Patent ID: 8895945

Claim:
A dose-measurement device for ion implantation, the device comprising a module (CUR) for estimating implantation current, a secondary electron detector (DSE), and a control circuit (CC) for estimating the ion current by taking the difference between said implantation current and the current from said secondary electron detector, the device being characterized in that said high-energy secondary electron detector comprises a collector (COL, P) supporting exactly three mutually insulated electrodes: a first repulsion electrode (G 1 , A 1 , T 1 ) for repelling charges of a predetermined sign that are to be repelled, said electrode being provided with at least one orifice for passing electrons; a second repulsion electrode (G 2 , A 2 , T 2 ) for repelling charges of the opposite sign that are to be repelled, said electrode also being provided with at least one orifice for passing electrons; and a selection electrode (G 3 , A 3 , T 3 ), this electrode also being provided with at least one orifice for passing electrons.