Hydrogen incorporation in silicon oxide films deposited by ArF laser-induced chemical vapor deposition

Abstract An evaluation of the hydrogen content present in silicon oxide thin films obtained from a gas mixture of N 2 O and SiH 4 by ArF excimer laser-induced chemical vapor deposition in a parallel configuration reactor is presented. By tuning the oxidant-monosilane ratio, a complete set of films ranging from hydrogen-rich silicon suboxides to silicon dioxide were deposited. To evaluate the bonded hydrogen in the matrix and the total quantity of hydrogen atoms, the films were respectively analyzed by Fourier-transform infrared (FTIR) spectroscopy and elastic recoil detection analysis (ERDA). Additional analyses by ellipsometry and Rutherford backscattering spectrometry (RBS) were performed. As the silane quantity in the gas mixture increases, the RBS measurements reveal a continuously decreasing film stoichiometry towards suboxides. Simultaneously, a dramatical increase in the quantity of SiH bonds is observed in the FTIR spectra, but an unexpected decrease in the total number of hydrogen atoms is detected by ERDA. The total hydrogen content correlates with the film growth rate, while the SiH bond incorporation correlates with the SiH 4 content in the gas mixture.