Low-Temperature Electrical Performance of PureB Photodiodes Revealing Al-Metallization-Related Degradation of Dark Currents
| Autor: | Ivana Capan, Lis K. Nanver, Tomislav Suligoj, Tihomir Knezevic |
|---|---|
| Přispěvatelé: | Integrated Devices and Systems |
| Rok vydání: | 2021 |
| Předmět: |
Junctions
ultrashallow junctions Silicon Materials science chemistry.chemical_element pure boron (PureB) diodes 01 natural sciences law.invention Single-photon avalanche diodes law 0103 physical sciences Doping Breakdown voltage interface charge photodiode Electrical and Electronic Engineering Photodiodes Diode 010302 applied physics Equivalent series resistance business.industry cryogenic measurement Schottky diode Computational modeling Electronic Optical and Magnetic Materials Photodiode thin-film boron layers chemistry Performance evaluation Optoelectronics single-photon avalanche diode (SPAD) business Aluminum Dark current |
| Zdroj: | IEEE Transactions on Electron Devices IEEE Transactions on Electron Devices, 68(6), 2810-2817. IEEE |
| ISSN: | 1557-9646 0018-9383 |
| DOI: | 10.1109/ted.2021.3074117 |
| Popis: | Pure boron (PureB) deposition as the anode region of Si photodiodes creates negative fixed charge at the boron/silicon interface, which is responsible for effective suppression of electron injection from the bulk, thus ensuring low saturation/dark current densities. This mechanism is shown here to remain effective when PureB diodes, fabricated at 700 °C, are operated at cryogenic temperatures down to 100 K. Although the PureB junctions were only a few nanometers deep, they displayed the same current–voltage ( ${I}$ – ${V}$ ) characteristics as conventional deep diffused p+-n junction diodes in the whole temperature range and also maintained ideality factors close to ${n} = 1$ . Al-contacting was found to reveal process-related defects in the form of anomalous high current regions giving kinks in the ${I}$ – ${V}$ characteristics, often only visible at low temperatures. They were identified as minute Al–Si Schottky junctions with an effective barrier height of ~0.65 ± 0.05 eV. In PureB single-photon avalanche diodes (SPADs), Al–Si perimeter defects appeared but did not affect the breakdown voltage characteristics set by implicit guard rings. Low series resistance required thin B-layers that promoted tunneling. In particular, for such thin layers, avoiding Al-related degradation puts stringent requirements on wafer cleaning and window etch procedures. |
| Databáze: | OpenAIRE |
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