Radiation detection performance of very high gain avalanche photodiodes (original) (raw)

High resolution, low energy avalanche photodiode X-ray detectors

IEEE Transactions on Nuclear Science, 1991

Silicon avalanche photodiodes have been fabricated and their performance as X-ray detectors has been measured. Photon sensitivity and energy resolution was measured as a function of size and operating parameters. Noise thresholds as low as 212eV were obtained at room temperature and backscatter X-ray fluorescence data was obtained for aluminum and Other light elements.

Silicon avalanche photodiodes evaluation for low-energy single-photon scintillation readout

The aim of this work was to evaluate the suitability of Si avalanche photodiodes for low-energy scintillation readout in single-photon modality. The energy of interest for low-energy nuclear medicine applications is in the range from 100 keV to 200 keV. We studied experimental assemblies based on a small parallelepiped CsI(Tl) scintillation crystal coupled to different single-photosensors. A model describing the scintillation light distribution emerging from the crystal was used to choose the photodiode models and to foresee the assembly responses. Some Hamamatsu S8664-series photodiodes were selected for this preliminary study, with the aim of future applications involving S8550 arrays made by the same manufacturer. Pulse height and energy resolution have been mainly studied.

Recent progress of avalanche photodiodes in high-resolution X-rays and -rays detection

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2005

We have studied the performance of large area avalanche photodiodes (APDs) recently developed by Hamamatsu Photonics K.K, in high-resolution X-rays and γrays detections. We show that reach-through APD can be an excellent soft X-ray detector operating at room temperature or moderately cooled environment. We obtain the best energy resolution ever achieved with APDs, 6.4 % for 5.9 keV X-rays, and obtain the energy threshold as low as 0.5 keV measured at −20 • C. Thanks to its fast timing response, signal carriers in the APD device are collected within a short time interval of 1.9 nsec (FWHM). This type of APDs can therefore be used as a low-energy, high-counting particle monitor onboard the forthcoming Picosatellite Cute1.7. As a scintillation photon detector, reverse-type APDs have a good advantage of reducing the dark noise significantly. The best FWHM energy resolutions of 9.4±0.3% and 4.9±0.2% were obtained for 59.5 keV and 662 keV γ-rays, respectively, as measured with a CsI(Tl) crystal. Combination of APDs with various other scintillators (BGO, GSO, and YAP) also showed better results than that obtained with a photomultiplier tube (PMT). These results suggest that APD could be a promising device for replacing traditional PMT usage in some applications. In particular 2-dim APD array, which we present in this paper, will be a promising device for a wide-band X-ray and γ-ray imaging detector in future space research and nuclear medicine.

Performance of a novel planar-processed avalanche photodiode for light and x-ray detection

Optical Engineering, 2003

We have performed a detailed investigation of the light and x-ray response of a newly developed planar avalanche photodiode (APD) of the deep diffused type. This type of photodetector design has the low noise characteristics obtained from the deep diffusion process, but it is built using only standard planar technology. We measured an excess noise factor of 1.8 at a gain of 6, which is similar to other commercial APDs. With this type of structure, the expected gain is ~ 500 at 1600 V. We have not achieved this gain because there is early breakdown at the surface. Future designs will incorporate improvements in the structure to avoid surface breakdown. In spite of this, the low noise obtained at a gain of 6, indicates that this structure, reaching full breakdown, has potential to work with very low noise. At this gain, it is found that the dominant contribution to the broadening of the energy resolution comes from preamplifier voltage noise. The measured capacitance was 20 pF, and the rise time 11 ns at 1300 V. The dependence of the gain with the density of generated carriers has also been investigated. When the gain is measured with α

Characterization of novel active area silicon avalanche photodiodes operating in the geiger mode

Journal of Modern Optics, 2004

We present a method for characterizing avalanche photodiode (APD) photon-counting detector efficiency as a function of active area. Various shallow-junction silicon APDs having a novel active area were manufactured and tested. We show that cylindrical and checkquerboard-shaped active areas have dark counts two orders of magnitude lower than standard circular devices with an equivalent active area. A parallel implementation of small active areas creates gettering sites for defects to migrate to, which is believed to create relatively defect-free active areas as the perimeter-to-area ratio is increased. However, a compromise between a large perimeter-to-area ratio and a structure useful for practical applications must be considered to optimize the detector.

Simulation of signal generation for silicon avalanche photodiodes (APDs)

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2000

Silicon Avalanche Photodiodes (APDs) are currently proposed as readout devices for the electromagnetic calorimeters to be used in proposed new detectors. In the present paper the photon detection mechanism of APDs is investigated and we discuss possible APD structures that would be suitable for particle physics experiments. Calculations were made with a Single-Particle Monte Carlo simulation technique, written in Fortran.

CMOS-based avalanche photodiodes for direct particle detection

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2007

Active Pixel Sensors (APSs) in CMOS (complementary metal-oxide-semiconductor) technology are augmenting Charge-Coupled Devices (CCDs) as imaging devices and cameras in some demanding optical imaging applications. Radiation Monitoring Devices is investigating the APS concept for nuclear detection applications and has successfully migrated avalanche-photodiode pixel fabrication to a CMOS environment, creating pixel detectors that can be operated with internal gain as proportional detectors. Amplification of the signal within the diode allows identification of events previously hidden within the readout noise of the electronics. Such devices can be used to read out a scintillation crystal, as in SPECT or PET, and as direct-conversion particle detectors. The charge produced by an ionizing particle in the epitaxial layer is collected by an electric field within the diode in each pixel. The monolithic integration of the readout circuitry with the pixel sensors represents an improved design compared to the current hybrid-detector technology that requires wire or bump bonding. In this work, we investigate designs for CMOS avalanche photodiode (APD) detector elements and compare these to typical values for large area devices. We characterize the achievable detector gain and the gain uniformity over the active area. The excess noise in two different pixel structures is compared. The CMOS APD performance is demonstrated by measuring the energy spectra of x-rays from 55 Fe.

A novel silicon Geiger-mode avalanche photodiode

… Meeting, 2002. IEDM' …, 2002

Dark count non-linearity in CMOS compatible, single photon counting, Geiger-mode avalanche photodiodes (GM-APD) has been investigated. A novel structure was designed, fabricated, and characterized to allow dark count optimization. Dark count levels for the proposed structure are shown to scale linearly with area.