STRUCTURAL AND ELECTRICAL PROPERTIES OF THIN RF SPUTTERED Ta_2O_5

摘要

Elemental composition, chemical bonding and some electrical properties of rf sputtered tantalum oxide with thickness 10 - 70nm depending on process parameters have been investigated. The results indicate that tantalum oxide could be obtained by rf sputtering even in gas mixture with N_c = 2.5%, but 10% oxygen content, however, is beneficial for obtaining of stoichiometric and homogeneous Ta_2O_5 with an abrupt interface transition region. AES and XPS experiments show that the layers stoichiometry does not depend on their thickness and on the substrate temperature in the investigated ranges. Additionally the electrical measurements strongly suggest that Ta_2O_5 layers suitable for submicron application (with high dielectric constant and low fixed oxide charge) can be obtained only at T_8 = 493K.