  The formation of super-Earths is strongly linked to the structure of the
protoplanetary disc, which determines growth and migration. In the pebble
accretion scenario, planets grow to the pebble isolation mass, at which the
planet carves a small gap in the gas disc halting the pebble flux and thus its
growth. The pebble isolation mass scales with the disc's aspect ratio, which
directly depends on the disc structure. I compare the growth of super-Earths in
viscously heated discs and discs purely heated by the central star with
super-Earth observations. This allows two formation pathways of super-Earths to
be distinguished in the inner systems. Planets growing within 1 Myr in the
viscously heated inner disc reach pebble isolation masses that correspond
directly to the inferred masses of the Kepler observations for systems that
feature planets in resonance or not in resonance. However, to explain the
period ratio distribution of Kepler planets -- where most Kepler planet pairs
are not in mean motion resonance configurations -- a fraction of these resonant
chains has to be broken. In case the planets are born early in a viscously
heated disc, these resonant chains thus have to be broken without planetary
mergers. If super-Earths form either late or in purely passive discs, the
pebble isolation mass is too small to explain the Kepler observations, implying
that planetary mergers are important for the final system architecture.
Resonant planetary systems thus have to experience mergers already during the
gas disc phase, so the planets can get trapped in resonance after reaching 5-10
Earth masses. In case instabilities are dominating the system architecture, the
systems should not be flat with mutually inclined orbits. This implies that
future observations of planetary systems with RV and transits could distinguish
between these two formation channels of super-Earth. (abridged)
