Ion optics of parallel scan implanter using two octupole deflectors

Ion optics of parallel scan type ion implanter using two geometrically similar octupoles are described. By ion optical analysis taking into account fringing effect of octupoles and checking up with experiment, it has become clear that the dose contour lines are concentric ellipses calculatable from dimensional parameters of the scanner composed of two octupoles. Parallel scan implanters up to 430 kev for 8-inch wafers have been successfully designed and manufactured based on this fact.