Electrical Characteristics of Tantalum Pentoxide‐Silicon Dioxide‐Silicon Structures

Abstract

Electrical characteristics for metal‐tantalum pentoxide‐silicon dioxide‐silicon structures are described. The interface charge density and the surface‐state density are measured to determine the interface properties. By optimizing each insulator thickness, the interface charge density can be reduced to as low as at flatband. The surface‐state density of can be obtained near the midgap by inserting a 25 nm thickness of . It is indicated that the interface charge density variation with each insulator thickness can be explained by the charge compensation mechanism between the positive charge at interface and the negative charge at interface. It is found that the negative charge localized at interface gradually decreases and that the dielectric constant for deposited on monotonically increases with the underlying layer thickness.