A simple and highly reproducible single electron transistor (SET) has been fabricated using gated silicon nanowires. The structure is a metal-oxide-semiconductor field-effect transistor made on silicon-on-insulator thin films. The channel of the transistor is the Coulomb island at low temperature. Two silicon nitride spacers deposited on each side of the gate create a modulation of doping along the nanowire that creates tunnel barriers. Such barriers are fixed and controlled, like in metallic SETs. The period of the Coulomb oscillations is set by the gate capacitance of the transistor and therefore controlled by lithography. The source and drain capacitances have also been characterized. This design could be used to build more complex SET devices.The first and most common Coulomb blockade device is the Single Electron Transistor (SET) made with metallic leads and island, and tunnel oxide barriers 1,2 . It is used as sensitive electrometers 3 or electron pumps allowing to control the transfer of electrons one by one 4,5 . Since then very important efforts have been devoted to fabricate silicon SETs, mostly to integrate SETs together with regular transistors for building logic circuits 6,7 , and more recently for quantum logic experiments with single charge or spin in silicon quantum dots 8,9 . An important challenge is to increase the temperature of operation from the typical sub-kelvin range of original devices up to much higher temperatures. The required size of the island is of the order of the nm, and therefore out of control of current fabrication processes. Researchers took advantage of natural disorder to create such extremely small islands, mostly with constrictions in disordered thin films 10,11,12,13,14 . More recently 15 undulated thin films have been used, as well as pattern-dependent oxidation 16 .We followed another approach based on etched silicon nanowires without constrictions, as pionnered by Tilke et al. 17 and more recently Namatsu et al. 18 , and also Kim et al. 19 and Fujiwara et al. 20 . In the two first cases the formation of a Coulomb island in a nanowire underneath a very large gate was studied. In the two others two gates were defined above a nanowire, each of them acting as a tunable barrier for entering/exiting the single electron box delimited by these gates. Although this scheme allowed logic operations to be performed at 300K 15,16 , it remains a complex architecture since up to 4 gates are needed for proper operation. Our SET is much simpler since it requires a single gate to define the quantum dot, while the barriers are fixed, like in metallic SETs. Periodic Coulomb blockade is observed, with a period solely determined by the surface area of a single gate. It is therefore controlled by lithography, not by disorder. With current state of the art electron beam lithography the limit in operating temperature is of the order of 10 K. The schematics of our device is essentially similar to the original metallic SETs, the tunnel oxide barriers being re-
