Electrical reliability aspects of through the gate implanted MOS structures with thin oxides

The effect of through the gate implantation (TGI) on MOS devices with oxide thicknesses of 3.3, 4.0, and 20 nm is studied, utilizing constant voltage stress tests and a substrate hot electron (SHE) injection technique. For 3.3 and 4.0 nm thick oxides, a dependence of time to breakdown on TGI dose is detected which, for 3.3 nm samples, diminishes with increasing test voltage. SHE injection measurements show a TGI induced increase in intrinsic electron trap density and also an increase in trap generation rate during sample stressing. A change of electron trap generation dynamics seems to be the main cause for oxide weakening due to TGI.