| AVS 62nd International Symposium & Exhibition | |
| 2D Materials Focus Topic | Monday Sessions |
| Session 2D+EM+NS+PS+SP+SS+TF-MoM |
| Session: | 2D Materials: Growth and Fabrication |
| Presenter: | Berc Kalanyan, National Institute of Standards and Technology (NIST) |
| Authors: | B. Kalanyan, National Institute of Standards and Technology (NIST) J.E. Maslar, National Institute of Standards and Technology (NIST) W.A. Kimes, National Institute of Standards and Technology (NIST) B.A. Sperling, National Institute of Standards and Technology (NIST) R. Tieckelmann, SEMATECH T. Orzali, SEMATECH R. Beams, National Institute of Standards and Technology (NIST) S.J. Stranick, National Institute of Standards and Technology (NIST) A.V. Davydov, National Institute of Standards and Technology (NIST) |
| Correspondent: | Click to Email |
Two dimensional (2D), layered transition-metal dichalcogenides (TMDs), e.g., MoS2, are of increasing interest for next-generation nanoelectronic and optoelectronic devices. These materials have thickness dependent optical and electrical properties that make them suitable for a variety of applications including integrated circuits. For many applications, high volume manufacturing (HVM) of devices based on TMDs will require deposition techniques that are capable of reproducibly growing wafer-scale, 2D TMD films with monolayer control. To date, such a capability has not been widely demonstrated with typical TMD deposition processes.
This work aims to identify promising chemistries for HVM TMD chemical vapor deposition (CVD) processes. We focus on MoS2 CVD using a variety of precursors (including organometallics, elemental sulfur, and organosulfur compounds) in a research grade single-wafer deposition system equipped with in situ optical diagnostics. The precursor flux is measured using optical mass flow meters installed on the delivery lines while deposition chemistry is characterized in the reactor volume above the deposition surface using in situ Fourier transform infrared (FR-IR) spectroscopy. As-deposited and annealed films are characterized with ex situ techniques, including Raman and photoluminescence spectroscopy, scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy.
Stoichiometric MoS2 films have been prepared from (η5-ethylcyclopentadienyl)-dicarbonylnitrosyl molybdenum and elemental sulfur. As-grown films are smooth and continuous with major MoS2 Raman modes present. Film thickness scales approximately with Mo precursor exposure time and few-layer films can be produced using pulsed injection mode. Furthermore, optical in situ diagnostics allow us to relate metal precursor flux to film crystallinity and facilitate the study of precursor decomposition in the thermal boundary layer.