High‐Stability Ultrathin Oxide Transistors via Defect Engineering for High‐Performance Capacitorless DRAM

Abstract The rapid development of generative artificial intelligence is driving the growing demand for high‐capacity dynamic random‐access memory (DRAM). Amorphous oxide semiconductor‐based 2T0C DRAM has garnered considerable attention for its potential in overcoming the scaling limitations of conventional 1T1C DRAM. However, inherent stability issues have hindered device performance and practical adoption. In this work, high performance and excellent bias stability in ultrathin indium‐gallium‐oxide (IGO) field‐effect transistors through O ₃ ‐based HfO ₂ passivation is demonstrated. This improvement results from the suppression of shallow‐level defects, deep‐level oxygen vacancies, and hydrogen impurities, leading to a high field‐effect mobility of 35 cm ² V ⁻¹ s ⁻¹ , a positive threshold voltage, and outstanding stability—exhibiting only a +5‐mV threshold voltage shift under −5 MV cm ⁻¹ bias for 1 h. The resulting 2T0C DRAM cell achieves a retention time of over 30 000 s—a 100 × improvement over unpassivated devices—together with a 10 ns write speed, 4‐bit storage capability, and endurance exceeding 10 ¹¹ cycles, representing a viable platform for future high‐density memory applications.