High-Speed Formation of Organic Thin Films Using Molecular Layer Deposition with Precise Thickness Control

Abstract

Organic thin films were fabricated by a new growth technique that can control thickness with nanometer level. This method is based on molecular layer deposition of self-assembled monolayers (SAMs) in gas phase. In the MLD method, the high-quality organic multi-layers quickly were able to form under vacuum. The 7-octenyltrichlorosilane as the SAMs precursor was formed by molecular layer deposition at 473K under vacuum. The C=C terminal groups of the SAMs were activated by using O3 treatment in gas phase. It was found that the C=C terminal groups of the SAMs were converted to hydrophilic groups (e.g., OH, aldehydes, carboxylic acid) during the O3 treatment. The TiO2 thin layers for strong interaction between the SAMs molecules were deposited by atomic layer deposition from titanium isopropoxide and water at 473K. These results demonstrated that the organic multi-layers can be formed by repeated SAMs deposition under vacuum. The thin films have been investigated by using x-ray photoelectron spectroscopy, contact angle analysis, transmission electron microscopy, and digital multi-meter.