A MULTIPLE-STATE MEMORY CELL BASED ON THE RESONANT TUNNELING DIODE

The device consists primarily of several molecular-beam-epitaxy (MBE-) grown GaAs/(AlGa)As resonant tunneling diodes connected in parallel. This device exhibits multiple peaks in the I-V characteristic. When a load resistor is connected, the circuit can be operated in a multiple stable mode. With this concept, implementation of three-state and four-state memory cells are made. In the three-state case the operating points at voltages V//0 equals 0. 27 V, V//1 equals 0. 42 V, and V//2 equals 0. 53 V represent the logic levels 0, 1, and 2. Similarly for the four-state memory cell the logic levels voltages are V//0 equals 0. 35 V, V//1 equals 0. 42 V, V//2 equals 0. 54 V, and V//3 equals 0. 59 V. A suggestion of an integrated device structure using this concept is also presented.