  We present the results of the characterization of silicon pixel modules
employing n-in-p planar sensors with an active thickness of 150
$\mathrm{\mu}$m, produced at MPP/HLL, and 100-200 $\mathrm{\mu}$m thin active
edge sensor devices, produced at VTT in Finland. These thin sensors are
designed as candidates for the ATLAS pixel detector upgrade to be operated at
the HL-LHC, as they ensure radiation hardness at high fluences. They are
interconnected to the ATLAS FE-I3 and FE-I4 read-out chips. Moreover, the
n-in-p technology only requires a single side processing and thereby it is a
cost-effective alternative to the n-in-n pixel technology presently employed in
the LHC experiments. High precision beam test measurements of the hit
efficiency have been performed on these devices both at the CERN SpS and at
DESY, Hamburg. We studied the behavior of these sensors at different bias
voltages and different beam incident angles up to the maximum one expected for
the new Insertable B-Layer of ATLAS and for HL-LHC detectors. Results obtained
with 150 $\mathrm{\mu}$m thin sensors, assembled with the new ATLAS FE-I4 chip
and irradiated up to a fluence of
4$\times$10$^{15}\mathrm{n}_{\mathrm{eq}}/\mathrm{cm}^2$, show that they are
excellent candidates for larger radii of the silicon pixel tracker in the
upgrade of the ATLAS detector at HL-LHC. In addition, the active edge
technology of the VTT devices maximizes the active area of the sensor and
reduces the material budget to suit the requirements for the innermost layers.
The edge pixel performance of VTT modules has been investigated at beam test
experiments and the analysis after irradiation up to a fluence of
5$\times$10$^{15}\mathrm{n}_{\mathrm{eq}}/\mathrm{cm}^2$ has been performed
using radioactive sources in the laboratory.
