Ferroelectwc-semiconductor devices

Abstract

If a ferroelectric and a semiconductor material are placed in intimate contact, then the polarization state of the ferroelectric can be used to modify the electrical properties of the semiconductor. This effect has been used to build various prototypes of electrically adaptive resistors and transistors.The characteristics of these ferroelectric-semiconductor devices are reviewed in terms of the basic properties of the ferroelectric, the semiconductor and the interface between these two electrically active materials. It has been found that the method of fabrication strongly influences the electrical stability of the device. Specifically, a device that utilizes a thin-film ferroelectric layer on a bulk semiconductor material is much more stable than a device that consists of a thin-film semiconductor applied to a bulk ferroelectric material.Several types of three-and four-terminal ferroelectric-semiconductor devices are described. These devices have the very significant advantages of possessing non-volatile and analogue memory. Furthermore the memory state can be changed at MHz rates by electrically switching the ferroelectric. A very important potential application for ferroelectric-semiconductor devices is the microminiaturization of a large number of adaptive transistors in an integrated circuit.