Monte Carlo Investigation of Hot Carriers Generated by Subpicosecond Laser Pulses in Schottky Barrier Diodes
The self-consistent Ensemble Monte Carlo (E.M.C.) method is used to study the dynamics of carriers generated by subpicosecond laser pulses in a Silicon n+/n/metal submicron Schottky diode. The E.M.C. model for the Schottky diode is the same presented in , with the inclusion of hole dynamics. In this model the Poisson’s equation is solved using an accurate collocation method , which gives a very precise solution for the electric field E(0) on the ohmic contact boundary. This allows us to determine the current injected through the ohmic contact using the relation J=n+μ o E(0), where μo is the low field mobility in an n+ contact region. This is justified if the width of the region is at least a few Debye lengths, so that we consider the carriers at the ohmic contact boundary to be in equilibrium with the lattice. In this way we can model the depletion of carriers and fully account for the non-charge-neutral behavior of the Schottky barrier diode, keeping track of the carriers exiting the device and allocating on the metal side the ones which are not reinjected. Tunnelling current from the semiconductor to the metal is included by a WKB approach as in , with an improved formulation of the tunnelling probability, which takes into account nonparabolicity and the effect of finite bandgap .
KeywordsOhmic Contact Collocation Method Schottky Diode Schottky Barrier Diode Photoexcited Electron
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- 1.P. Lugli, U. Ravaioli and D. K. Ferry: “Monte Carlo simulation of contacts in submicron devices”, AIP Conference Procedings n. 122, The Physics of VLSI, p. 162, Palo Alto (1984).Google Scholar
- 2.U. Ravaioli, P. Lugli, M. A. Osman and D. K. Ferry: “Advantages of collocation methods over finite differences in one-dimensional simulation of submicron devices”, II Conference on Numerical Simulation of VLSI Devices, Boston (1984), to be published.Google Scholar
- 4.R. J. Phelan, D. R. Larson, N. V. Frederick and D. L. Franzen: Proceedings of SPIE, Picosecond Optoelectronics, 439, 207 (1983).Google Scholar