Evaluating the influence of MCM-D post-processing on silicon microstrip sensors

Abstract

Silicon micro-strip modules are traditionally built as a composite object of sensors, front-end ASICs, electronics hybrid, pitch adapters and passive components. This paper reports on a novel approach to use Multi-chip Module-Deposited (MCM-D) technology to build the electronics hybrid and pitch adapter directly on the silicon sensor, by post-processing the sensor wafers. A first prototype was made to evaluate the influence of the post-processing on the sensors in terms of the electrical performance, mechanical stability and the radiation hardness. The processing was done on a wafer with miniature strip sensors and featured one dielectric layer, one metal layer and one passivation layer. This paper summarises the results from this prototype run. It reports on the sensor leakage current, strip capacitance, inter-strip resistance and charge collection efficiency. These measurements are done on non-irradiated devices and devices subjected to proton irradiation. Furthermore it reports on the mechanical integrity of the post-processed assembly.