Large-scale charge storage by scanning capacitance microscopy

Abstract Charge trapping in the silicon nitride-silicon dioxide-silicon (NOS) system has been used for data storage in non-volatile semiconductor memories for many years. Recently, a scanning capacitance microscope has been used to store information densely by locally trapping and de-trapping charge in the NOS system. In this paper we expand on our previous work by demonstrating the storage of 256 kilobits of information over a (120 μm) 2 area. An error rate of less than 0.03% is observed. Track structures have also been etched into some NOS samples in order to aid the location of data which has been stored. The topography and capacitance measurement abilities of our microscope allow the simultaneous acquisition of position information and stored data. These tracks also contribute to confining the trapped charge to a small region.