  In this study, we investigated the influence of silicon oxide roughness
produced from the gas precursor monosilane (SiH$_4$) and the silicon-organic
precursor tetraethoxysilane (TEOS) on the optical qualities of a distributed
Bragg reflector (DBR). A significant influence of the precursors from which
SiOx is deposited on the optical qualities of DBR mirrors is demonstrated in
this study. It has been shown experimentally that a mirror produced from the
TEOS precursor is endowed with better qualities than a mirror produced using
SiH4, that is, the reflectivity increased by 20% and optical losses decreased
by half. The roughness average (Ra) of the SiN$_x$/SiO$_x$ / (TEOS) mirror
surface decreased by a factor of five compared to that of the SiN$_x$/SiO$_x$ /
(SiH4) mirror
