Characterization of Deposition Process, Microstructure and Interfacial States of Silicon Dioxide Film Using Tetraethylorthosilicate/ O 2 with Various Dilution Gases

Abstract

We investigate gas-phase chemistry, and the properties of films and the interface formed by plasma chemical vapor deposition with tetraethylorthosilicate and various dilution gases. The dilution gas produced a faster deposition rate than either He or Ar dilution gases. Excited nitrogen gas reacts with TEOS to form NH radicals, which enhance the dissociation of TEOS. Compared with He, the dilution gas suppressed the formation of OH radicals in the gas phase and reduced the concentration of SiH and SiOH in the film. As a result, characteristics of the interface were improved. At the same deposition condition, the interface roughness was almost identical at approximately two to three atomic layers regardless of dilution gas. However, the increase in plasma power enhanced the interface roughness to three to five atomic layers, which possibly increased the interface traps density. The center decreased abruptly down to and the interface characteristic improved when using the dilution gas. © 2001 The Electrochemical Society. All rights reserved.