Magnetic force microscopy measurement of current on integrated circuits

In IC failure analysis current is often used to indicate the presence of a defective device. By imaging the magnetic field produced by current flowing in an IC the defective devices can be located. In this paper we will present experimental results on imaging current carrying lines on integrated circuits using MFM. We have experimentally determined that MFM is capable of measuring out-rents as small as 1muAsimilar to10muA on ICs. We have also carried out simulations comparing MFM imaging with experimental results. Using these simulations we have devised a method to locate accurately the position of the internal current carrying faults from MFM images. This technique has significant potential for IC fault location and other IC failure analysis applications.