The Improvement of the Characteristics of Liquid Phase-Deposited Silicon
Dioxide/Silicon Interface

Abstract

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.