A novel antifuse structure with planar-type polysilicon pad is described. The formation of a link between the aluminum electrodes after application of a programming voltage was also investigated. The structure consists of Al/SiO2/poly-Si/SiO2/Al layers. The poly-Si pac! was doped with boron and the thickness of the antifuse dielectric was 9 nm. When a programming voltage is applied, the electrodes are connected by the mass transfer of aluminum through the dielectric and the doped polysilicon pad. The on-state resistance of about 10 Omega, which is the lowest on-state resistance ever reported, is obtained after breakdown with 9.9 V programming voltage. Scanning Anger microscopy analyses show the propagation of a link, as mass transfer of aluminum in the boron doped polysilicon pad. The elliptical link has a maximum diameter of 1.0 mu m in the horizontal direction and a minimum diameter of 320 nm in the vertical direction.