The Improvement of the Characteristics of Liquid Phase-Deposited Silicon Dioxide/Silicon Interface
Liquid phase deposition (LPD) is the method to deposit SiO2 films on the substrates at room temperature in the super-saturated fluorosilicic acid (H2SiF6) solution. When the SiO2 films are directly deposited on the Si substrates, which are treated with diluted HF to remove the native oxide, the characteristics of the the SiO2/Si interface are poor, because the surface Si atoms are terminated and covered with H atoms. Low temperature (30—500°C) annealing in O2 was found to be effective to improve the interface characteristics, and also the breakdown characteristics. This low temperature annealing in O2 ambient is useful without losing the merit of low temperature process in the liquid-phase deposition method, when the deposited SiO2 films are used as the gate insulators in Si MOS FETs.