Feb 18 – 22, 2019
Vienna University of Technology
Europe/Vienna timezone

Processing of AC-coupled n-in-p pixel detectors on MCz silicon using atomic layer deposition (ALD) grown aluminium oxide

Not scheduled
Vienna University of Technology

Vienna University of Technology

Gusshausstraße 27-29, 1040 Wien
Board: 87
Poster Semiconductor Detectors Poster Session B


Jennifer Ott (Helsinki Institute of Physics (FI))


We report on the fabrication of capacitively-coupled (AC) n+-in-p pixel detectors on magnetic Czochralski silicon substrates. In our devices, we employ a layer of aluminium oxide (Al$_2$O$_3$) grown by atomic layer deposition (ALD) as dielectric and field insulator, instead of the commonly used SiO$_2$. As shown in earlier research, Al$_2$O$_3$ thin films exhibit high negative oxide charge, and can thus serve as a substitute for p-stop/p-spray insulation implants between pixels. In addition, they provide far higher capacitance densities than SiO$_2$ due to their high dielectric constant, permitting more efficient capacitive coupling of pixels. Furthermore, metallic titanium nitride (TiN) bias resistors are presented as an alternative to punch-through or poly-Si resistors.

Devices obtained by the abovementioned process are characterized by CV, IV, and TCT measurements, and by 2 MeV proton microprobe. Results show the expected high negative charge of the Al$_2$O$_3$ dielectric, uniform charge collection efficiency over large areas of pixels, and acceptable leakage current densities.

Primary authors

Jennifer Ott (Helsinki Institute of Physics (FI)) Akiko Gädda (Helsiki Institute of Physics) Maria Golovleva (Helsinki Institute of Physics (FI)) Tiina Sirea Naaranoja (Helsinki Institute of Physics (FI)) Laura Martikainen (Helsinki Institute of Physics (FI)) Jens Erik Brucken (Helsinki Institute of Physics (FI)) Vladyslav Litichevskyi (Helsinki Institute of Physics (FI)) Matti Kalliokoski (CERN (CH)) Dr Aneliya Karadzhinova (Rudjer Boskovic Institute (HR)) Panja Luukka (Helsinki Institute of Physics (FI)) Jaakko Härkönen (Rudjer Boskovic Institute (HR))

Presentation materials