INTEGRATED RADIATION PIXEL DETECTOR WITH PIN DIODE ARRAY

A particle detector has pixels arranged in rows and columns in a array-like formation and readout circuits for determining which of these pixels were hit by an ionizing particle. The pixels each including a PIN diode and charge transferring circuitry are integrated on a common silicon substrate with the readout circuits. Column buses and row buses are provided, associated with the pixels on the same column or row. A priority encoder gives the address of the highest numbered input that is asserted. Electric charge collected by a hit pixel is stored momentarily on a collection electrode and affects the current flow from the column bus to the row bus associated with the pixel. The column buses are sequentially activated and variations in the row currents are examined in parallel. To efficiently and accurately collect charge from the substrate, wells are used to which also contain the transferring circuitry and readout circuits. The wells also provide electrostatic shielding and prevent drain to source transistor punchthrough. The PIN-diodes and the collection electrodes are arranged close to but not connected to the well.