1：Experimental Design and Method Selection:

The study investigates the layered removal of MoS2 using low-power oxygen plasma treatment, followed by water dipping and re-sulfurization. The design includes controlling plasma power and treatment time to fully oxidize the topmost MoS2 layer, leveraging differences in adhesion and solubility for layer detachment.

2：Sample Selection and Data Sources:

MoS2 films are prepared on sapphire substrates via RF sputtering of Mo metal and sulfurization in a furnace. Samples include bi-layer and 4-layer MoS2, with cross-sectional HRTEM, Raman, and PL spectra used for characterization.

3：List of Experimental Equipment and Materials:

RF sputtering system (40 W power, 5×10?3 Torr pressure, Ar gas), hot furnace for sulfurization (800°C, S powder), low-pressure RF oxygen plasma system (20 W power, 0.4 Torr pressure, O2 gas), de-ionized water, HORIBA Jobin Yvon HR800UV Raman spectroscopy system (488 nm laser), FEI Tecnai G2 F20 transmission electron microscopy system (200 kV), BRUKER Dimension ICON AFM system, AFM tip coated with MoS2 for adhesion measurements.

4：4 Torr pressure, O2 gas), de-ionized water, HORIBA Jobin Yvon HR800UV Raman spectroscopy system (488 nm laser), FEI Tecnai G2 F20 transmission electron microscopy system (200 kV), BRUKER Dimension ICON AFM system, AFM tip coated with MoS2 for adhesion measurements. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Mo deposition on sapphire substrates via RF sputtering; sulfurization in furnace with Ar carrier gas and S powder; oxygen plasma treatment (20 W, 10 s) to oxidize topmost MoS2 layer; dipping in de-ionized water (10 s) to detach oxidized layer; re-sulfurization to recover MoS2 film; characterization using Raman, PL, HRTEM, and AFM; adhesion force measurements with MoS2-coated AFM tip on MoOx, MoS2, and sapphire surfaces.

5：Data Analysis Methods:

Raman spectra analysis for peak differences (Δk between E2g1 and A1g peaks) to determine layer numbers; PL spectra analysis for intensity and peak shifts; HRTEM for cross-sectional imaging; AFM force curve measurements for adhesion forces; current-voltage characteristics for electrical analysis of MoS2 devices.