Development of silicon pad and strip detectors in high energy physics

Abstract

The unique properties of semiconductors makes them suitable for precise measurement of particle’s tracks and if placed in a magnetic field, high accuracy momentum measurements are possible. Silicon, with low band gap (1.12 eV) and electron-hole pair creation energy (3.62 eV) are very efficient to create a large number of charge carriers due to ionizing particle. High density (2.33 g/cm3) leads to large energy loss in detector bulk by ionizing particles, which gives access to production of thin detector with fairly large signal. With high electronmobility (μe =1450cm2/Vs) and hole mobility (μh = 450 cm2/Vs) silicon detector provides very fast signal. The Planner technology is widely used for fabrication of semiconductor detectors. The main steps of fabrication of semiconductor detectors are passivation, patterning, doping to form P+ and N+ regions, contacts. In this paper, the fabrication of Silicon Pad Detector at IIT Bombay has been described.