Resistance switching memory operation using the bistability in current–voltage characteristics of GaN/AlN resonant tunneling diodes

Abstract

Resistance switching memory operations using the bistability in the current–voltage (I–V) characteristics of GaN/AlN resonant tunneling diodes (RTDs) were investigated to realize an ultrafast nonvolatile memory operating at a picosecond time scale. Resistance switching memory operations based on electron accumulation due to intersubband transitions and electron release due to tunneling current were demonstrated with high reproducibility at room temperature when the leakage of electrons accumulating in the quantum well from the deep level in the AlN barrier was suppressed. A nonvolatile memory for the processor core in a normally off computing system is expected to be realized using the bistability in the I–V characteristics of GaN/AlN RTDs.

Growth and Characterization of GaN/AlN Resonant Tunneling Diodes for High‐Performance Nonvolatile Memory

“…In previous works, we concluded that the leakage of electrons from the quantum well is due to the E DL and E ′ DL , and it depends on the density of dislocations in the quantum well and the fluctuation in the well and barrier widths. [ 15–17 ] Therefore, further improvements of crystal quality of GaN/AlN RTDs are needed to realize a more stable ON/OFF switching. Alternatively, a new quantum structure introducing the AlGaN interlayers, as reported by an all‐optical switch based on intersubband transitions, might be effective in suppressing the leakage of electrons from the quantum well.…”

“…Therefore, we have studied a new nonvolatile memory using the intersubband transitions in GaN/AlN resonant tunneling diodes (RTDs). [ 14–18 ] This new memory, called resonant tunneling random‐access memory (RT‐RAM), has the potential to realize a high‐speed nonvolatile RAM operating at the picosecond time scale and to be used in the high‐speed region in normally off computing systems and the other applications, such as field‐programmable gate array and sensor network systems.…”

“…However, it has been suggested that the instability of nonvolatile memory operations is caused by the small leakage of electrons between quantum well and outsides through the crystal defects in GaN/AlN RTDs. [ 16,17 ]…”

ULTRARAM: Toward the Development of a III–V Semiconductor, Nonvolatile, Random Access Memory

“…The intricate physics of the tunneling mechanism used here and a comparison of ULTRARAM with current and emerging memory technologies are described in detail in our previous work for the interested reader [5]. Additionally, the devices out-perform other resonant-tunneling-based memories in endurance benchmarks with at least a similar logic retention time [7], [8]. Most importantly, the FG design allows for high-density array architectures and the possibility of vastly improved readout (1/0) contrast [5].…”

Stabilization of nonvolatile memory operations using GaN/AlN resonant tunneling diodes by reducing structural inhomogeneity

“…On the basis of the above background, we have studied a new nonvolatile memory based on the intersubband transitions and electron accumulation in GaN=AlN resonant tunneling diodes (RTDs). [11][12][13] This new memory, called resonant tunneling RAM (RT-RAM), has the potential to create a high-speed nonvolatile RAM operating on picosecond time scales, which can be used in the L1 cache memory in normally-off computing systems.…”