Simple approach to include external resistances in the Monte Carlo simulation of MESFETs and HEMTs

Abstract

narrower (Table I) so that the separation of energy sublevels along the y-direction is increased. This increases the oscillation period when measuring the conductances as functions of the Fermi energy. On the other hand, the increase of the Fermi energy as a function of the lower gate bias is very significant. In the final conductances versus lower gate bias diagram, Fig. 2, the Fermi energy factor dominates, and the oscillation period in the conductance increases, as indicated in the experiments when the upper gate bias is decreased.The calculated oscillation period increases with increasing lower gate bias in Fig. 2. This is due to the square-well approximation in the y-direction used in the model calculation. When parabolic well is used, the energy separations between sublevels are constant, so becomes the oscillation period. Thus, when real band profile is used in the transport calculation, constant oscillation period is expected. ( 3 )When Q = e and t = 13.1 (silicon), we have V = 1.1,'~ V at the surface of the sphere and 5' = 1.65/a V at the center (a is in the unit of A). It is shown that decreasing the upper gate bias makes the conducting channel created by the lower gate narrower so that the separation of the energy sublevels in the y -direction is increased. However, the decrease of the upper gate bias also greatly reduces the Fermi energy. The total effect of decreasing the upper gate bias is the decrease of the oscillation period in the conductance as functions of the lower gate bias. The calculated oscillation period as a function of the lower and upper gate bias explains very well the experimental data.

Monte Carlo study of kink effect in isolated-gate InAs/AlSb high electron mobility transistors

“…In order to carry out the comparison of the measured results ͑extrinsic͒ with those obtained from the simulation ͑intrinsic͒, it is necessary to include, in a postprocessing stage, the parasitic elements that are not considered in the intrinsic MC model. 17 This behavior is the opposite of that found for latticematched InGaAs/InAlAs HEMTs, in which the increase in I D is lower for higher V GS . This occurs because although the electron concentration in the channel is larger when the channel opens, the maximum electron energy is reduced due to the lower gate-to-drain potential.…”

Many-particle Monte Carlo Approach to Electron Transport

“…Dirichlet boundary conditions) and assume ad-hoc modifications of the injection rate to achieve "local" charge neutrality (Bulashenko et al, 1998;Fischetti & Laux, 2001;Gomila et al, 2002;Gonzalez et al, 1997;Gonzalez & Pardo, 1993;Jacoboni & Lugli, 1989;Reklaitis & Reggiani, 1999;Wordelman & Ravaioli, 2000). Some works do also include analytically the series resistances of a large reservoir which can be considered an improvement over the previous boundary conditions (Babiker et al, 1996). Other MC simulators do also consider Neumann boundary conditions (i.e.…”

Monte Carlo Analysis of Impact Ionization in Isolated-Gate InAs/AlSb High Electron Mobility Transistors

“…2b. In order to perform the comparison of the measured results (extrinsic) with those obtained from the simulation (intrinsic), it is necessary to include, in a postprocessing stage, the parasitic elements that are not considered in the intrinsic MC simulation [14]. Thus, drain and source parasitic resistances associated with the contact metallization and part of the ohmic regions not included in the simulation domain have been incorporated into the original MC results, with the best fit being obtained for R S = 0.13 Ω mm and R D = 0.38 Ω mm.…”