  In this work, we present the results of simulations carried out for N2-H2
capacitively coupled radio-frequency discharges, running at low pressure
(0.3-0.9 mbar), low power (5-20 W), and for amounts of H2 up to 5 pct.
Simulations are performed using a hybrid code that couples a two-dimensional
time-dependent fluid module, describing the dynamics of the charged particles
in the discharge, to a zero-dimensional kinetic module, that solves the
Boltzmann equation and describes the production and destruction of neutral
species. The model accounts for the production of several vibrationally and
electronic excited states, and contains a detailed surface chemistry that
includes recombination processes and the production of NHx molecules. The
results obtained highlight the relevance of the interactions between plasma and
surface, given the role of the secondary electron emission in the electrical
parameters of the discharge and the critical importance of the surface
production of ammonia to the neutral and ionic chemistry of the discharge.
