A NEW MICROSTRIP DETECTOR WITH DOUBLE-SIDED READOUT

A Si μ-strip detector has been developed with 50 μm pitch strips on both p- and n-side, using the principle of capacitive coupling between p+ diode strips - respectively n+ strips and the metallization strips which connect to the front-end preamplifiers. The detector is biased on both sides via polysilicon resistors connecting each p+or n+ line to a common bias bus. To allow ohmic separation at the n-side, the accumulation layer of electrons has to be disrupted between the n+ strips. This has been achieved in three different ways: i) separate polysilicon lines on thick oxide between two adjacent n+ lines to break the conducting accumulation layer by externally induced field depletion or using the metal lines of the n+ strips ii) on thick oxide and iii) on thin oxide. Results on 20×20 mm2 test devices will be presented. © 1990 IEEE