Self Assembled Organic Monolayers such as organosilanes and Inorganic monolayers such as dichalcogenide semiconductor materials attracts wide research interest for potential nanoelectronics applications. We studied the scaling limit of Organic Monolayer such as Trichloro(1H,1H,2H,2H-perfluorooctyl)-silane (FOTS), Hexamethyldisilazane (HMDS) and Inorganic Monolayers such as hexagonal - Boron Nitride (h-BN) and Molybdenum disulfide (MoS2) based MOS devices. We examined the following Organic Monolayer based configurations such as Au/FOTS/p-Si and Au/HMDS/p-Si and the Inorganic based configurations such as Au/MoS2/SiO2/p-Si, Au/h-BN/SiO2/p-Si and compared with Au/SiO2/p-Si MOS configuration by the energy band diagram program and MOSFeT simulation softwares. The calculation of Id-Vg curves and CV characteristics of monolayer FOTS, HMDS, BN and MoS2 FETs are reported. The results of these monolayer FETs show smaller drain induced barrier lowering (DIBL) and reduces threshold voltage than 2nm-thick-dielectric SiO2 FETs at a channel length of 10nm with the same gating.