End-Bonded Metal Contacts on WSe2 Field-Effect Transistors
| Autor: | Zheng-Yong Liang, Po-Wen Chiu, Mei-Yin Chou, Chun-Hao Chu, Ho-Chun Lin, Chao-Hui Yeh |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Electron mobility
Materials science business.industry Schottky barrier Transistor General Engineering General Physics and Astronomy Context (language use) 02 engineering and technology Chemical vapor deposition 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention law Logic gate Monolayer Optoelectronics General Materials Science Field-effect transistor 0210 nano-technology business |
| Zdroj: | ACS Nano. 13:8146-8154 |
| ISSN: | 1936-086X 1936-0851 |
| Popis: | Contact engineering has been the central issue in the context of high-performance field-effect transistors (FETs) made of atomic thin transition metal dichalcogenides (TMDs). Conventional metal contacts on TMDs have been made on top via a lithography process, forming a top-bonded contact scheme with an appreciable contact barrier. To provide a more efficient pathway for charge injection, an end-bonded contact scheme has been proposed, in which covalent bonds are formed between the contact metal and channel edges. Yet, little efforts have been made to realize this contact configuration. Here, we bridge this gap and demonstrate seeded growth of end-bonded contact with different TMDs by means of chemical vapor deposition (CVD). Monolayer WSe2 FETs with a CVD-grown channel and end contacts exhibit improved performance metrics, including an on-current density of 30 μA/μm, a hole mobility of 90 cm2/V·s, and a subthreshold swing of 94 mV/dec, an order of magnitude superior than those of top-contact FET counterparts that share the same channel material. A fundamental NOT logic gate constructed using top-gated and end-bonded WSe2 and MoS2 FETs is also demonstrated. Calculations using density functional theory indicate that the superior device performance stems mainly from the stronger metal-TMD hybridization and substantial gap states in the end-contact configuration. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|