Origin of area selective plasma enhanced chemical vapor deposition of microcrystalline silicon

Ghewa Akiki (1) , Mathieu Frégnaux (2) , Ileana Florea (1) , Pavel Bulkin (1) , Dmitri Daineka (1) , Sergej Filonovich (3) , Muriel Bouttemy (2) , Erik Johnson (1)

1 LPICM - Laboratoire de physique des interfaces et des couches minces [Palaiseau]
2 ILV - Institut Lavoisier de Versailles
3 TOTAL S.A.

Plasma Enhanced Chemical Vapor Deposition of silicon from SiF4/H2/Ar gas mixture is observed on a SiOxNy surface, while under the same plasma conditions, silicon films do not grow on AlOx nor Al surfaces. Transmission electron microscopy confirms that the silicon deposited on SiOxNy has a microcrystalline structure. After the plasma process, fluorine is detected in abundance on the AlOx surface by X-ray photoelectron spectroscopy and energy dispersive X-ray chemical analyses. This suggests that Al-F bonds are formed on this surface, blocking any deposition of silicon on it. In-situ ellipsometry studies show that deposition can be initiated on AlOx surfaces by increasing the temperature of the electrodes or increasing the RF plasma power, leading to a loss of selectivity.

Domaines: Plasmas

Ghewa Akiki, Mathieu Frégnaux, Ileana Florea, Pavel Bulkin, Dmitri Daineka, et al.. Origin of area selective plasma enhanced chemical vapor deposition of microcrystalline silicon. Journal of Vacuum Science & Technology A, 2021, 39 (1), pp.013201. ⟨10.1116/6.0000653⟩. ⟨hal-03060642⟩