A capacitance sensor for on-line monitoring of ultrathin polymeric film growth

• Published in: IEEE transactions on components, hybrids, and manufacturing technology Vol. 11; no. 2; pp. 184 - 190
• Main Authors: Zhou, G.-G., Kowel, S.T., Srinivasan, M.P.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-06-1988; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Bridge circuits; Capacitance measurement; Capacitive sensors; Dielectric substrates; Electrodes; Electronics; Exact sciences and technology; Glass; Microelectronic fabrication (materials and surfaces technology); Monitoring; Optical films; Polymer films; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sensor arrays; Monolayer; Soaking; Polymer; Electrical insulation; Real time; Thin film; Processing control; Electrodes; Thickness; Capacitive method; Microelectronic fabrication; Quality control; Langmuir Blodgett layer; Interdigital configuration; Deposition; Organic compounds
• ISSN: 0148-6411; 1558-3082
• DOI: 10.1109/33.2985

An interdigitated metallic electrode array fabricated using standard photolithography and wet-etching techniques, is applied as a capacitance sensor. A theoretical model is developed which predicts a sensitivity of approximately 2 fF/monomolecular layer, well within the detection capability of modern digital bridges. Experimental data from Langmuir/Blodgett depositions of organic and polymeric films accurately confirm the theoretical predictions. The sensors have also provided the first real-time measurements of water exclusion from such films.< >