Ultra-thin MoO3 film goes wafer-scaled nano-architectonics by atomic layer deposition

From the technical and design points of view, it is quite difficult to maintain the integrity of nano-films during the deposition process to fabricate practical devices based on ultra-thin semiconductor films. Thus, defect-free wafer-scaled development of ultra-thin quasi two-dimensional (2D) oxide semiconductor films represents serious challenges. Plasma-enhanced atomic layer deposition (PE-ALD) made it possible to fabricate ultra-thin MoO3 nanofilms (4.6 nm) over the wafer-scaled granular Au electrode. The detailed ALD recipe for ultra-thin MoO3 film was established and verified. The C12H30N4Mo and O-2 plasma were used as Mo precursor and oxygen source, respectively. The growth of crystalline phases was observed when the ALD temperature of 250 degrees C was employed. Higher ALD temperature resulted in an increase of growth rate over Au substrate (1.21 angstrom/cycle). The precise recipe design enabled the scalable fabrication of environmental sensors based on ultra-thin MoO3 films with precise thickness controllability. Electrochemical sensors based on the fabricated MoO3 nanostructures demonstrated reliable performance to hydrazine (N2H4) detection. (c) 2018 Elsevier Ltd. All rights reserved.