulations of p-type devices have been performed to validate the model. Experimental data of n-type devices have also been used. © The Electrochemical Society.
- Low-Frequency Noise of nMOS and pMOS short channel junctionless nanowire transistors(2012-10-04) Rodrido Doria; TREVISOLI, R. D.; Michelly De Souza; FERAIN, I.; DAS, S.; Marcelo Antonio PavanelloMulti-gate architecture has been considered as one of the most viable alternatives to MOS devices scaling below 22 nm nodes [1] due to its stronger robustness to the short channel effects with respect to planar architectures. In short channel devices, the control of the gate over the channel charges dramatically decreases making the use of planar devices extremely challenging. Despite providing an improved coupling between gates and channel, conventional inversion mode (IM) multi-gate structures such as Trigate and FinFETs present p-n junctions between source/drain and channel, which can become an important bottleneck for ultimate technologies in which the formation of ultra-sharp junctions is needed in order to avoid the source/drain dopants diffusion into the channel. A novel multi-gate architecture so-called Junctionless Nanowire Transistor (JNT) was recently developed to overcome this bottleneck [2-3]. The JNT consists of a silicon nanowire surrounded by gate stack and is different from multi-gate IM devices due to its doping profile which is heavy and constant between source, channel and drain without any dopant gradients. The longitudinal sections of both a pMOS and an nMOS JNT are shown in Fig. 1 where the p-type is doped with boron and the n-type ones with phosphorous. The silicon nanowire needs to have a square-section small enough to be fully depleted at low gate voltages, turning off the device. Above threshold, the current flows mainly due to bulk conduction [4]. Several papers have shown the potentiality of the JNT for technological nodes beyond 10 nm [2-6] since it provides better DIBL, subthreshold slope and analog properties than IM multi-gate transistors of similar dimensions [5,6]. Although the Low-Frequency Noise (LFN) of JNTs has been treated in different papers [7,8], only long devices have been evaluated up to now and in none of them the LFN of pMOS was addressed as proposed in the current paper. © 2012 IEEE.