Atomic layer deposition of zirconium silicate films using zirconium tetra-tert-butoxide and silicon tetrachloride

Abstract

A new precursor combination (SiCl4 and Zr((OC4H9)-C-t)(4)) was used to deposit Zr silicate with Zr((OC4H9)-C-t)(4) as a zirconium source and oxygen source at the same time. SiCl4 and Zr((OC4H9)-C-t)(4) have higher vapor pressures than their counterpart, ZrCl4 and tetra-n-butyl orthosilicate (TBOS), and it was expected that the cycle time would be shorter. The deposition temperature of the new combination was about 150degreesC lower than that of ZrCl4 and TBOS. The film was zirconium rich while it was silicon rich with ZrCl4 and TBOS. Growth rate (nm/cycle), composition ratio [Zr/(Zr+Si)], and chlorine impurity were decreased with increasing deposition temperature from 125 to 225 degreesC. The composition ratio of the film deposited at 225 degreesC was 0.53 and the chlorine content was about 0.4 at. %. No carbon was detected by x-ray photoelectron spectroscopy. (C) 2003 American Vacuum Society.