Amorphous silicon doped with fluorine for selectors of resistive random access memory cells

Abstract

Provided are resistive switching memory cells having selectors and methods of fabricating such cells. A selector may be disposed between an electrode and resistive switching layer. The selector is configured to undergo an electrical breakdown when a voltage applied to the selector exceeds a selected threshold. The selector is formed from amorphous silicon doped with fluorine. The concentration of fluorine may be between about 0.01% atomic and 3% atomic, such as about 1% atomic. Amorphous silicon has a larger band gap than, for example, crystalline silicon and, therefore, has a lower leakage. Dangling bond and weak bond states appearing in the mid-gap position of amorphous silicon are eliminated by adding fluorine. Fluorine binds to and passivates defects. In some embodiments, a fluorine reservoir is positioned in a low current density region of the memory cell to counter diffusion of fluorine from the selector into other components.