Abstract:
In this work, we report atomic-layer-deposited (ALD) based all-oxide transistors toward vertically stacked high-density logic and memory for 3-D integration. This structu...Show MoreMetadata
Abstract:
In this work, we report atomic-layer-deposited (ALD) based all-oxide transistors toward vertically stacked high-density logic and memory for 3-D integration. This structure utilizes thick degenerated ALD In2O3 as the conducting gate, and ALD In2O3 thin film itself serves as source/drain contacts to the ALD In2O3 channel without metal contacts and gate formation. The all-oxide field-effect transistors (AOFETs) not only survived under high-temperature annealing over 400~^{\circ } C but also gained a boosted on-/off-ratio over 10^{{7}} with subthreshold swing (SS) close to 60 mV/dec at room temperature. AOFETs present high uniformity and very robust reliability with a threshold voltage instability ( \boldsymbol {\Delta } {V}_{\text {TH}}\text {)} of −5 and −50 mV under positive bias stress (PBS) and negative bias stress (NBS) tests for 10^{{4}} s. The vertical AOFETs (V-AOFETs) demonstrate good gate modulation from sidewall In2O3 with thickness as well as gate length ( {T}_{\text {IO,{g}}}\text {)} of 10 nm, achieving on-/off-ratio over 10^{{5}} and maximum current ( {I}_{\max }\text {)} over 160~\boldsymbol {\mu } A/ \boldsymbol {\mu } m. Vertical all-oxide ferroelectric FETs (V-AO-FeFETs) show a memory window (MW) of 1.85 V, with endurance and retention extended to 10^{{12}} cycles and ten years at room temperature, respectively. These findings illustrate that the vertical-channel all-oxide devices based on ALD oxide semiconductors (OS) are promising candidates for future high-density logic and memory applications in 3-D integration.
Published in: IEEE Transactions on Electron Devices ( Volume: 71, Issue: 12, December 2024)