Characterization of SiO2 Films Deposited by Pyrolysis of Tetraethylorthosilicate (TEOS)

Deposition rate, thickness unriformity and step coverage of SiO2 films deposited on Si substrates by pyrolysis of TEOS have been studied as a function of process parameters: temperature, pressure, and gas flow. Oxide films with iformrities of ±1% on 100-mm. wafers and step coverage of 76% on 1 μm wide and deep trenches have been obtained. The electrical characterization of TEOS-SiO2 films deposited on single crystal Si shows a charge density of about 10¹¹ cm^-2, a surface state density at Si midgap lower than 10¹⁰ eV^-1 cm^-2, a Si/SiO2 barrier height of 2.6 eV and a breakdown field strength from 7.5 to 9 MV/cm. TEOS-SiO2 films deposited on POCl3 doped poly-Si show insulation properties comparable to that of SiO2 films grown at 1100°C.