A novel monolithic active pixel sensor for charged particle tracking has be
en designed and fabricated in a standard CMOS technology. The device archit
ecture is identical to a CMOS camera. recently being proposed as an alterna
tive to CCD sensors for visible light imaging. The partially depleted thin
epitaxial silicon layer is used as a sensitive detector volume. The sensor
is a photodiode having a special structure, which allows the high detection
efficiency required for tracking applications A first prototype was made o
f four arrays each containing 64 x 64 pixels, with a readout pitch of 20 mu
m in both directions. An architecture allowing serial readout of the analog
ue information from each pixel has been implemented. To evaluate the tracki
ng performance of such a device, series of tests have been performed using
a high-energy particle beam. A detailed analysis of the beam test data pres
ented in this work demonstrate close to 100% minimum ionising particle dete
ction efficiency and a good enough signal-to-noise ratio of more than 30. (
C) 2001 Elsevier Science B,V, All rights reserved.