Fig. 1. (Color online) Characterization of a CVD-grown monolayer MoS₂ film. (a) Schematic presentation of the seeding-promoted CVD with a customized inner reactor for the synthesis of monolayer MoS₂. (b) and (c) Line scan of Raman spectra and PL spectra of the monolayer MoS₂ film, performed in this study with a 488 nm laser. (d) A schematic diagram and process flow detailing the device structure are provided. A 285 nm SiO₂ layer serves as the gate dielectric in this design. (e) Transfer characteristics of 20 MoS₂ FETs with L = 3 μm and W = 4 μm, under V_ds = 3 V. (f) Corresponding output characteristics of the MoS₂ FET. V_gs is stepped up from −12 to 30 V by increments of 3 V.

Fig. 2. (Color online) Raman analysis of the MoS₂ FETs before and after 30 keV proton irradiation. (a) Raman spectra of monolayer MoS₂ analysis under different proton fluence. (b) Position of ${\text{E}}_{\text{2g}}^{\text{1}}$ and ${\text{A}}_{\text{1g}}$ in correlation with the proton fluence. The peak position's error bars represent the largest uncertainty present. (c) The peak-to-peak distance and (d) peak intensity ratio for the Raman spectra were measured at 30 different locations within a 5 μm by 6 μm area before irradiation. Insets in the upper right corner of the color maps show the mean (μ) and standard deviation (σ) for each parameter. (e) The peak-to-peak distance and (f) peak intensity ratio for the Raman spectra at the same points after irradiation with a fluence of 10¹⁴ p/cm².

Fig. 3. (Color online) Electrical performance of the MoS₂ FETs before and after 30 keV proton irradiation. (a) A diagrammatic representation of the DD effect in the MoS₂ FET caused by proton irradiation. Representative transfer characteristics obtained from 20 monolayer MoS₂ FETs after proton irradiation with a total fluence of (b) 10¹² p/cm², (c) 10¹³ p/cm², and (d) 10¹⁴ p/cm². Statistical measurements of (e) SS, (f) I_on/I_off, and (g) V_th change, with three different proton irradiation fluences of 10¹², 10¹³, and 10¹⁴ p/cm².

Fig. 4. (Color online) The relationship between radiation absorption cross-section and radiation tolerance. (a) Simulation results of the vacancy number in the source/drain region (Sb/Au/MoS₂/SiO₂/Si) by SRIM. Inset illustrates the simulation domain, encompassing the source/drain contact region. (b) Simulation results of vacancies number in the monolayer, bilayer and trilayer by SRIM. Transfer characteristics of (c) bilayer and (d) trilayer MoS₂ FETs after 10¹⁴ p/cm² proton irradiation measured at different V_ds. Benchmark of the change of (e) ΔSS and (f) ΔV_th caused by DD in other radiation-hard FETs^{[11, 20, 21, 35−39]}.