Transistors have been significantly downsized over the past decades, reaching channel dimensions of around 100 nm. In nanoscale, quantum effects start to play a key role in device operation, allowing the development of applications based on new physics. In silicon nanodevices, for instance, the device downsizing is associated with a reduction of the number of impurities (dopants) incorporated in the channel. Dopants can play an active role in device operation, mediating the electron transport between source and drain. Here, we present a new device concept of a memory based on the interaction between dopants in nanoscale field-effect transistors. As a basis for memory operation, we show experimental results of single-electron charging in individual dopants monitored by a single-electron current flowing through a dopant array.