Vertical Sidewall MoS2 Growth and Transistors

We present novel growth of the two-dimensional (2D) semiconductor MoS 2 directly on oxide/Si sidewalls as deep as $3\ \mu \mathrm{m}$ , demonstrating the first vertical 2D transistors with $I_{\mathrm{o}\mathrm{n}}/I_{\mathrm{off}} > 10^{7}$ and $I_{\mathrm{o}\mathrm{n}}\approx 30\mu \mathrm{A}/\mu \mathrm{m}$ , showing promise for high-density memory selector applications. We also demonstrate direct growth on high-k AbO 3 , an important step towards realizing VLSI-compatible 2D transistors. Our results show that 2D semiconductors can be implemented on non-planar surfaces with amorphous dielectrics for 3D back-end-of-line (BEOL) integration and high-density vertical memory selectors.