Sb<sub>2</sub>Te<sub>3</sub>/MoS<sub>2</sub> Van der Waals Junctions with High Thermal Stability and Low Contact Resistance
Wen-Hsin Chang, Shogo Hatayama, Yuta Saito, Naoya Okada, Takahiko Endo, Yasumitsu Miyata, Toshifumi Irisawa
Abstract
Abstract Two‐dimensional transition metal dichalcogenides (TMDCs) demonstrate great potential in nanoelectronics devices owing to their high carrier mobility in the atomically thin channel regime. However, high contact resistance between source/drain electrodes and TMDC channels hinders the TMDCs applications in the very‐large‐scale integration (VLSI) field. Here, this work reports atomically aligned van der Waals (vdW) junction fabrications through thermal‐induced crystallization of layered Sb 2 Te 3 electrodes on monolayer MoS 2 using VLSI‐compatible physical vapor deposition and annealing processes. Due to Fermi‐level unpinning with a small band offset between Sb 2 Te 3 and MoS 2 and small density of state of Sb 2 Te 3 , better device performance is demonstrated on MoS 2 MOSFETs with Sb 2 Te 3 /W contact than that of Sb/W contact. Moreover, the ideal vdW junctions are found to demonstrate extreme high‐thermal robustness. No intermixing at the Sb 2 Te 3 /MoS 2 interface or crystallinity degradation of Sb 2 Te 3 is observed after 450 °C annealing, leading to higher thermal stability than its Sb counterpart. Sb 2 Te 3 is a promising candidate as an n‐type contact material for TMDC‐based devices such as MoS 2 , MoSe 2 , and WS 2 in future VLSI electronics and various other applications.