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The Avalanche drift diode—A backilluminated Silicon Photomultiplier
ARTICLE IN PRESS
Nuclear Instruments and Methods in Physics Research A 572 (2007) 454–455 www.elsevier.com/locate/nima
The Avalanche drift diode—A backilluminated Silicon Photomultiplier Jelena Ninkovic´a,b,, Robert Hartmannb,c, Peter Hollb,c, Gerhard Lutza,b, Christine Mercka,b, Razmik Mirzoyana, Hans-Gu¨nther Mosera,b, Adam-Nepomuk Ottea,b, Rainer Richtera,b, Heike Soltaub,c, Masahiro Teshimaa a
Max-Planck-Institute for Physics, Fo¨hringer Ring 6, D-80805 Munich, Germany MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, D-81739 Munich, Germany c PNSensor GmbH, Ro¨merstr. 28, D-80803 Munich, Germany
b
Available online 27 November 2006
Abstract Recently a new type of photodetector was introduced; the so-called Silicon PhotoMultiplier (SiPM). Its good characteristics make SiPM suitable for many applications. Yet, for low light level applications higher quantum efficiency is required. A new detector concept is presented that promises very high (close to 100%) quantum efficiency in a wide wavelength range. r 2006 Elsevier B.V. All rights reserved. PACS: 85.60.Gz; 95.55.Aq; 42.50.Ar Keywords: Single photon counting; High quantum efficiency; Backilluminated SiPM; Drift diode
1. Introduction High energy particle showers generated by cosmic radiation are to be reconstructed in experiments like MAGIC by observing Cherenkov light. The detectors used so far (photomultipliers) have low quantum efficiency especially in the interesting UV range ( 25%). In time resolved astronomy rapidly varying astronomical objects are observed by looking at the time dependence of their optical emission. For this the single photon efficiency, position and time resolution of photo sensors is of utmost importance. 2. The Avalanche Drift Diode (ADD) concept The ADD consists (like the existing SiPM [1]) of many small area avalanche diodes working in the limited Geiger mode. Each of these micro-cells provides a standard pulse when an avalanche is initiated in it. Corresponding author. MPI Semiconductor Laboratory, Otto-HahnRing 6, D-81739 Munich, Germany E-mail address: [email protected] (J. Ninkovic´).
0168-9002/$ - see front matter r 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.nima.2006.10.298
Addition of signals from an array of such cells, provides a measure for the number of photons detected within the macro-cell. The quantum efficiency of front illuminated SiPMs is limited by the small fill factor of the radiation entrance side. In the new concept radiation enters from the back of a fully depleted wafer and the photoelectrons are focused onto a small ‘‘point-like’’ avalanche region located on the front side (Fig. 1). A shallow and homogeneous diode on the fully depleted n-type wafer forms the radiation entrance window. The avalanche structure is created by the nþ -doped anode (A) and a buried p-type layer (deep-p) which is connected laterally through the innermost pþ -doped ring ðR0 Þ. The negatively biased drift rings R1 , R2 focus the photo-electrons towards the center avalanche region. Results from extended device simulations can be found in Refs. [2–4]. In our new photon detector concept the 100% fill factor of the radiation entrance window leads to higher quantum efficiency compared to the front illuminated SiPMs. In addition, deposition of antireflective coatings and optical filters can optimize the entrance window for a specific application [5,6]. Simulation of different UV enhanced antireflective coatings is shown in Fig. 2.
ARTICLE IN PRESS J. Ninkovic´ et al. / Nuclear Instruments and Methods in Physics Research A 572 (2007) 454–455
radiation entrance window
photon
p+ drift rings p
+
avalanche region
n-
455
wavelength range. Estimated properties from the performed simulations make this detector ideal for future imaging air Cherenkov telescopes [4]. Dedicated test structures are currently produced for the verification of the concept.
deep p+ drift path of ap eR2
R1
R0
A (n+) resistor
readout line
Fig. 1. Concept of the Avalanche Drift Diode.
Fig. 2. Simulated quantum efficiency for different antireflective coatings.
3. Conclusions Our new concept of the ADD structure promises high photon detection efficiency (480%) over the full optical
References [1] B. Dolgoshein, et al., Nucl. Instr. and Meth. A 504 (2003) 48. [2] G. Lutz, et al., IEEE Trans. Nucl. Sci. NS-52 (2005) 1156. [3] G. Lutz, et al., Proceedings of Beaune, 2005, Nucl. Instr. and Meth. A, submitted for publication. [4] N. Otte, et al., IEEE Trans. Nucl. Sci. NS-53 (2) (2006) 636. [5] R. Hartmann, et al., Nucl. Instr. and Meth. A 439 (2000) 216. [6] R. Hartmann, et al., Proc. SPIE 5903 (2005) N1.
Nuclear Instruments and Methods in Physics Research A 572 (2007) 454–455 www.elsevier.com/locate/nima
The Avalanche drift diode—A backilluminated Silicon Photomultiplier Jelena Ninkovic´a,b,, Robert Hartmannb,c, Peter Hollb,c, Gerhard Lutza,b, Christine Mercka,b, Razmik Mirzoyana, Hans-Gu¨nther Mosera,b, Adam-Nepomuk Ottea,b, Rainer Richtera,b, Heike Soltaub,c, Masahiro Teshimaa a
Max-Planck-Institute for Physics, Fo¨hringer Ring 6, D-80805 Munich, Germany MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, D-81739 Munich, Germany c PNSensor GmbH, Ro¨merstr. 28, D-80803 Munich, Germany
b
Available online 27 November 2006
Abstract Recently a new type of photodetector was introduced; the so-called Silicon PhotoMultiplier (SiPM). Its good characteristics make SiPM suitable for many applications. Yet, for low light level applications higher quantum efficiency is required. A new detector concept is presented that promises very high (close to 100%) quantum efficiency in a wide wavelength range. r 2006 Elsevier B.V. All rights reserved. PACS: 85.60.Gz; 95.55.Aq; 42.50.Ar Keywords: Single photon counting; High quantum efficiency; Backilluminated SiPM; Drift diode
1. Introduction High energy particle showers generated by cosmic radiation are to be reconstructed in experiments like MAGIC by observing Cherenkov light. The detectors used so far (photomultipliers) have low quantum efficiency especially in the interesting UV range ( 25%). In time resolved astronomy rapidly varying astronomical objects are observed by looking at the time dependence of their optical emission. For this the single photon efficiency, position and time resolution of photo sensors is of utmost importance. 2. The Avalanche Drift Diode (ADD) concept The ADD consists (like the existing SiPM [1]) of many small area avalanche diodes working in the limited Geiger mode. Each of these micro-cells provides a standard pulse when an avalanche is initiated in it. Corresponding author. MPI Semiconductor Laboratory, Otto-HahnRing 6, D-81739 Munich, Germany E-mail address: [email protected] (J. Ninkovic´).
0168-9002/$ - see front matter r 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.nima.2006.10.298
Addition of signals from an array of such cells, provides a measure for the number of photons detected within the macro-cell. The quantum efficiency of front illuminated SiPMs is limited by the small fill factor of the radiation entrance side. In the new concept radiation enters from the back of a fully depleted wafer and the photoelectrons are focused onto a small ‘‘point-like’’ avalanche region located on the front side (Fig. 1). A shallow and homogeneous diode on the fully depleted n-type wafer forms the radiation entrance window. The avalanche structure is created by the nþ -doped anode (A) and a buried p-type layer (deep-p) which is connected laterally through the innermost pþ -doped ring ðR0 Þ. The negatively biased drift rings R1 , R2 focus the photo-electrons towards the center avalanche region. Results from extended device simulations can be found in Refs. [2–4]. In our new photon detector concept the 100% fill factor of the radiation entrance window leads to higher quantum efficiency compared to the front illuminated SiPMs. In addition, deposition of antireflective coatings and optical filters can optimize the entrance window for a specific application [5,6]. Simulation of different UV enhanced antireflective coatings is shown in Fig. 2.
ARTICLE IN PRESS J. Ninkovic´ et al. / Nuclear Instruments and Methods in Physics Research A 572 (2007) 454–455
radiation entrance window
photon
p+ drift rings p
+
avalanche region
n-
455
wavelength range. Estimated properties from the performed simulations make this detector ideal for future imaging air Cherenkov telescopes [4]. Dedicated test structures are currently produced for the verification of the concept.
deep p+ drift path of ap eR2
R1
R0
A (n+) resistor
readout line
Fig. 1. Concept of the Avalanche Drift Diode.
Fig. 2. Simulated quantum efficiency for different antireflective coatings.
3. Conclusions Our new concept of the ADD structure promises high photon detection efficiency (480%) over the full optical
References [1] B. Dolgoshein, et al., Nucl. Instr. and Meth. A 504 (2003) 48. [2] G. Lutz, et al., IEEE Trans. Nucl. Sci. NS-52 (2005) 1156. [3] G. Lutz, et al., Proceedings of Beaune, 2005, Nucl. Instr. and Meth. A, submitted for publication. [4] N. Otte, et al., IEEE Trans. Nucl. Sci. NS-53 (2) (2006) 636. [5] R. Hartmann, et al., Nucl. Instr. and Meth. A 439 (2000) 216. [6] R. Hartmann, et al., Proc. SPIE 5903 (2005) N1.