The Hydrogen Content and Properties of SiO2 Films Deposited from Tetraethoxysilane at 27 MHz in Various Gas Mixtures

The deposition of films from tetraethoxysilane (TEOS) is investigated in gas mixtures containing either a large amount of oxygen or Ar. It is shown that films with good insulating properties can be deposited from both mixtures. In Ar/TEOS mixtures, films with C content below 1% have been obtained. In the case of oxygen, the rate must be kept low at low temperature to allow for the disappearance of hydrogen (water) from the film, for example, in our system, at 280°C below 12 nm/min. The dependence of the deposition rate on the temperature, dwell time, and partial pressure of TEOS are shown. Variation of the pressure (at constant flow rate and pumping speed) upon ignition of the plasma in the oxygen and Ar system are different, as well as the dependencies of the deposition rate on temperature. Possible reasons are discussed.