Effect of Al2O3 Deposition on Performance of Top-Gated Monolayer MoS2‑Based Field Effect Transistor

• Published in: ACS applied materials & interfaces Vol. 8; no. 41; pp. 28130 - 28135
• Main Authors: Song, Jeong-Gyu, Kim, Seok Jin, Woo, Whang Je, Kim, Youngjun, Oh, Il-Kwon, Ryu, Gyeong Hee, Lee, Zonghoon, Lim, Jun Hyung, Park, Jusang, Kim, Hyungjun
• Format: Journal Article
• Language: English
• Published: American Chemical Society 19-10-2016
• Subjects: molybdenum disulfide; two-dimensional materials; atomic layer deposition; field-effect transistor; transition-metal dichalcogenides
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.6b07271

Deposition of high-k dielectrics on two-dimensional MoS2 is an important process for successful application of the transition-metal dichalcogenides in electronic devices. Here, we show the effect of H2O reactant exposure on monolayer (1L) MoS2 during atomic layer deposition (ALD) of Al2O3. The results showed that the ALD-Al2O3 caused degradation of the performance of 1L MoS2 field effect transistors (FETs) owing to the formation of Mo–O bonding and trapping of H2O molecules at the Al2O3/MoS2 interface. Furthermore, we demonstrated that reduced duration of exposure to H2O reactant and postdeposition annealing were essential to the enhancement of the performance of top-gated 1L MoS2 FETs. The mobility and on/off current ratios were increased by factors of approximately 40 and 103, respectively, with reduced duration of exposure to H2O reactant and with postdeposition annealing.