Absorption of Urea Into Zeolite Layer Integrated With Microelectronic Circuits

A simple and efficient technique allows the direct application of a mixture of zeolite 3A and castor oil onto surfaces, at low temperatures. This same technique can also be used to fabricate iono-electronic devices on silicon wafers for biomedical purposes. In this paper, we investigate the use of a mixture of zeolite together with different vegetable oils aimed at obtaining thinner, more uniform, repeatable layers at even lower temperatures, which are capable of entrapping biological substances, specifically urea molecules. By choosing the proper mixture, the curing temperature can be optimized to make the process compatible with integrated circuit technology. A cold O2 -plasma treatment was used during experimentation to activate the zeolite thin layer on silicon, by removing the residual organic species. The absorption of urea molecules and its interaction with the zeolite framework was investigated through Fourier transform infrared spectroscopy.