Time of Flight – Secondary Ion Mass Spectroscopy Profiling of Self-Assembled Monolayer Patterns Based on Vapor Deposition Technique

Abstract

It is crucial to develop novel metrology techniques in a semiconductor fabrication process for characterizing a thin film with a thickness of a few nanometers, as well as the material profile of the film accurately. Uniform trichlorosilane (1H,1H,2H,2H-perfluorodecyltrichlorosilane) derived self-assembled monolayer film patterns were fabricated by several conventional semiconductor fabrication techniques incorporated, including photolithography, vapor deposition, and lift-off technique. The patterned trichlorosilane self-assembled monolayer patterns were thoroughly characterized by Time-of-Flight Secondary Ion Mass Spectrometry, and precise two-dimensional self-assembled monolayer patterns were reconstructed through corresponding ions and ion clusters feature peaks. Additionally, three-dimensional self-assembled monolayer patterns were reconstructed layer by layer through gas cluster ion beam etching and two-dimensional mapping analysis in an alternate way, which verifies that vapor-based trichlorosilane self-assembled monolayer patterns were precisely fabricated and Time-of-Flight Secondary Ion Mass Spectrometry is highly surface-sensitive to obtain accurate information about the self-assembled monolayer pattern in a point-by-point manner. Time-of-Flight Secondary Ion Mass Spectrometry technique could be used as a metrology technique in the semiconductor process with high-quality self-assembled monolayer micro and nanostructures.