Ferroelectric-enhanced tantalum pentoxide for dielectric material applications in CMOS devices

摘要

In insulated-gate, field effect transistor (IGFET) devices fabricated in integrated circuits, the scaling down of the dimensions of the devices has resulted in structures with dimensions are so small that reproducibility of parameters can become problematic. Specifically, the gate dielectric, typically silicon nitride, silicon oxide or silicon nitride, of a gate structure is nearing the point where the required thickness of the gate dielectric to provide the selected electric field in the channel region is implemented with a few to several atomic layers. In order to improve parameter reproducibility, a dielectric material, such TaO₅ or a ferroelectric material, is used as a gate dielectric. TaO₅ and the ferroelectric materials have a dielectric constant an order of magnitude higher than the material typically used in the past. Using these materials, the gate dielectric can be proportionately thicker, thereby improving the parameter reproducibility.