On the Atomic Layer Deposition of Tantalum Oxide for Field Effect Sensors

Tantalum oxide is a promising material used in electronics, in particular for the production of field effect biosensors. Such biosensors have high sensitivity to changes in surface potential and chemical resistance in aqueous solutions. In addition, highly sensitive pH sensors can be created on the basis of tantalum oxide. We study the process of obtaining a tantalum oxide film by thermal atomic layer deposition using water and a PDMAT precursor for use in the production of promising biosensor devices based on field-effect structures. The optimal process parameters are selected and the reproducibility of the process is studied. The uniformity, homogeneity, and elemental composition of the resulting film are studied. The structures based on ion-sensitive field-effect transistors fabricated using this tantalum oxide exhibit a near-threshold pH dependence (56 mV/pH) and stability in buffer solutions.