Monolithic Active Pixel Sensor Technology Research Articles

Simulation and first characterization of MAPS test structures with gain for timing applications

Thanks to their advantages in terms of easiness of manufacturing and reduced production costs, Monolithic Active Pixel Sensors (MAPS) represent an appealing solution for radiation imaging applications, which require to cover large areas with pixelated detectors. In the next upgrade of the ALICE detector, that will have to deal with the higher event rate resulting from the planned increase in the LHC luminosity, it is foreseen to include two additional sensor layers to perform Time of Flight (ToF) measurements. Trying to reach the challenging timing resolution required by the ALICE ToF layers, an internal gain layer has been included in the test structures of the third engineering run of the ARCADIA project to improve the timing performance of this MAPS technology. In the paper we will present an overview of the main results obtained from the electrical and the dynamic characterization of the fabricated devices, which have been compared with the behavior expected from the preliminary TCAD simulations carried out in the design phase. The experimental results confirmed the feasibility of embedding a gain layer in the ARCADIA 110 nm CMOS technology to develop monolithic LGADs.

Advanced silicon tracking detector developments for the future Electron-Ion Collider

The proposed Electron-Ion Collider (EIC) will operate high-luminosity high-energy electron+proton and electron+nucleus collisions at the collision energies from 20 GeV to 141 GeV to solve several fundamental questions in the high energy and nuclear physics fields. Its instantaneous luminosity can reach 1033−34cm−2s−1 and the bunching crossing rate is around 10 ns. The EIC project has received CD1 approval from the US DOE in 2021 and moves toward the machine design and preparation for construction. To realize various particle measurements with high precision at the future EIC, a low material-budget and high-granularity silicon vertex and tracking detector with fine spatial and momentum resolutions and nearly 4π solid angle coverage is desired. The Monolithic Active Pixel Sensor (MAPS) and AC Coupled Low Gain Avalanche Diode (AC-LGAD) technologies stand out of several advanced technology options for the EIC silicon vertex and tracking detector subsystems. The MAPS technology has advanced features of low material budget, low power consumption, good radiation resistance and fine spatial resolution. The AC-LGAD technology can achieve fast timing resolution. Latest studies and progress of the EIC silicon vertex and tracking detector conceptual design, performance validations in simulation and ongoing MAPS and AC-LGAD R&D will be shown. Schedule and plan of the EIC project detector development will be discussed as well.

Fully Depleted MAPS in 110-nm CMOS Process With 100–300-μm Active Substrate

This article presents a fully depleted monolithic active pixel sensor technology compatible with a standard deep submicrometer 110-nm CMOS process. Passive test pixels structures, produced in various flavors, have proved the feasibility of 100- and 300- $\mu \text{m}$ -thick active substrates. Active pixel sensors with monolithically integrated analog and digital electronics, consisting of a 24 $\times $ 24 array of pixels with 50- $\mu \text{m}$ pitch, have been shown to be fully functional when operating in the full depletion mode. Characterization results obtained with a proton microbeam and a 55Fe radiation source are presented and discussed.

Characterisation of a monolithic active pixel sensor for electron detection in the energy range 10–20 keV

As part of a feasibility study into the use of novel electron detectors for X-ray photoelectron emission microscopes (XPEEM), we have characterised the imaging performance of a back-illuminated monolithic active pixel sensor (MAPS) operating under both integrating and counting modes for electrons in the energy range 10–20 keV. For integrating mode, we present the detective quantum efficiency (DQE), which shows marked improvements over conventional indirect detectors based on microchannel plates. We also present the modulation transfer function (MTF) and noise power spectrum (NPS), again demonstrating significantly improved performance. For counting mode, we present the quantum efficiency (QE) as a function of incident electron energy. We have evaluated the charge collection efficiency (CCE) and we thereby demonstrate the presence of a ~200 nm thick dead layer that is linked with reduced CCE at low electron energies. Based on our findings, we believe that the MAPS technology is well matched to future XPEEM instruments using aberration correction.

Characterisation of HEPAPS4—A family of CMOS active pixel sensors for charged particle detection

Monolithic active pixel sensor technology is a relatively inexpensive and reliable alternative to that of CCDs. Potential scientific applications for these devices include charged particle detection, indirect X-rays and neutron imaging. This paper reports on the characterisation and timing parameters optimisation of three different sensor variants from the HEPAPS4 family. The sensors feature standard three nMOS design but differ in the implementation of the photosensitive element. They have an array of 1024 × 384 pixels of 15 × 15 μ m 2 and 20 μ m epi-layer. Photonic methods are used to measure conversion gain, linearity, signal to noise ratio, dynamic range, pixel to pixel uniformity, dark current and read noise.