HYDROGEN INCORPORATION IN SILICON-OXIDE FILMS DEPOSITED BY ARF LASER-INDUCED CHEMICAL-VAPOR-DEPOSITION

An evaluation of the hydrogen content present in silicon oxide thin fi lms obtained from a gas mixture of N2O and SiH4 by ArF excimer laser-i nduced chemical vapor deposition in a parallel configuration reactor i s 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 bended hydrogen in the matrix and the total quantity of hydrogen atoms, the films were respectively analyze d by Fourier-transform infrared (FTIR) spectroscopy and elastic recoil detection analysis (ERDA). Additional analyses by ellipsometry and Ru therford backscattering spectrometry (RBS) were performed. As the sila ne quantity in the gas mixture increases, the RBS measurements reveal a continuously decreasing film stoichiometry towards suboxides. Simult aneously, a dramatical increase in the quantity of Si-H bonds is obser ved in the FTIR spectra, but an unexpected decrease in the total numbe r of hydrogen atoms is detected by ERDA. The total hydrogen content co rrelates with the film growth rate, while the Si-H bond incorporation correlates with the SiH4 content in the gas mixture.