MASKLESS FABRICATION OF CONTACT VIAS BY FOCUSED MEV HEAVY-ION BEAM

A focused MeV nickel ion beam was used for making contact vias in a mu ltilayer structure through a passivation layer. The structures had two aluminum layers isolated by a Si3N4 insulating layer. The distributio n of implanted nickel ions was controlled by changing the implantation energy. After the implantation, current-voltage characteristics betwe en the two aluminum layers were measured by a two-point probe method. When the distribution of nickel was adjusted at the Si3N4 insulating l ayer, electrical conduction was observed at the nickel fluence of 1 x 10(17)-2 x 10(18) ions/cm2, and it was found that the conductivity was increased and the breakdown voltage was decreased as the fluence of n ickel ions increased.