Memory state sensing based on cell capacitance

摘要

A memory cell and method for operating a memory cell including a bidirectional access device and memory element electrically coupled in series. The bidirectional access device includes a tunneling capacitance. The memory element programmable to a first and second state by application of a first and second write voltage opposite in polarity to one another. The memory element has a lower capacitance in the first state than the second state. A read unit senses a transient read current due to a voltage drop upon application of a read voltage. Determining if the memory element is the first or second state is based on whether the read current is greater or less than a sense threshold. The sense threshold is based on a capacitance ratio between the first and second state.

主权项

1. A memory cell comprising:
a bidirectional access device including a tunneling capacitance; a memory element electrically coupled in series circuit with the bidirectional access device, the memory element programmable to one of a first state and a second state, the memory element having a first capacitance at the first state and a second capacitance at the second state, the first capacitance being lower than the second capacitance, the memory element programmable to the first state by application of a first write voltage and programmable to the second state by application of a second write voltage in opposite polarity to the first write voltage; and a read unit configured to sense a transient read current due to a voltage drop across the memory element and bidirectional access device upon application of a read voltage.