Methods of making memory devices with programmable impedance elements and vertically formed access devices

Abstract

A method can include forming a plurality of access transistors, including forming second semiconductor regions over an integrated circuit substrate that are doped to a second conductivity type, the second semiconductor regions being over and in contact with first semiconductor regions doped to a first conductivity type, and forming third semiconductor regions doped to the first conductivity type in contact with the second semiconductor regions; forming a plurality of conductive structures, over and in contact with the third semiconductor regions; and forming programmable impedance memory cells over and in contact with the conductive structures.

Dependencies are inferred from the claim text.