Advantages of ion implantation in fabricating hyperabrupt diodes

Hyperabrupt diodes are characterized by a rapid change in capacitance with reverse voltage, due to the widening of the depletion layer through a region of decreasing doping density. When specific requirements are placed on the C-V relationship, one finds it necessary to apply rigorous control in forming the impurity profile. This paper describes the fabrication of such a device by two techniques, diffusion and ion implantation, and shows the striking advantage of ion implantation in fabricating devices with reproducible C-V characteristics at a high yield.