Phase transformation of programmed NiSi electrical fuse: Diffusion, agglomeration and thermal stability

Abstract

An advanced CMOS technology process reliability qualification especially for the NiSi poly gated electrical fuse (eFuse) consists of electrical characterization, physical analyses and reliability evaluations. In this paper, insights are given on microstructural behaviors of the programmed NiSi poly gated eFuse induced by the high temperature storage (HTS) test. Both ex- and in-situ transmission electron microscopy (TEM) reveal that the improved post-resistance of the programmed eFuse is attributed to the low temperature growth of Ni3Si2 during HTS test at 250°C. In addition, the Ni agglomeration, the propensity of Ni3Si2 formation on the programmed eFuse with and without void appearance on the fuse link, is comprehensively investigated in conjunction with the eFuse reliability.