A chalcogenide memory cell includes a lower electrode, a chalcogenide
layer, and an upper electrode. The lower electrode includes a tapered
cavity. The chalcogenide layer is formed in the tapered cavity of the
lower electrode. One side of the chalcogenide layer is adjacent to the
lower electrode. The upper electrode is formed in a second cavity formed
by the chalcogenide layer so that the upper electrode substantially fills
the second cavity. The upper electrode is adjacent to the other side of
the chalcogenide layer. Information is stored and retrieved by passing
current between the upper electrode and the lower electrode. The tapered
cavity of the lower electrode is formed through anisotropic etching or
through sidewall-application. Undesired currents are prevented using an
additional dielectric layer or by using an additional conductive layer
that forms a p-n junction with the lower electrode.