Thin Dielectric Behavior and Boron Penetration under High Temperature H2 SEG Prebake

During selective epitaxial Si growth the wafers are exposed to a H2 rich atmosphere. The impact of high temperature hydrogen prebake, typical of selective Si epitaxial processes, on thin dielectrics is investigated. A prebake temperature range of 850°C to 1000°C was studied. MOS capacitors with n+ and p+ gates and 8.5nm oxides and plasma nitrided oxides are examined. For p+ MOS with non-nitrided gate oxides massive boron penetration occurs. In contrast, nitrided oxides are found to be highly immune to hydrogen induced boron penetration and exhibit a low interface state density for either n+ or p+ gate samples.