Precise electrical evaluation of active oxides thickness and comparison with TEM measurements

In this paper we propose a new model to describe the quantum effects at the SiO2/Si interface of metal-oxide-semiconductor (MOS) devices. Using this m odel we developed a method to extract the thickness of thin oxides (in the range of 3-20 nm) from capacitance (C) as a function of voltage (V) measure ments, C(V). The results of our extraction are in good agreement with trans mission electron microscopy (TEM) measurements, within the accuracy of both techniques, while classical electrical methods are inadequate for a precis e evaluation of the oxide thickness. Moreover this new method is suitable f or in-line monitoring of oxide thickness in advanced MOS processes. (C) 200 1 Elsevier Science B.V. All rights reserved.