Activation energies in chemical vapour deposition kinetics of SiO2 films using TEOS chemistry

Development of a kinetic model for the moderate temperature chemical vapor deposition of SiO2 films from tetraethyl orthosilicate and oxygen

“…This means that for the conditions tested, the minimum temperature for SiO 2 deposition is 300 C. For the experiments corresponding to the SP temperatures between 400 and 500 C, Figure 6 confirms that the deposition rate first increases with temperature up to 360-380 C and then decreases. This behavior is characteristic of the existence of two sets of chemical reactions, with probably a rather direct contribution of TEOS in the first temperature range, followed by a strong contribution of intermediate species above 380 C. For the 350-500 C temperature range, Pavelescu et al 19 obtained a decreasing evolution of the deposition rate, probably due to the position of their substrates on a row in an isothermal zone as previously mentioned. Their results are then coherent with ours obtained in the zone of decreasing deposition rate.…”

“…As said in Introduction, Pavelescu et al, 19 processed SiO 2 films from TEOS/O 2 mixtures in a hot wall CVD reactor at atmospheric pressure between 350 and 800 C. The obtained Arrhenius plot reveals two deposition rate regimes, noticeably Figure 6. Evolution of the logarithm of the deposition rates of SiO 2 as a function of the inverse of the surface temperature for the experiments performed at the four SP temperatures.…”

“…Most of the deposition rates vary between 0.5 and 10 nm min −1 ; that is, in the same range as those reported in Pavelescu publication. 19 They are strictly increasing for the 350 C SP temperature, whereas they increase sharply and then slowly decrease for the other SP temperatures. Figure 6 presents the experimentally obtained deposition rates as a function of the inverse of the substrate temperature, for the four thermal profiles studied.…”

“…An activation energy of 161.3 kJ mol −1 is deduced from these points. This value cannot be compared with those of the literature, in particular with those of Pavelescu et al, 19 because the authors used deposition rate results obtained from samples positioned on a row in isothermal zones, that is, from gas phases with variable composition containing partly decomposed TEOS. Their reported activation energies are representative of numerous chemical reactions, therefore they are apparent.…”

“…18 In this work, it is reported that ethanal, methanal, water, and CO 2 are the resulting decomposition by-products. Pavelescu et al deposited silica films in a tubular reactor from TEOS and O 2 at atmospheric pressure in the temperature range 350-850 C. 19 The obtained deposition rates vary between 2 and 10 nm min −1 . They first decrease with increasing temperature from 350 to 500 C and then increase above 500 C. Konakov et al modeled SiO 2 deposition from TEOS/O 2 in a microreactor under atmospheric pressure between 300 and 800 C. 20 They used the chemical mechanisms and kinetic data published by Coltrin et al for SiO 2 deposition from TEOS pyrolysis at low pressure between 600 and 800 C, 21 obtained from quantum chemistry calculations.…”