Characterization of deposition process, microstructure and interfacial states of silicon dioxide film using tetraethylorthosilicate/O-2 with various dilution gases

We investigate gas-phase chemistry, and the properties of SiO2 films and th e Si/SiO2 interface formed by plasma chemical vapor deposition with tetraet hylorthosilicate (TEOS)/O-2 and various dilution gases. The N-2 dilution ga s produced a faster deposition rate than either He or Ar dilution gases. Ex cited nitrogen gas reacts with TEOS to form NH radicals, which enhance the dissociation of TEOS. Compared with He, the N-2 dilution gas suppressed the formation of OH radicals in the gas phase and reduced the concentration of SiH and SiOH in the SiO2 film. As a result, characteristics of the Si/SiO2 interface were improved. At the same deposition condition, the interface r oughness was almost identical at approximately two to three atomic layers r egardless of dilution gas. However, the increase in plasma power enhanced t he interface roughness to three to five atomic layers, which possibly incre ased the interface traps density. The P-b center decreased abruptly down to 1.1 x 10(11)/eV cm(2), and the interface characteristic improved when usin g the N-2 dilution gas. (C) 2001 The Electrochemical Society.