G.A. Beck

Construction and performance of the ATLAS silicon microstrip barrel modules

Abstract The ATLAS Semiconductor Tracker (SCT) consists of four barrel cylinders and 18 end-cap disks. This paper describes the SCT modules of the barrel region, of which more than 2000 are about to be constructed. The module design is fixed. Its design concept is given together with the electrical, thermal and mechanical specifications. The pre-series production of the barrel modules is underway using mass-production procedures and jigs. The pre-series modules have given satisfactory performances on noise, noise occupancy, electrical as well as mechanical and thermal properties. In addition, irradiated modules were demonstrated to work successfully. Also first results from a 10-module system test are given.

Radiation-tolerant breakdown protection of silicon detectors using multiple floating guard rings

Abstract Multiple floating guard-ring designs have been optimised for high-voltage operation of silicon detectors, and processed on both single- and double-sided devices. Results are presented on their performance before and after being subjected to both ionising and non-ionising irradiation.

Junction depth dependence of breakdown in silicon detector diodes

Abstract The high voltage capability of detector diodes fabricated in the planar process is limited by the high field generated at the edge of the junction. We have fabricated diodes with increased junction depth with respect to our standard process and find a significantly higher breakdown voltage, in reasonable agreement with previous studies of junction breakdown.

Temperature dependence of reverse annealing in bulk damaged silicon

A recent proposal [1] has suggested a model for the operation of silicon detectors which should give rise to the suppression of reverse annealing after neutron irradiation. The results of an experiment to investigate that model, in which the silicon is cooled during irradiations and annealed at high temperature between irradiations, are presented.

The breakdown voltage of unguarded and field plate guarded silicon detector diodes

Abstract We have investigated the breakdown of 300 μm thick detector diodes by simulation and measurement. Finite element analysis reproduces the results of commonly used models in the case of conventional diodes, but demonstrates that they are inapplicable to diodes with the low bulk doping typical of detectors. The strong dependence of breakdown voltage on the magnitude of the oxide charge is quantified for unguarded diodes and for diodes with a simple field plate structure.