DIELECTRICS FOR FIELD-EFFECT TECHNOLOGY

The availability of stable MOS gate systems and high density storage capacitors is an essential requirement for the development of the field effect storage technology, For standard MOSFET gates this role has been fulfilled by SiO2 grown by thermal oxidation of the Si substrate, Improved insight into the properties of the Si/SiO2 system and perfection of its growth technology will secure its role in Si MOSFET memories for the future. For charge storage application the stability requirements are less demanding, However, here SiO2 is not able to provide sufficient capacity. In this case higher dielectric constant materials (Si3N4 or Ta2O5) have to take over, Particularly attractive appears the use of ferroelectrics. These dielectric materials not only offer a high dielectric constant, but also the perspective of providing non-volatile storage in capacitor structures.