  We argue that the superpartner of the Dirac right-handed neutrino is a prime
candidate for dark matter created from a 'mattergenesis' mechanism. We show
that due to the smallness of the Yukawa couplings, a right-handed sneutrino
density created in the early Universe would not be erased by annihilations,
which remain out of thermal equilibrium. It would also not be drowned by a
later, additional production of right-handed sneutrinos, as the relic density
of the non-thermal right-handed sneutrinos is found to be generally negligible
compared to the observed dark matter density. Mild constraints on sneutrino
masses and trilinear SUSY-breaking couplings are obtained. Possible
mattergenesis scenarios are also mentioned
