Ferroelectric memory based on molybdenum disulfide and ferroelectric hafnium oxide

Recently, ferroelectric hafnium oxide (HfO$_{\mathrm{2}})$ was discovered as a new type of ferroelectric material with the advantages of high coercive field, excellent scalability (down to 2.5 nm), and good compatibility with CMOS processing. In this work, we demonstrate, for the first time, 2D ferroelectric memories with molybdenum disulfide (MoS$_{\mathrm{2}})$ as the channel material and aluminum doped HfO$_{\mathrm{2}}$ as the ferroelectric gate dielectric. A 16 nm thick layer of HfO$_{\mathrm{2}}$, doped with 5.26{\%} aluminum, was deposited via atomic layer deposition (ALD), then subjected to rapid thermal annealing (RTA) at 1000 \textdegree C, and the polarization-voltage characteristics of the resulting metal-ferroelectric-metal (MFM) capacitors were measured, showing a remnant polarization of \textasciitilde 0.6 $\mu $C/cm$^{\mathrm{2}}$. Ferroelectric memories with embedded ferroelectric hafnium oxide stacks and monolayer MoS$_{\mathrm{2}}$ were fabricated. The transfer characteristics after program and erase pulses revealed a clear ferroelectric memory window. In addition, endurance (up to 10,000 cycles) of the devices were tested and effects associated with ferroelectric materials, such as the wake-up effect and polarization fatigue, were observed. This research can potentially lead to advances of 2D materials in low-power logic and memory applications.