Infrared Spectroscopic Characterization Of Thermal Oxide SiO₂ On SiC

Silicon carbide (SiC) is a kind of semiconductor to be choiced for high-temperature, high-power, and high-frequency devices because of its large band gap. The possibility to grow thermal oxides on SiC gives significant advantages over other compound semiconductors and also makes it compatible with other silicon technologies. But there is a substantial evidence that some of the excess carbon released during thermal oxidation remains near the SiO₂/SiC interface and in the oxidation layer. These residual carbon complexes have been identified as the main reason that influenced some electronic properties of the SiO₂/SiC interface and the gate oxide itself. Many researchers have used different methods to raise the quality of SiO₂ layer and the interface characteristics SiO₂/SiC,in which secondary ion mass spectrometry (SIMS), X-ray photon spectroscopy (XPS) and C-V were used to character the surface of the oxide layer, the valence elements, the distribution and the changes of the interface after annealing. The C atoms and vacancies will not only affect the structure of SiO₂ layer, but also the oxide layer charges. By using infrared reflectance spectroscopy on the thermal oxidation of SiO₂/SiC oxygen, the reflection peaks of SiO₂/Si were studied after different annealing temperature to establish quality detection spectroscopic characterization hoping to be explored in the thermal oxidation process. In this paper, infrared reflectance spectra of the dry and wet thermal oxidation SiO₂ layer on the Si and 6H-SiC were analyzed of the preliminary view that in a few typical SiO₂ infrared reflectance signal, asymmetric stretching vibration (TO 1087 cm^-1) as the most valuable quality SiO₂ layer detection signal. The mechanism of the peak near 751cm^-1 is not clear yet.