Select device for cross point memory structures
The present disclosure provides a memory cell that includes a resistive memory element disposed between a first conductor and a second conductor, the first conductor and the second conductor configured to activate the resistive memory element. The memory cell also includes a backward diode disposed in series with the memory element between the memory element and either the first conductor or the second conductor.
1. A memory cell, comprising:
a resistive memory element disposed between a first conductor and a second conductor, the first conductor and the second conductor configured to activate the resistive memory element; and
a backward diode disposed in series with the memory element between the memory element and either the first conductor or the second conductor, wherein the backward diode has a threshold voltage that is less than a write voltage of the resistive memory element, but is greater than half a write voltage of the resistive memory element.
2. The memory cell of claim 1 , wherein the resistive memory element comprises at least one of a memristor, a Phase Change Material resistor, a conductive bridge resistor, and a transition metal oxide based resistor.
3. The memory cell of claim 1 , wherein the resistive memory element is configured to be read by applying a voltage across the first conductor and the second conductor that reverse biases the backward diode and is less than a threshold voltage of the backward diode.
4. The memory cell of claim 1 , wherein the resistive memory element is configured to be written by applying a voltage across the first conductor and the second conductor that is greater than a threshold voltage of the backward diode.
5. The memory cell of claim 1 , wherein the backward diode comprises amorphous silicon, microcrystalline silicon, or a combination thereof.
6. A method of forming a memory cell, comprising:
disposing a resistive memory element between two electrodes;
disposing a backward diode in series with the resistive memory element between two electrodes, wherein the backward diode is configured to exhibit a threshold voltage less than a magnitude of a write voltage and greater than approximately one half of the magnitude of the write voltage.
7. The method of claim 6 , wherein disposing the resistive memory element comprises forming a memristor.
8. The method of claim 6 , wherein disposing the backward diode comprises forming a backward diode comprising amorphous silicon, microcrystalline silicon, or a combination thereof, over the resistive memory element.