Fig. 1. Fabrication processes and characterization of our vertical self-aligned device.

a–f Schematics of device fabrication process including 6 steps: stacking of MoS₂/BN/graphene heterostructure (a), folding of structure using PDMS tip (b), formation of vdW Fin-heterostructure (c), deposition of the top metal contact (d), peeling off the folded heterostructure (e), transfer of the folded heterostructure to realize self-aligned vertical contact (f). g The perspective view schematic of the device. h Optical image of a typical device. i False-colored TEM image of a representative device, where MoS₂ channel is blue, BN dielectric is green, and graphene is gray. L_ch is the channel length. d is the thickness of the whole folded heterostructure.