Vibrational Spectroscopic Study of the Interface of SiO2/Si(100) Fabricated by Highly Concentrated Ozone: Direct Evidence for Less Strained Si–O–Si Bond Angle

Abstract

The interface structure of SiO2/Si(100) synthesized with a highly concentrated ozone gas was analyzed by Fourier-transformed infrared absoption spectroscopy (FT-IR). The position of a transverse optical (TO) phonon peak of Si–O–Si asymmetric stretching vibration, which is a function of a Si–O–Si bond angle, remains constant at 1065 cm-1 within a ∼2 nm thickness of an ozone-oxide film. This result indicates that the thickness of structural transition layers at this interface where the Si–O–Si angle is distorted due to the stress at the interface is considerably limited, which is in contrast to a thermal oxide film on Si(100) showing the existence of structural transition layers.