Speaker
Steven Worm
(STFC - Rutherford Appleton Lab. (GB))
Description
CMOS Monolithic Active Pixel Sensors (MAPS) are starting to be investigated for particle
physics experiments. In order to make MAPS the solution of choice for more experiments, we
are developing sensors able to withstand high levels of radiation such as those required by
the extremely harsh environments found in the Large Hadron Collider (LHC) experiments. A
very rad-hard MAPS will also provide benefit in terms of imaging speed. CMOS MAPS designed
in a deep-implant "INMAPS" process are flexible in design and have been shown to work for
experiments such as Alice at the LHC. High-resistivity substrates, i.e. of order one
kOhm-cm, are used to provide a depleted region for charge collection, even with the small
voltages normally available in CMOS. An electric field is present in the depletion region,
thus speeding up charge collection and reducing the spread of charge between pixels. This
in turn is beneficial for the detection efficiency as the average signal over noise ratio
for a signal pixel is increased. The reduced charge collection time also means the sensors
is less affected by the lattice damage generated by Non Ionising Energy Loss (NIEL). I will
present the status of the HR-CMOS work at RAL, and plans for the future.
Author
Steven Worm
(STFC - Rutherford Appleton Lab. (GB))
