{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T02:00:30Z","timestamp":1775700030167,"version":"3.50.1"},"reference-count":24,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2021,5,31]],"date-time":"2021-05-31T00:00:00Z","timestamp":1622419200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Fully Depleted Monolithic Active Pixel Sensors (FD-MAPS) represent an appealing alternative to hybrid detectors for radiation imaging applications. We have recently demonstrated the feasibility of FD-MAPS based on a commercial 110 nm CMOS technology, adapted using high-resistivity substrates and backside post-processing. A p\/n junction diode, fabricated on the detector backside using low-temperature processing steps after the completion of the front-side Back End of Line (BEOL), is reverse-biased to achieve the full depletion of the substrate and thus fast charge collection by drift. Test diodes including termination structures with different numbers of floating guard rings and different pitches were fabricated together with other Process Control Monitor structures. In this paper, we present the design of the backside diodes, together with results from the electrical characterization of the test devices, aiming to improve understanding of the strengths and limitations of the proposed approach. Characterization results obtained on several wafers demonstrate the effectiveness of the termination rings in increasing the breakdown voltage of the backside diodes and in coping with the variability of the passivation layer characteristics. A breakdown voltage exceeding 400 V in the worst case was demonstrated in devices with 30 guard rings with 6 \u03bcm pitch, thus enabling the full depletion of high-resistivity substrates with a thickness larger than or equal to 300 \u03bcm. Additionally, we show the first direct comparison for this technology of measured pixel characteristics with 3D TCAD simulations, proving a good agreement in the extracted operating voltages.<\/jats:p>","DOI":"10.3390\/s21113809","type":"journal-article","created":{"date-parts":[[2021,5,31]],"date-time":"2021-05-31T21:42:06Z","timestamp":1622497326000},"page":"3809","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Design and Characterization of Backside Termination Structures for Thick Fully-Depleted MAPS"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0236-6834","authenticated-orcid":false,"given":"Thomas","family":"Corradino","sequence":"first","affiliation":[{"name":"Dipartimento di Ingegneria Industriale, Universit\u00e0 degli Studi di Trento, 38123 Trento, Italy"},{"name":"Trento Institute for Fundamental Physics and Applications\u2013Istituto Nazionale di Fisica Nucleare (TIFPA-INFN), 38123 Trento, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5516-9282","authenticated-orcid":false,"given":"Gian-Franco","family":"Dalla Betta","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria Industriale, Universit\u00e0 degli Studi di Trento, 38123 Trento, Italy"},{"name":"Trento Institute for Fundamental Physics and Applications\u2013Istituto Nazionale di Fisica Nucleare (TIFPA-INFN), 38123 Trento, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5986-3842","authenticated-orcid":false,"given":"Lorenzo","family":"De Cilladi","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica, Universit\u00e0 degli Studi di Torino, 10125 Torino, Italy"},{"name":"Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, 10125 Torino, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2008-8404","authenticated-orcid":false,"given":"Coralie","family":"Neub\u00fcser","sequence":"additional","affiliation":[{"name":"Trento Institute for Fundamental Physics and Applications\u2013Istituto Nazionale di Fisica Nucleare (TIFPA-INFN), 38123 Trento, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3954-7308","authenticated-orcid":false,"given":"Lucio","family":"Pancheri","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria Industriale, Universit\u00e0 degli Studi di Trento, 38123 Trento, Italy"},{"name":"Trento Institute for Fundamental Physics and Applications\u2013Istituto Nazionale di Fisica Nucleare (TIFPA-INFN), 38123 Trento, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.nima.2018.06.034","article-title":"Monolithic CMOS sensors for high energy physics","volume":"924","author":"Snoeys","year":"2019","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1016\/S0168-9002(02)02043-0","article-title":"Monolithic active pixel sensors (MAPS) in a VLSI CMOS technology","volume":"501","author":"Turchetta","year":"2003","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/j.nima.2005.11.241","article-title":"CMOS Monolithic Active Pixel Sensors (MAPS): New \u2019eyes\u2019 for science","volume":"560","author":"Turchetta","year":"2006","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1016\/j.nima.2018.07.003","article-title":"Pixel detectors... where do we stand?","volume":"924","author":"Wermes","year":"2019","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"434","DOI":"10.1016\/j.nima.2015.09.057","article-title":"ALPIDE, the Monolithic Active Pixel Sensor for the ALICE ITS upgrade","volume":"824","author":"Mager","year":"2016","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1016\/j.nima.2017.07.046","article-title":"A process modification for CMOS monolithic active pixel sensors for enhanced depletion, timing performance and radiation tolerance","volume":"871","author":"Snoeys","year":"2017","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Schioppa, E.J., Bates, R., Buttar, C., Dalla, M., Van Hoorne, J.W., Kugathasan, T., Maneuski, D., Tobon, C.A.M., Musa, L., and Parnegger, H. (2017, January 2\u20136). Radiation Hardness Studies on a Novel CMOS Process for Depleted Monolithic Active Pixel Sensors. Proceedings of the 2017 17th European Conference on Radiation and Its Effects on Components and Systems (RADECS), Geneva, Switzerland.","DOI":"10.1109\/RADECS.2017.8696182"},{"key":"ref_8","first-page":"2732","article-title":"SOI Monolithic Active Pixel Sensors for Radiation Detection Applications: A Review","volume":"15","author":"Lan","year":"2015","journal-title":"IEEE Sens. J."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1016\/j.nima.2016.03.095","article-title":"Characteristics of non-irradiated and irradiated double SOI integration type pixel sensor","volume":"831","author":"Asano","year":"2016","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"876","DOI":"10.1016\/j.nima.2007.07.115","article-title":"A novel monolithic pixelated particle detector implemented in high-voltage CMOS technology","volume":"582","author":"Peric","year":"2007","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"C01039","DOI":"10.1088\/1748-0221\/12\/01\/C01039","article-title":"Development of a depleted monolithic CMOS sensor in a 150 nm CMOS technology for the ATLAS inner tracker upgrade","volume":"12","author":"Wang","year":"2017","journal-title":"J. Instrum."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Stefanov, K.D., Clarke, A.S., Ivory, J., and Holland, A.D. (June, January 30). Fully Depleted, Monolithic Pinned Photodiode CMOS Image Sensor Using Reverse Substrate Bias. Proceedings of the 2017 International Image Sensor Workshop, Hiroshima, Japan.","DOI":"10.1109\/LED.2016.2625745"},{"key":"ref_13","unstructured":"Lauxtermann, S., and Vangapally, V. (2013, January 12\u201316). A Fully Depleted Backside Illuminated CMOS Imager with VGA Resolution and 15-micron Pixel Pitch. Proceedings of the 2013 International Image Sensor Workshop, Snowbird, UT, USA."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1109\/16.293300","article-title":"PIN detector arrays and integrated readout circuitry on high-resistivity float-zone silicon","volume":"41","author":"Snoeys","year":"1994","journal-title":"IEEE Trans. Electron. Devices"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"C06016","DOI":"10.1088\/1748-0221\/14\/06\/C06016","article-title":"A 110 nm CMOS process for fully-depleted pixel sensors","volume":"14","author":"Pancheri","year":"2019","journal-title":"J. Instrum."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2393","DOI":"10.1109\/TED.2020.2985639","article-title":"Fully Depleted MAPS in 110-nm CMOS Process With 100\u2013-300 \u03bcm Active Substrate","volume":"67","author":"Pancheri","year":"2020","journal-title":"IEEE Trans. Electron. Devices"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1016\/0168-9002(96)00194-5","article-title":"The effect of metal field plates on multiguard structures with floating p+ guard rings","volume":"377","author":"Avset","year":"1996","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2978","DOI":"10.1109\/TNS.2010.2063439","article-title":"Guard Ring Simulations for n-on-p Silicon Particle Detectors","volume":"57","author":"Koybasi","year":"2010","journal-title":"IEEE Trans. Nucl. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1215","DOI":"10.1109\/23.785736","article-title":"Study of breakdown effects in silicon multiguard structures","volume":"46","author":"Bacchetta","year":"1999","journal-title":"IEEE Trans. Nucl. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1016\/0038-1101(70)90139-5","article-title":"Measurement of the ionization rates in diffused silicon pn junctions","volume":"13","year":"1970","journal-title":"Solid-State Electron."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1537","DOI":"10.1103\/PhysRev.109.1537","article-title":"Ionization rates for electrons and holes in silicon","volume":"109","author":"Chynoweth","year":"1958","journal-title":"Phys. Rev."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1016\/S0168-9002(01)01885-X","article-title":"Extraction of bulk generation lifetime and surface generation velocity in high-resistivity silicon by means of gated diodes","volume":"477","author":"Verzellesi","year":"2002","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"817","DOI":"10.1109\/16.753724","article-title":"On the accuracy of generation lifetime measurement in high-resistivity silicon using PN gated diodes","volume":"46","author":"Verzellesi","year":"1999","journal-title":"IEEE Trans. Electron. Devices"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1088\/1748-0221\/7\/12\/C12012","article-title":"Investigation of X-ray induced radiation damage at the Si-SiO2 interface of silicon sensors for the European XFEL","volume":"7","author":"Zhang","year":"2012","journal-title":"J. Instrum."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/11\/3809\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:09:23Z","timestamp":1760162963000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/11\/3809"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,31]]},"references-count":24,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2021,6]]}},"alternative-id":["s21113809"],"URL":"https:\/\/doi.org\/10.3390\/s21113809","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,31]]}}}