Switching characteristics of nonvolatile memory using GaN/AlN resonant tunneling diodes

The nonvolatile memory operations using GaN/AlN resonant tunneling diodes (RTDs) were investigated to make clear their operation mechanism and operation speed. The ON-OFF switching characteristics were investigated by inputting pulse voltage sequences with pulse widths from millisecond to nanosecond order. The ON/OFF current ratio of about 30 was almost independent of the pulse width. The switching time from the ON state to OFF state was estimated to be approximately 10 ns by fitting a large reduction in current due to resistivity change with an exponential curve. These results support that the nonvolatile memory operations using GaN/AlN RTDs were caused by intersubband transitions and electron accumulation in the quantum well. Also, it was suggested that a high-speed nonvolatile memory operating at picosecond time scales can be realized by reduction in the contact resistance and capacitance of GaN/AlN RTDs. (C) 2019 The Japan Society of Applied Physics