Electrical And Optical Characterization Of Sionc Dielectric Thin Film Deposited By Polymer-Source Chemical Vapor Deposition

The electro-optical properties of SiONC dielectric thin films deposited by polymer-source chemical vapor deposition using an organosilane precursor has been investigated as a function of oxygen concentration in the films. SiONC thin films were characterized using capacitance-voltage (C-V), conductance-voltage (G-V), ellipsometry, and ultraviolet visible (UV-Vis) photospectroscopy. These measurements showed that the electro-optical properties of the films are greatly influenced by the atomic concentration of oxygen. The high frequency C-V measurement revealed a nearly ideal metal-oxide-semiconductor (MOS) structure behavior at high atomic concentration of oxygen (35 at. %). A relative dielectric constant as high as 6 is obtained at 10 kHz for samples with about 5 at. % of oxygen, which corresponds to high-k dielectric material. The interface trap density extracted from G-V measurement using Hill-Coleman method is as low as 3.2x10(10) (cm(-2) eV(-1)), making these films a viable high-k dielectric alternative to SiO2 and SiON in MOS devices. The refractive index measured by ellipsometry at a wavelength of 632.8 nm shows a linear variation with atomic concentration of oxygen from 1.58 to 1.69. The optical energy band gap extracted from UV-Vis absorption spectra was found to vary between 4.40 and 5.25 eV. (c) 2007 American Institute of Physics.