Performance of a pMOS pixel to be used in radiation detectors

A pMOS pixel to be used in a striplike two-dimensional readout single-sided detector has been developed and tested. It is originally proposed for upgrades of the vertex detector of the BELLE experiment at the KEK B-factory: in order to overcome low signal-to-noise ratio of the double-sided silicon strip detector to be used presently. This device gathers the pMOS transistor amplification with the typical silicon pin diode used in particle detection. In a 100/spl times/100 /spl mu/m/sup 2/ n-type collecting electrode a double drain pMOS transistor is implanted, providing (1) a two-dimensional readout and (2) direct signal amplification. With the subdivision in pixels, which lowers the detector capacitance, a high signal-to-noise ratio is expected. The two-dimensional readout and the low noise advantages of this structure can be used for detection of any electromagnetic radiation as well as high energy charged particles. Nuclear physics, space and astrophysics instrumentation, are also potential field of application for the pMOS pixel. We briefly review here the principle of the structure and describe the test of the prototypes in detail.