REDUCTION OF MOBILE PT ION DENSITY IN SIO2 AND SI-SIO2 INTERFACE STATE DENSITY IN PT-DIFFUSED METAL-OXIDE-SEMICONDUCTOR STRUCTURES

Platinum diffusion into bipolar devices introduces mobile Pt ions into SiO2 films and causes the state density at the Si-SiO2 interface to i ncrease. Mobile Pt ions make the devices unstable and the increase in the interface state density causes enhancement of leakage current. MOS , metal-phosphosilicate glass-oxide-semiconductor (MGOS) and metal-sil icon nitride-oxide-semiconductor (MNOS) structures are fabricated on ( 111) and (100) substrates in order to investigate means of reducing th ese adverse effects induced by Pt diffusion. Mobile Pt ions, the inter face state density and the flat-band voltage for these structures are measured. The experimental results show that the MGOS structure with t he (100) oriented substrate is most beneficial in reducing the adverse effects of Pt-diffused devices.