Fabrication, characterization and simulation of channel stop for n in p-substrate silicon pixel detectors

• Published in: Journal of instrumentation Vol. 9; no. 7; p. C07013
• Main Authors: Thungström, G, Esebamen, O, Krapohl, D, Fröjdh, C, Nilsson, H -E, Petersson, S, Brenner, R
• Format: Journal Article
• Language: English
• Published: 01.07.2014
• Subjects: Electronic detector readout concepts (solid-state); Radiation-hard detectors; Solid state detectors
• ISSN: 1748-0221; 1748-0221
• DOI: 10.1088/1748-0221/9/07/C07013

Silicon detectors made on p-substrates are expected to have a better radiation hardness as compared todetectors made on n-substrates. However, the fixed positive oxide charges induce an inversion layer ofelectrons in the substrate, which connects the pixels. The common means of solving this problem isby using a p-spray, individual p-stops or a combination of the two. Here, we investigate the use offield plates to suppress the fixed positive charges and to prevent the formation of an inversion layer.The fabricated detector shows a high breakdown voltage and low interpixel leakage current for astructure using biased field plates with a width of 20 μm. By using a spice model for simulation of thepreamplifier, a cross talk of about 1.6 % is achieved with this detector structure. The cross talk iscaused by capacitive and resistive coupling between the pixels