| AVS 64th International Symposium & Exhibition | |
| 2D Materials Focus Topic | Wednesday Sessions |
| Session 2D+EM+MN+NS-WeA |
| Session: | 2D Device Physics and Applications |
| Presenter: | Antonio T. Lucero, University of Texas at Dallas |
| Authors: | A.T. Lucero, University of Texas at Dallas J.B. Lee, University of Texas at Dallas L. Cheng, University of Texas at Dallas H.S. Kim, University of Texas at Dallas S.J. Kim, University of Texas at Dallas J. Kim, University of Texas at Dallas |
| Correspondent: | Click to Email |
Two-dimensional transition metal dichalcogenide (TMD) materials are a subject of intense research for use as future, low-power semiconductors. The successful fabrication of TMD based transistors requires a scalable dielectric deposition process. Atomic layer deposition (ALD) is commonly used to grow high-k gate dielectrics, though deposition of thin, pin-hole free dielectrics is challenging due to the chemically inert basal plane of most TMD materials. To overcome this limitation, surface functionalization processes have been developed to improve ALD nucleation.
In order to elucidate the effects of surface functionalization and subsequent ALD on the electrical characteristics of TMD transistors we use an in-situ electrical characterization system to measure the electrical properties of TMD transistors at various steps during the deposition process. MoS2 backgated transistors are loaded into an ultra-high vacuum (UHV) cluster tool where samples can be transferred under UHV conditions between various chambers. The cluster tool is equipped with a thermal ALD chamber, a hollow cathode plasma enhanced ALD chamber, a plasma enhanced chemical vapor deposition chamber, and a UHV electrical probe station. Results for ozone, nitrogen radical, and nitrogen plasma functionalization will be presented. The effect of surface dipoles, precursor adsorption and coverage, and nucleation during the ALD process will be discussed as they relate to the electrical characteristics of the device.
This work was supported by the SWAN Center, a SRC center sponsored by the Nanoelectronics Research Initiative and NIST, and by NRF (No. 2015M3D1A1068061) in Korea. We thank TMEIC for providing the ozone generator and nitrogen radical generator used in this work.