Super-paramagnetic fluctuation of a nanomagnet, when confined by a strong easy-plane anisotropy, can yield GHz speed random signal. A magnetic tunnel junction converts such moment movement into conductance fluctuation, and is useful as an entropy source for modern computing circuits. Here, the authors experimentally explore the base-line behavior of easy-plane magnetic tunnel junctions in the super-paramagnetic limit, using a CMOS back-end integrated fabrication process, and introduce some measurement methodologies to identify factors in device materials and fabrication in need of future optimization.