Fig. 2: Dielectric properties of quasi-vdW layered Sm2O2SO4 single crystal.
From: High-κ samarium oxysulfate dielectric for two-dimensional electronics with enhanced gate coupling
a Schematic (top) and OM image (left bottom) and Raman spectroscopy (right bottom) of the double-gate graphene (Gr) field-effect transistor (FET) with the Sm2O2SO4 top-gate dielectric on SiO2/Si substrate (here Vtg, Vbg and Vds represent the top-gate voltage, back-gate voltage, and drain-to-source voltage, respectively). Scale bars: 5 µm. b Total resistance of a typical dual-gate graphene FET as the function of Vtg at different Vbg. c Vbg-dependent top-gate Dirac point voltages of the dual-gate graphene FET. d Thickness-dependent capacitance–voltage (C-V) measurements of Sm2O2SO4 nanoplates at measurement frequency of 100 kHz. e Thickness-dependent dielectric constant of Sm2O2SO4 measured by the C-V method. Inset: thickness dependent equivalent oxide thickness (EOT) of Sm2O2SO4. f Current leakage and breakdown characteristics of Sm2O2SO4 nanoplates measured by metal-insulator-metal (MIM) devices with thicknesses ranging from 6.5 to 22.3 nm. The dashed lines mark the limits for various electronic applications. DRAM, dynamic random access memory. g The breakdown field of Sm2O2SO4 at different temperatures. Inset: OM image of the MIM device. Scale bars: 5 µm. h Breakdown field versus effective dielectric constant of ultrathin Sm2O2SO4, compared with various dielectric materials18,20,26,27,32,33,34,35,41,42,43,53,54,55.
