Speaker
Description
Summary
While CMOS processes are cost-efficient and commercially available, they have not yet been used to produce radiation-hard sensors. So-called HV CMOS processes combine a slightly higher resistivity p-type substrate with deep n-wells and allow the combination of a drift-based electron-collecting sensor with active cuircit components. Achievable depletion depths are in the order of 10-20 um.
This allows for novel sensor concepts such as having the first amplifier (and more electronics if desired) directly in a (very small) pixel sensor cell. Due to the low input capacitance of the small pixel, the noise contribution is very small and the signal-to-noise ratio is superb in spite of the rather shallow depletion zone and signal. These small pixel cells can then combined to form virtual strips or larger pixels which match already existing readout electronics chips, e.g. Beetle or FE-I4. Analogue hit encoding can yield improved resolution compared to the readout-chip pitch.
The presentation will introduce the concept, present preliminary results obtained with first test chips and summarize the sensor design of a combined active strip/pixel sensor chip which was submitted in November and will be available for testing by end of March.
In addition, an outlook will be given on the prospects and possible benefits of going to even smaller CMOS feature sizes. Furthermore, advantages and drawbacks of active CMOS sensors will be compared to drift-based CMOS MAPS concepts.
