A cubic isotropic X-ray dose detector diode fabricated by DRIE of SOI substrates*

作者：Norlin Peter^*; Oberg Olof; Junique Stephane; Kaplan Wlodek; Andersson Jan Y; Nilsson Gorgen

来源：Sensors and Actuators A: Physical , 2014, 213: 116-121.

DOI：10.1016/j.sna.2014.04.014

• X-ray detector diode
• Isotropic response
• Angular independence
• Silicon
• Cube
• Dosimetry

A novel X-ray detector diode, optimized for angular independent (isotropic) dose response, is presented. The diode is designed as a silicon cube with p-n junctions on all six sides, which creates a device that is close to being symmetrical in 3D. The cube edge is 300 mu m or 410 mu m. Its manufacturing process is based on micromachining, featuring deep reactive ion etching (DRIE) of silicon-on-insulator (SOI) substrates, doping of vertical walls from gas phase dopants and re-fill of etched trenches with polysilicon.
The variation in detector response to 6 MV X-rays, in a +/- 30 degrees beam angle range, was at best +/- 0.5% for a cubic diode compared to +/- 3.3% for conventional diodes, which indicates improvement by a factor 7.

• 出版日期2014-7-1