Análisis de efectos de carga superficial en nanodispositivos semiconductores modelizados mediante simulaciones Monte Carlo

High-frequency response and thermal effects in GaN diodes and transistors: modeling and experimental characterization

“…In addition, it is a very suitable tool to study physical phenomena related with noise and uctuations. By means of MC technique, it is possible to generate values of a variable following a complicated probability distribution through random numbers distributed between 0 and 1 [53].…”

“…The free-ight time of the particle, the scattering mechanism taking place at the end of the free ight and the state after the scattering event (energy and momentum) are randomly determined (according to the appropriate distribu- for the movement of carriers and for the solution of Poisson's equation [58]. At the end of each time step ∆t, carriers are frozen and the potential to be used in the next time-step is calculated self-consistently with the charge distribution [53]. The scheme of the 2D device simulator is shown in Figure 1.8(b).…”

“…In our simulations, the following scattering mechanisms are considered for both We do not consider optical non-polar scattering, since this mechanism takes place only in L-valleys and it is not signicant in GaN. More details about the scattering mechanisms can be found in previous dissertations by the group [53,55,56,58,64].…”

“…In free surfaces, Neumann BCs are imposed to solve the potential (zero normal derivative) and specular reection is applied to carrier movement. In the case of heterojunctions (present in the devices under analysis), the continuity of the displacement vector is applied, including the term corresponding to surface charges in case these are present (like in the top of the devices or at heterojunctions with piezoelectric charges) [53].…”

“…To model this eect a thermal velocity distribution f th (v) is weighted by the velocity perpendicular to the contact v ⊥ , since an electron with v ⊥ = 0 would never cross the barrier. Thus, as model for the velocity distribution we use [53]…”