EFFECTS OF DIELECTRICS ON THE CHARACTERISTICS OF LARGE-AREA SILICON MICROSTRIP SENSORS

An 8 x 4 cm(2) single-sided silicon microstrip sensor with coupling ca pacitors and polysilicon bias resistors has been fabricated with plana r technology. The oxide-nitride-oxide (ONO) films have been chosen to replace the usual SiO2 layer as the dielectric of the coupling capacit or. In conjunction with a reordering of the process sequence for layer formations, the proposed process could be used to fabricate sensors w ith self-moisture protection and free from the effect of pinholes. Fro m the measurement results of special p-n junction test structures, we found that their leakage current was dominated by that of the sidewall one. Stress measurement and Sirt1-etch analysis revealed that the sid ewall leakage current was increased bq the dielectric stress and impla ntation damage. A boron solid-source predeposition process was employe d to reduce this leakage current. From the results of electrical measu rement and beam test on sensors, it was shown that the proposed proces s uas able to produce sensors having very good performance.