Abstract

Proto-type Silicon Drift Detectors SDDs have been realized through a pilot stage fabrication run at the Micro-fabrication facility at Indian Institute of Technology - Bombay IIT-B Taking precedence from the fabrication run at IIT-B commercial grade SDDs with on-chip low noise JFETs are being developed for low energy X-ray spectroscopy and position sensing applications using silicon bipolar technology available with Bharat Electronics Ltd BEL Bangalore This paper presents a detailed illustrative view on the design fabrication and characterization of the SDDs in-built JFETs fabricated at BEL Traditionally detectors are fabricated over high resistivity silicon substrates whereas JFETs are fabricated over low-resistivity silicon To design a process for fabrication of both SDD and JFET over high resistivity silicon posed a sufficient technological challenge Simulations in Technology Computer Aided Design TCAD proved helpful in arriving at optimum process parameter values for fabrication of SDDs and on-chip JFETs over the same high resistivity silicon substrate SDDs low noise JFETs fabricated at BEL were characterized to extract dc I-V performance parameters like total leakage current at anode transconductance etc These results formed precursors to fine-tuning the process for the next run aimed at achieving an even lower leakage current level