Unlocking the performance limits of 2T0C DRAM with Ω-shaped-gated single-crystal In ₂ O ₃ FETs

This study demonstrates high performance Ω-shaped-gated single-crystal In 2 O 3 field-effect transistors (Ω-SC In 2 O 3 FETs), which push the performance boundaries of oxide-based electronics. To showcase these capabilities in a demanding application, a capacitorless two-transistor (2T0C) dynamic random-access memory (DRAM) cell is fabricated based on Ω-SC In 2 O 3 FETs. Specifically, a high average field-effect mobility of 321.7 cm 2 /V·s with an on-off ratio above 10 9 and a steep subthreshold swing (SS) of 64.6 mV/dec are obtained for Ω-SC In 2 O 3 FETs due to the single-crystal In 2 O 3 channel as well as effectively enhanced electrostatic control of the Ω-shaped gate structure. The robust gate bias temperature stress stabilities, including positive and negative bias-temperature stresses, are achieved with a threshold voltage ( V TH ) shift value of −121 and 41 mV for 10 4 s, respectively, which is attributed to low defect density. Moreover, the high-performance capacitorless 2T0C DRAM cell based on Ω-SC In 2 O 3 FETs is constructed, which presents long data retention of 10 5 s, ultrafast access speed of 5 ns, endurance of 10 12 cycles, and storage of 3 bits.