  In supersymmetric models with Dirac neutrinos, the lightest sneutrino can be
an excellent thermal dark matter candidate when the soft sneutrino trilinear
parameter is large. We focus on scenarios where the mass of the mixed sneutrino
is of the order of GeV and sensitivity of dark matter direct detection is weak.
We investigate phenomenological constraints on the model parameter space
including the vacuum stability bound. We show that the allowed regions can be
explored by measuring Higgs boson properties at future collider experiments.
