CONCEPTS FOR SIMPLIFICATION OF STRIP DETECTOR DESIGN AND PRODUCTION

The original design of strip detectors has been rather straightforward and simple. The single-sided devices consisted of a large number of closely spaced diode strips and an ohmic contact extending over the whole wafer backside. Only two photolithographic steps for diode implantation and metallization - which even could be done with a single mask and its complement - were needed. With increasing sophistication and the introduction of ASICs for readout, more functions were included in the detectors. e.g. double-sided readout, capacitive coupling of the readout electronics and resistive biasing. This has resulted in considerable complication of the fabrication process using 11 or more photolithographic steps. Considerable simplification could be achieved by a new biasing scheme resulting for double-sided detectors in a reduction of photolithographic steps by a factor of two. In view of the proposed large scale applications in future high energy accelerators the question of possible further simplification is discussed. As ultimate reduction we propose a method for production of double-sided capacitively coupled strip detectors by using only one implantation and three photolithographic steps.