Development of depleted monolithic active pixel sensors for high rate and high radiation experiments at HL-LHC

Depleted monolithic active pixel sensors (DMAPS) are developed to demonstrate their suitability for high energy particle physics experiments in high radiation and high hit-rate environments. In this thesis, characterization of DMAPS prototypes in the large fill factor design using highly resistive wafers has been performed. Three prototypes, including a large-scale and fully-monolithic prototype, were fabricated using 150 nm CMOS technology on highly resistive (>2 kΩcm) wafers. The results of the characterization indicate that the DMAPS has capabilities to fulfill the requirements for the outer layers of the ATLAS ITk Pixel Detector. DMAPS prototypes coupled with an additional readout chip are also tested for future applications

Breakdown Performance of Guard Ring Designs for Pixel Detectors in 150 nm150~\mathrm{nm} CMOS Technology

Silicon pixel sensors manufactured using commercial CMOS processes are promising instruments for high-energy particle physics experiments due to their high yield and proven radiation hardness. As one of the essential factors for the operation of detectors, the breakdown performance of pixel sensors constitutes the upper limit of the operating voltage. Six types of passive CMOS test structures were fabricated on high-resistivity wafers. Each of them features a combination of different inter-pixel designs and sets of floating guard rings, which differ from each other in the geometrical layout, implantation type, and overhang structure. A comparative study based on leakage current measurements in the sensor substrate of unirradiated samples was carried out to identify correlations between guard ring designs and breakdown voltages. TCAD simulations using the design parameters of the test structures were performed to discuss the observations and, together with the measurements, ultimately provide design features targeting higher breakdown voltages

Prototype Active Silicon Sensor in 150 nm HR-CMOS Technology for ATLAS Inner Detector Upgrade

The LHC Phase-II upgrade will lead to a significant increase in luminosity, which in turn will bring new challenges for the operation of inner tracking detectors. A possible solution is to use active silicon sensors, taking advantage of commercial CMOS technologies. Currently ATLAS R&D programme is qualifying a few commercial technologies in terms of suitability for this task. In this paper a prototype designed in one of them (LFoundry 150 nm process) will be discussed. The chip architecture will be described, including different pixel types incorporated into the design, followed by simulation and measurement results.Comment: 9 pages, 9 figures, TWEPP 2015 Conference, submitted to JINS

Charge collection and efficiency measurements of the TJ-Monopix2 DMAPS in 180 \,nm CMOS technology

Monolithic CMOS pixel detectors have emerged as competitive contenders in the field of high-energy particle physics detectors. By utilizing commercial processes they offer high-volume production of such detectors. A series of prototypes has been designed in a 180$\,$nm Tower process with depletion of the sensor material and a column-drain readout architecture. The latest iteration, TJ-Monopix2, features a large 2$\,$cm x 2$\,$cm matrix consisting of 512 x 512 pixels with 33.04$\,$um pitch. A small collection electrode design aims at low power consumption and low noise while the radiation tolerance for high-energy particle detector applications needs extra attention. With a goal to reach radiation tolerance to levels of $10^{15}\,1\,$MeV n$_\text{eq}\,$cm$^{-2}$ of NIEL damage a modification of the standard process has been implemented by adding a low-dosed n-type silicon implant across the pixel in order to allow for homogeneous depletion of the sensor volume. Recent lab measurements and beam tests were conducted for unirradiated modules to study electrical characteristics and hit detection efficiency.Comment: Conference proceedings for PIXEL2022 conference, submitted to Po

CMOS pixel sensors on high resistive substrate for high-rate, high-radiation environments

In Press, Corrected Proof — Note to usersInternational audienceA depleted CMOS active pixel sensor (DMAPS) has been developed on a substrate with high resistivity in a high voltage process. High radiation tolerance and high time resolution can be expected because of the charge collection by drift. A prototype of DMAPS was fabricated in a 150 nm process by LFoundry. Two variants of the pixel layout were tested, and the measured depletion depths of the variants are 166 μm and 80 μm. We report the results obtained with the prototype fabricated in this technology

Depleted fully monolithic active CMOS pixel sensors (DMAPS) in high resistivity 150 nm technology for LHC

International audienceDepleted monolithic CMOS 1 1 Complementary metal-oxide-semiconductor.  active pixel sensors (DMAPS) have been developed to demonstrate their suitability as pixel detectors in the outer layers of the ATLAS Inner Tracker (ITk) pixel detector in the High-Luminosity Large Hadron Collider (HL-LHC). Two prototypes have been fabricated using a 150 nm CMOS technology on high resistivity ( ≥  2 k Ω cm) wafers. The chip size of 10 mm  ×  10 mm is similar to that of the current FE-I3 ATLAS pixel detector readout chip. One of the prototypes is used for detailed characterization of the sensor and analog front end circuitry of the DMAPS. The other one is a fully monolithic DMAPS, including fast readout digital logics that handle the required hit rate. To yield a strong homogeneous electric field within the sensor volume, back-side process of the wafer was tested. The prototypes were irradiated with X-rays up to a total ionization dose (TID) of 50 Mrad(SiO 2 ) and with neutrons up to a 1 MeV neutron equivalent fluence of 10 15  n eq /cm 2 to test non-ionizing energy loss (NIEL) effects. The analog front end circuitry maintained its performance after TID irradiation, and the hit efficiency at < 10 −7 noise occupancy was as high as 98.9% after NIEL irradiation

Test results of irradiated CMOS pixel circuits in 150 nm CMOS technology for the ATLAS Inner Tracker Upgrade

International audienceA major upgrade for the ATLAS Inner Tracker at the Large Hadron Collider (LHC) is scheduled in 2026. Depleted CMOS pixel sensors on high resistivity substrates in LFoundry 150 nm technology are an interesting option for this upgrade. Recently two large demonstrators, one based on a hybrid concept called LF-CPIX and the other based on a fully monolithic concept called LF-Monopix have been produced. Both prototypes were characterized in the lab and after irradiation up to 160 MRad under CERN’s 24 GeV Proton Synchrotron beam. In this work, we will describe the behavior under radiation of the two prototypes

Development of depleted monolithic pixel sensors in 150 nm CMOS technology for the ATLAS Inner Tracker upgrade

International audienceThis work presents a depleted monolithic active pixel sensor (DMAPS) prototype manufactured in the LFoundry 150 nm CMOS process. The described device, named LF-Monopix, was designed as a proof of concept of a fully monolithic sensor capable of operating in the environment of outer layers of the ATLAS Inner Tracker upgrade for the High Luminosity Large Hadron Collider (HL-LHC). Implementing such a device in the detector module will result in a lower production cost and lower material budget compared to the presently used hybrid designs. In this paper the chip architecture will be described followed by the simulation and measurement results