Process Diagnostics For Remote Plasma-Enhanced Chemicalvapor Deposition (Pecvd) Of Silicon Nitrides

Hydrogenated silicon nitride films were deposited in a remote plasma reactor using a plasmaexcited NH3/He mixture, and with downstream injection of SiH4. An electrically biased grid placed between the plasma tube and the deposition region was used to control the extent of the plasma afterglow into the deposition region. In situ monitoring by mass spectrometry (MS) indicated that the Si content of the film was increased when charged species were transported from the plasma region to the deposition region of the chamber, and that the properties of the resulting films could be understood in terms of two different deposition pathways, driven respectively by neutral, and a combination of neutral and charged precursor species.