Ultra thin oxide characterization with MBE deposited poly silicon

In this paper we present a new approach to determine D_it and Q_BD of the Si-SiO₂ interface by using a highly doped Poly-Si electrode deposited by molecular beam epitaxy (MBE) where no Hydrogen is present in the depositing ambient. This allows the optimization of the inherent surface state density of different gate dielectrics without unintentional H-annealing and in addition combines the advantages of the standard techniques for D_it determination: the commercially available techniques, e.g. Quantox^TM, and the conventional Poly-Si electrode method were the Poly-Si is deposited by means of chemical vapour deposition (CVD). It appears that one can direct compare the D_it of the presented approach with the D_it measured with surface photo voltage (SPV) by Quantox^TM. On the other hand the conventional CVD Poly-Si electrode measurements can be simulated by subsequent annealing of the MBE Poly-Si electrode in a controlled H-ambient introducing Hydrogen to the interface. Therefore the gap between the commercially available measurements and the conventional Poly-Si method is closed and therefore a deeper understanding of the "real" interface state density and the break down behaviour even under "production condition" can be obtained.