MONTE-CARLO SIMULATION OF THE GROWTH OF METALLIC QUANTUM DOTS

The phenomenon of Coulomb Blockade allows to control the flow of indiv idual electrons and has raised hopes of building electronics devices b ased on such phenomenon. In order to observe Coulomb Blockade, islands , or dots, on the nanometre scale must be fabricated in order to obtai n a small enough capacitance for the electrostatic energy associated w ith adding a single electron to the island to exceed thermal fluctuati ons. Coulomb Blockade has been observed both in semiconductor and in m etallic structures. In particular irregular 2D arrays of metallic dots of typical size less than 10nm have been fabricated by means of Elect ron Beam Lithography combined with granular film deposition. In this p aper we present a theoretical study of the grain deposition and subseq uent island formation based on a Monte Carlo technique. The model allo ws to account for a variety of important parameters such as temperatur e, diffusion vs, deposition rate, and in particular the effect of cont acts. Optimum parameters to obtain reproducible Coulomb Blockade devic es are suggested.