  A quantum dot fabricated by scanning probe oxidation lithography on a p-type,
C-doped GaAs/AlGaAs heterostructure is investigated by low temperature
electrical conductance measurements. Clear Coulomb blockade oscillations are
observed and analyzed in terms of sequential tunneling through the
single-particle levels of the dot at T_hole = 185 mK. The charging energies as
large as 2 meV evaluated from Coulomb diamond measurements together with the
well resolved single-hole excited state lines in the charge stability diagram
indicate that the dot is operated with a small number of confined particles
close to the ultimate single-hole regime.
