Thin‐film silicon detectors for particle detection

Abstract

PACS 29.40 Wk, 81.05 Gc, 85.60 Bt, Integrated particle sensors have been developed using thin-film on ASIC technology. For this purpose, hydrogenated amorphous silicon diodes, in various configurations, have been optimized for particle detection. These devices were first deposited on glass substrates to optimize the material properties and the dark current of very thick diodes (with thickness up to 50 µm). Corresponding diodes were later directly deposited on CMOS readout chips. These integrated particle sensors have been characterized using light pulse illumination and beta particle irradiation from 63 Ni and 90 Sr sources. Direct detection of single lowand high-energy beta particles have been demonstrated. The application of this new integrated particle sensor concept for medical imaging is also discussed.

Review of amorphous silicon based particle detectors: the quest for single particle detection

“…Such a monolithic device facilitates the integration of the detector with the readout electronics, reduces the related noise and can almost eliminate dead areas between pixels. TFA sensors were successfully developed, aiming at the detection of singly charged particles (including MIPs) and X-rays [74,75,76,77]. Examples of TFA detectors are shown in Figure 8.…”

TFA pixel sensor technology for vertex detectors

“…The sensor consists of a 15 mm thick aSi:H film forming a n-i-p diode. The a-Si:H is deposited using the Very High Frequency Plasma Enhanced Chemical Vapour Deposition (VHF PCVD) process, which is crucial for achieving high deposition rates with minimal mechanical stress and low defect density [2]. The deposition is performed at a rate of 15.6 Å /s and a frequency of 70 MHz, using hydrogen dilution of Silane.…”

“…The a-Si:H characteristics were first studied on test devices, in which n-i-p diodes were evaporated on chromium-coated glass. These structures were characterised by measuring current versus voltage in the dark and under illumination, and transient charge collection efficiency [2].…”

Hydrogenated Amorphous Silicon Sensors Based on Thin Film on ASIC Technology

“…2). 21 structures with areas of 18638 µm 2 or 167747 µm 2 and with different shapes are integrated to study the leakage current of the a-Si:H sensor and the detector pixel segmentation. Each structure is connected to current mirror stages which provide a current gain of 10 2 to 10 5 .…”

“…We have investigated an alternative solid state detector technology based on the deposition of a hydrogenated amorphous silicon sensor directly on top of the readout integrated circuit. This technology, called Thin-Film on ASIC (TFA) ( [1], [2]), potentially offers radiation hard alternatives to silicon devices. The vertical integration of a thin film sensor on the ASIC eliminates the need for bump bonding and enables a level of integration comparable to monolithic pixels while having the advantages of the hybrid pixel approach.…”