ISSN:
1057-9257
Keywords:
silicon dioxide
;
thin films
;
excimer laser
;
chemical vapour deposition (CVD)
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Physics
Notes:
Silicon oxide films have been deposited on silicon wafers at low temperature by irradiation of the substrates with an ArF (λ = 193 nm) excimer laser beam in a SiH4 and N2O atmosphere. A systematic study of the growth rate and properties of the films as a function of the processing parameters (gas composition, substrate temperature, laser pulse energy, pulse repetition rate, total pressure and gas flow rate) has been performed. The process is photolytically activated in the gas phase and the diffusion of photodecomposed precursor species towards the surface plays an important limiting role. The N2O/SiH4 ratio mainly controls the film composition; for ratios above 40, stoichiometric silica may be obtained, as confirmed by Rutherford backscattering (RBS) measurements. The role of the surface temperature in the growth kinetics is not critical, so that deposition of films is possible down to substrate temperatures as low as 70°C. Nevertheless, the density of the films varies greatly with the substrate temperature. The fact that no Si(SINGLE BOND)H vibration was detected with Fourier transform infrared (FTIR) spectrophotometry is surprising, since hydrogen incorporation is a very typical phenomenon encountered in most silane systems. This effect is probably associated with the ultraviolet photon irradiation of the adsorbed species and the film as it grows, thus breaking bonds and affecting the bond structure of the film.
Additional Material:
14 Ill.
Type of Medium:
Electronic Resource
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