[TuP3E] E. Physics, spintronics, and novel device concepts

[TuP3E-03] Design and Characterization of GaN/AlN Resonant Tunneling Diodes with AlGaN Interlayers for Nonvolatile Memory Applications

〇Masanori Nagase¹, Tokio Takahashi¹, Mitsuaki Shimizu¹ (1. AIST (Japan))

We studied a nonvolatile memory that uses intersubband transitions and quantum-well electron accumulation in GaN/AlN resonant tunneling diodes (RTDs). This memory has potential use in nonvolatile SRAM, which can be employed for low-level caches in computers and field-programmable gate array (FPGA) cells. However, electron leakage through the deep levels in AlN barriers of GaN/AlN RTDs can degrade the nonvolatile memory characteristics. In this study, the GaN/AlN RTD with an Al_0.6Ga_0.4N interlayer between the GaN spacer and AlN barrier layers on the emitter side was fabricated using the MOVPE technique, obtaining a high ON/OFF ratio of ≈ 10⁴, which was 10 to 100 times higher than those of GaN/AlN RTDs without an Al_0.6Ga_0.4N interlayer. The write and erase voltages (V_write and V_erase) were stabilized. Experimental V_write and V_erase were explained by a theoretical analysis that considers the spontaneous and piezoelectric polarizations in nitride materials. The results indicate that this memory can be further improved by designing the quantum well structure for use in applications such as nonvolatile FPGAs.