Growth of organic thin films on Si (100) surfaces: 2-Methyl-4-Nitroaniline (MNA)

We have grown the organic, 2-methyl-4-nitroaniline (MNA), thin films by the ultrahigh vacuum (UHV) process of organic molecular beam deposition (OMBD) and studied the structural and optical properties of the films using atomic force microscopy (AFM), spectroscopic ellipsometry (SE), and angle-resolved X-ray photoelectron spectroscopy (ARXPS) at room temperature. Accurate refractive indices, and , were measured in the spectra range of 1.5-4.5 eV by using a parametric semiconductor model that took the surface roughness effect into account. Non-contact AFM has been used to study the surface diffusion model from its topographic images. Three-dimensional (3D) islands were created on the 2D layer of MNA, which was observed on the reconstructed surface with (100) Si substrate. Islands between 60-80 Å in diameter and 1.5-3 Å in height were distributed randomly on the surface. The chemical properties of the organic thin films on Si substrate were studied by ARXPS with a nonmonochromated Mg Ka X-ray source (1256.6 eV). The new graphical modeling was used to characterize the organic layered structures that can estimate the thickness, concentration, and depth of the deposited layer.