RELIABILITY AND CHARACTERIZATION OF ULTRA-THIN DIELECTRIC FILMS USINGFOWLER-NORDHEIM INJECTION EXPERIMENT

Thin insulators, SiO2 or oxynitrides, in the range of 6-8 nm are requi red for the generation of MOS devices that is now under development. T hese devices with gate dielectrics in such a thickness range exhibit r eliability problems such as wearout of transistors in RAM's and reduce d life-times for tunnelling devices that are due to hot carrier degrad ation. Furthermore, the search for higher circuit yield have motivated an intense work for reducing the defectivity levels. For both lifetim e and defectivity issues, Fowler-Nordheim (F-N) injection has been ext ensively studied (1). Examples illustrating the interest of F-N for th e characterization of thin 6-8 nm dielectrics are presented here in th e context of nitridation process evaluation and in that of the monitor ing of the gate oxide quality in its manufacturing environment.