Park, Euyjin Kim, Seung-Hwan Min, Seong-Ji Han, Kyu-Hyun Kim, Jong-Hyun Kim, Seung-Geun Ahn, Tae-Hang Yu, Hyun-Yong 2024-10-26T15:30:34Z 2024-10-26T15:30:34Z 2024-10-25 2024-10 1936-0851 https://pubs.kist.re.kr/handle/201004/150889 Two-dimensional (2D) transition metal dichalcogenides (TMDCs) known for their exceptional electrical and optical properties have emerged as promising channel materials for next-generation electronics. However, as strong Fermi-level pinning (FLP) between the metal and the 2D TMDC material at the source/drain (S/D) contact decides the Schottky barrier height (SBH), the transistor polarity is fixed to a certain type, which remains a challenge for the 2D TMDC field-effect transistors (FETs). Here, a S/D contact structure with a quasi-zero-dimensional (quasi-0D) contact interface, in which the dimensionality reduction effect alleviates FLP, was developed to gain controllability over the polarity of the 2D TMDC FET. As a result, conventional metal contacts on the WSe2 FET showed n-type characteristics due to strong FLP (pinning factor of 0.06) near the conduction band, and the proposed quasi-0D contact enabled by the Ag conductive filament on the WSe2 FET exhibited p-type characteristics with a SBH very close to the Schottky-Mott rule (pinning factor of 0.95). Furthermore, modeling of Schottky barriers of conventional contacts, one-dimensional (1D) contacts, and quasi-0D contacts revealed that the SBH of the quasi-0D contact is relatively less subject to interface dipoles that induce FLP, owing to more rapid decaying of dipole energy. The proposed contact in this study provided a method that progressed beyond the alleviation of FLP to achieve controllable polarity. Moreover, reducing the contact dimensionality to quasi-0D will enable high compatibility with the further scaled-down nanoscale device contact structure. English American Chemical Society Quasi-Zero-Dimensional Source/Drain Contact for Fermi-Level Unpinning in a Tungsten Diselenide (WSe2) Transistor: Approaching Schottky-Mott Limit Article 10.1021/acsnano.4c09384 1 ACS Nano, v.18, no.43, pp.29771 - 29778 ACS Nano 18 43 29771 29778 N scie scopus 001333461600001 2-s2.0-85206621720 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Chemistry Science & Technology - Other Topics Materials Science Article Fermi-level pinning Schottky barrier height modulation two-dimensional transition metal dichalcogenides conductivefilament quasi-zero-dimensional