Single ion implantation of Ge donor impurity in silicon transistors

Ge impurities in silicon generate deep donor states in the silicon bandgap. We demonstrate the single ion implantation of Ge ions in the channel of silicon transistors and their electrical activation. Because of the deep donor ground state of Ge, we realize room temperature impurity bands. Our method enables us to create atomic scale conductive paths in silicon with no need of external gate voltages.