Silicon nitride deposited by inductively coupled plasma using dichlorosilane and ammonia

Low temperature–low hydrogen content silicon nitrides thin films deposited by PECVD using dichlorosilane and ammonia mixtures

“…index decrease with the increase in the ammonia concentration. This behavior is similar to that observed for silicon nitride films deposited by LPCVD and inductively coupled plasma-CVD (ICP-CVD) from dichlorosilane and ammonia, although our deposition rates were relatively higher (in the range from 12 to 20 nm/min) [11,20]. The decrease in the deposition rate as R increases indicates that under the used experimental conditions the growth of these films is limited by the partial pressure of the Si precursor gas (dichlorosilane), which decreases with NH 3 dilution.…”

“…Fig. 4 shows the spectra of films deposited at 20, 30, 60 and 80 W. As can be seen from this figure, the emission spectrum for the lowest value of RF power (20 W) shows predominantly a continuum band extending from 250 to 425 nm, and other lines in 20 the region from 410 to 500 nm. The continuous band can be identified as the superposition of two well-known continuums; one due to emission from H 2 molecules and another due to SiCl 2 molecules and SiH x Cl y species [31,32].…”

“…2 shows IR absorption spectra for films deposited under the different ammonia/dichlorosilane ratios. The spectra of samples deposited with R P 2.5 show the principal absorption bands related to Si-N stretching and breathing vibration modes, which are centered between 850 and 890 cm À1 , and 480 and 500 cm À1 , respectively, and peaks located at 3346 cm À1 and 1170 cm À1 , which can be associated to N-H stretching and bending modes, respectively [19,20,[24][25][26][27][28]. The increase in the incorporation of N-H bonds as R increases is well expected since the concentration of NH x , NH Ã…”

“…This requirement has widespread the use of diverse plasma enhanced chemical vapor deposition (PECVD) processes for depositing at low temperatures high quality silicon nitride films, such as electron cyclotron resonance [17,18], remote-PECVD [5,14,19], inductively coupled (IC) PECVD [16,20], and the conventional parallel plate-capacitive coupled PECVD [6,10,12,[21][22][23][24]. It should be mentioned that the latter PECVD version has continuously been of great interest because it has been largely studied and scaled-up to mass production dimensions in the production lines [21,25].…”

“…The use of halogenated silicon precursors like dichlorosilane (SiH 2 Cl 2 ), which contains less H atoms per Si atom than the SiH 4 molecule, has been proposed recently as a good alternative to reduce hydrogen incorporation in PECVD films deposited at 350-380°C, without reducing significantly the deposition rates compared with the corresponding thermal CVD process [11,12,20]. However, the reduction of substrate temperatures below 300°C, maintaining or even improving the physical and chemical properties of the silicon nitride films is a permanent challenge for materials science researchers.…”