Attoampere Level Leakage Current in Chemical Vapor Deposition-Grown Monolayer MoS₂ Dynamic Random-Access Memory in Trap-Assisted Tunneling Limit.

Abstract

MoS₂, one of the most researched two-dimensional semiconductor materials, has great potential as the channel material in dynamic random-access memory (DRAM) due to the low leakage current inherited from the atomically thin thickness, high band gap, and heavy effective mass. In this work, we fabricate one-transistor-one-capacitor (1T1C) DRAM using chemical vapor deposition (CVD)-grown monolayer (ML) MoS₂ in large area and confirm the ultralow leakage current of approximately 10^-18 A/μm, significantly lower than the previous report (10^-15 A/μm) in two-transistor-zero-capacitor (2T0C) DRAM based on a few-layer MoS₂ flake. Through rigorous analysis of leakage current considering thermionic emission, tunneling at the source/drain, Shockley-Read-Hall recombination, and trap-assisted tunneling (TAT) current, the TAT current is identified as the primary source of leakage current. These findings highlight the potential of CVD-grown ML MoS₂ to extend the retention time in DRAM and provide a deep understanding of the leakage current sources in MoS₂ 1T1C DRAM for further optimization to minimize the leakage current.