TY - JOUR
T1 - N, NH, and NH2 radical densities in a remote Ar-NH3-SiH4 plasma and their role in silicon nitride deposition
AU - Oever, van den, P.J.
AU - Helden, van, J.H.
AU - Hemmen, van, J.L.
AU - Engeln, R.A.H.
AU - Schram, D.C.
AU - Sanden, van de, M.C.M.
AU - Kessels, W.M.M.
PY - 2006
Y1 - 2006
N2 - The densities of N, NH, and NH2 radicals in a remote Ar-NH3-SiH4 plasma used for high-rate silicon nitride deposition were investigated for different gas mixts. and plasma settings using cavity ringdown absorption spectroscopy and threshold ionization mass spectrometry. For typical deposition conditions, the N, NH, and NH2 radical densities are on the order of 1012 cm-3 and the trends with NH3 flow, SiH4 flow, and plasma source current are reported. We present a feasible reaction pathway for the prodn. and loss of the NHx radicals that is consistent with the exptl. results. Furthermore, mass spectrometry revealed that the consumption of NH3 was typically 40%, while it was over 80% for SiH4. On the basis of the measured N densities we deduced the recombination and sticking coeff. for N radicals on a silicon nitride film. Using this sticking coeff. and reported surface reaction probabilities of NH and NH2 radicals, we conclude that N and NH2 radicals are mainly responsible for the N incorporation in the silicon nitride film, while Si atoms are most likely brought to the surface in the form of SiHx radicals. [on SciFinder (R)]
AB - The densities of N, NH, and NH2 radicals in a remote Ar-NH3-SiH4 plasma used for high-rate silicon nitride deposition were investigated for different gas mixts. and plasma settings using cavity ringdown absorption spectroscopy and threshold ionization mass spectrometry. For typical deposition conditions, the N, NH, and NH2 radical densities are on the order of 1012 cm-3 and the trends with NH3 flow, SiH4 flow, and plasma source current are reported. We present a feasible reaction pathway for the prodn. and loss of the NHx radicals that is consistent with the exptl. results. Furthermore, mass spectrometry revealed that the consumption of NH3 was typically 40%, while it was over 80% for SiH4. On the basis of the measured N densities we deduced the recombination and sticking coeff. for N radicals on a silicon nitride film. Using this sticking coeff. and reported surface reaction probabilities of NH and NH2 radicals, we conclude that N and NH2 radicals are mainly responsible for the N incorporation in the silicon nitride film, while Si atoms are most likely brought to the surface in the form of SiHx radicals. [on SciFinder (R)]
U2 - 10.1063/1.2358330
DO - 10.1063/1.2358330
M3 - Article
SN - 0021-8979
VL - 100
SP - 093303-1/10
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 9
M1 - 093303
ER -