RELIABILITY OF NANO-METER THICK MULTI-LAYER DIELECTRIC FILMS ON POLY-CRYSTALLINE SILICON.

The use of a double-layer dielectric film (SiO//2/Si//3N//4) on poly-Si is proposed as a way to achieve the reduced thickness films needed to scale down VLSIs. The oxidation of Si//3N//4 reduces leakage current and defect density. It is shown that a double-layer film with a thinner top oxide layer is harder to break down, so, the thickness of the top oxide layer must be reduced in order to increase the reliability of double-layer dielectrics. Moreover, there are no edge effects on the reliability of double-layer dielectric films due to the patterned poly-Si electrode. These results, confirm that SiO//2/Si//3N//4 is a highly reliable nanometer-thick dielectric for use on poly-Si.