  We study multielectron bubble phases in the $N=2$ and $N=3$ Landau levels in
a high mobility GaAs/AlGaAs sample. We found that the longitudinal
magnetoresistance versus temperature curves in the multielectron bubble region
exhibit sharp peaks, irrespective of the Landau level index. We associate these
peaks with an enhanced scattering caused by thermally fluctuating domains of a
bubble phase and a uniform uncorrelated electron liquid at the onset of the
bubble phases. Within the $N=3$ Landau level, onset temperatures of
three-electron and two-electron bubbles exhibit linear trends with respect to
the filling factor; the onset temperatures of three-electron bubbles are
systematically higher than those of two-electron bubbles. Furthermore, onset
temperatures of the two-electron bubble phases across $N=2$ and $N=3$ Landau
levels are similar, but exhibit an offset. This offset and the dominant nature
of the three-electron bubbles in the $N=3$ Landau level reveals the role of the
short-range part of the electron-electron interaction in the formation of the
bubbles.
