title: Understanding Coulomb Scattering Mechanism in Monolayer MoS2Channel in the Presence of h-BN Buffer Layer.
abstract: As the thickness becomes thinner, the importance of Coulomb scattering in two-dimensional layered materials increases because of the close proximity between channel and interfacial layer and the reduced screening effects. The Coulomb scattering in the channel is usually obscured mainly by the Schottky barrier at the contact in the noise measurements. Here, we report low-temperature (T) noise measurements to understand the Coulomb scattering mechanism in the MoS2channel in the presence of h-BN buffer layer on the silicon dioxide (SiO2) insulating layer. One essential measure in the noise analysis is the Coulomb scattering parameter (αSC) which is different for channel materials and electron excess doping concentrations. This was extracted exclusively from a 4-probe method by eliminating the Schottky contact effect. We found that the presence of h-BN on SiO2provides the suppression of αSCtwice, the reduction of interfacial traps density by 100 times, and the lowered Schottky barrier noise by 50 times compared to those on SiO2at T = 25 K. These improvements enable us to successfully identify the main noise source in the channel, which is the trapping-detrapping process at gate dielectrics rather than the charged impurities localized at the channel, as confirmed by fitting the noise features to the carrier number and correlated mobility fluctuation model. Further, the reduction in contact noise at low temperature in our system is attributed to inhomogeneous distributed Schottky barrier height distribution in the metal-MoS2contact region.
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.
authors.forename: Min-Kyu
authors.initials: MK
authors.lastname: Joo
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.
authors.forename: Byoung Hee
authors.initials: BH
authors.lastname: Moon
authors.affiliation: Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Hyunjin
authors.initials: H
authors.lastname: Ji
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.
authors.forename: Gang Hee
authors.initials: GH
authors.lastname: Han
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Gwanmu
authors.initials: G
authors.lastname: Lee
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Seong Chu
authors.identifier: http://orcid.org/0000-0002-0751-1458
authors.initials: SC
authors.lastname: Lim
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Dongseok
authors.initials: D
authors.lastname: Suh
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Young Hee
authors.identifier: http://orcid.org/0000-0001-7403-8157
authors.initials: YH
authors.lastname: Lee
keywords: Coulomb scattering parameter; MoS2; Schottky barrier inhomogeneity; TMD; h-BN; low-frequency noise