A microelectronic device comprises a stack structure, cell pillar structures, an active body structure, digit line structures, and control logic devices. The stack structure comprises vertically neighboring tiers, each of the vertically neighboring tiers comprising a conductive structure and an insulative structure vertically neighboring the conductive structure. The cell pillar structures vertically extend through the stack structure and each comprise a channel material and an outer material stack horizontally interposed between the channel material and the stack structure. The active body structure vertically overlies the stack structure and is in contact with the channel material of the cell pillar structures. The active body structure comprises a metal material having a work function greater than or equal to about 4.7 electronvolts. The digit line structures vertically underlie the stack structure and are coupled to the cell pillar structures. Memory devices, electronic systems, and methods of forming a microelectronic device are also described.

There is provided a diode including an anode electrode provided on a side of a front surface of a semiconductor substrate, an interlayer dielectric film disposed between the semiconductor substrate and the anode electrode, a first anode region of a first conductivity type provided on the front surface of the semiconductor substrate, a second anode region of a second conductivity type, which is different from the first conductivity type, provided on the front surface of the semiconductor substrate, a first contact hole provided in the interlayer dielectric film, causing the anode electrode to be in Schottky contact with the first anode region, and a second contact hole provided in the interlayer dielectric film and different from the first contact hole, causing the anode electrode to be in ohmic contact with the second anode region.