  The magnetic order associated with the degree of freedom of spin in
two-dimensional (2D) materials is subjected to intense investigation because of
its potential application in 2D spintronics and valley-related magnetic
phenomena. We report here a bottom-up strategy using molecular beam epitaxy to
grow and dope large-area (cm$^2$) few-layer MoSe$_2$ with Mn as a magnetic
dopant. High-quality Mn-doped MoSe$_2$ layers are obtained for Mn content of
less than 5 % (atomic). When increasing the Mn content above 5 % we observe a
clear transition from layer-by-layer to cluster growth. Magnetic measurements
involving a transfer process of the cm$^2$-large doped layers on
100-micron-thick silicon substrate, show plausible proof of high-temperature
ferromagnetism of 1 % and 10 % Mn-doped MoSe$_2$. Although we could not point
to a correlation between magnetic and electrical properties, we demonstrate
that the transfer process described in this report permits to achieve
conventional electrical and magnetic measurements on the doped layers
transferred on any substrate. Therefore, this study provides a promising route
to characterize stable ferromagnetic 2D layers, which is broadening the current
start-of-the-art of 2D materials-based applications.
