The New Silicon Strip Detectors for the CMS Tracker Upgrade

Autoren: Marko Dragicevic
Gruppe: CMS Tracker
Kategorie: PhD-Thesis

The first introductory part of the thesis describes the concept of the CMS experiment. The tasks of the various detector systems and their technical implementations in CMS are explained.

To facilitate the understanding of the basic principles of silicon strip sensors, the subsequent chapter discusses the fundamentals in semiconductor technology, with particular emphasis on silicon. The necessary process steps to manufacture strip sensors in a so-called planar process are described in detail. Furthermore, the effects of irradiation on silicon strip sensors are discussed.

To conclude the introductory part of the thesis, the design of the silicon strip sensors of the CMS Tracker are described in detail. The choice of the substrate material and the complex geometry of the sensors are reviewed and the quality assurance procedures for the production of the sensors are presented. Furthermore the design of the detector modules are described.

The main part of this thesis starts with a discussion on the demands on the tracker caused by the increase in luminosity which is proposed as an upgrade to the LHC accelerator (sLHC). This chapter motivates the work I have conducted and clarifies why the solutions proposed by myself are important contributions to the upgrade of the CMS tracker.

The following chapters present the concepts that are necessary to operate the silicon strip sensors at sLHC luminosities and additional improvements to the construction and quality assurance of the sensors and the detector modules. The most important concepts and works presented in chapters 7 to 9 are:

- Development of a software framework to enable the flexible and quick design of test structures and sensors.

- Selecting a suitable sensor material which is sufficiently radiation hard.

- Design, implementation and production of a standard set of test structures to enable the quality assurance of such sensors and any future developments.

- Electrical characterisation of the test structures and analysis of the measurements.

- Design, implementation and production of sensors with integrated routing of signals from the sensor strip to the readout electronics.

- Electrical characterisation of the sensors and analysis of the measurements.

- Operational tests of the integrated sensors in a test beam experiment.

- Analysis of the data recorded during the test beam experiment.

All the sensors and a part of the test structures were solely designed by me and implemented using tools which were created by myself as well. The manufacturing process for the sensors and test structures was implemented in close collaboration with the manufacturer. Furthermore, the necessary analysis of the data was supervised by me and the results are presented in this thesis for the first time.