A NEW INTEGRATED PIXEL DETECTOR FOR HIGH-ENERGY PHYSICS

We have fabricated integrated pixel devices which have the high-resistivity, signal-charge collecting volume and the read-out circuitry in a single piece of silicon. The integration of both detecting elements and circuitry is carried out by building the circuitry on top of the detecting elements [1] maximizing spatial resolution. Loss of signal charge into the circuitry where it would be lost for readout is avoided. Both circuitry and detecting elements are fully functional. Tests with infrared illumination and gamma irradiation have been carried out on wafer before dicing and packaging[1, 2]. Here we present noise measurements illustrating the excellent signal to single-channel noise performance of this device of about 150 to 1 for a minimum ionizing particle, which is an order of magnitude better than silicon strip detectors currently used. We also made a setup for packaged devices, and gamma irradiation measurement results obtained with this setup illustrate the high signal to noise performance and good uniformity in sensivity over the different pixels.