Semiconductor physics

Effect of ionizing radiation on charge distribution and breakdown of mosfets

O. V. Aleksandrov^ab, N. S. Tyapkin^b, S. A. Mokrushina^ab, V. N. Fomin<sup>b

a</sup> Saint Petersburg Electrotechnical University "LETI", St. Petersburg, Russia
^b Svetlana-Semiconductors stock company, St. Petersburg, Russia

Abstract: The effect of ionizing radiation on the formation of charges at the internal SiO$_2$-Si (substrate) and external SiO$_2$-Si (gate) interfacial boundaries and on the gate breakdown of MOSFETs is studied. It is shown that with an increase in the dose of ionizing radiation near the internal interfacial boundaries, a monotonous increase of the positive charge in $p$-MOSFETs, and the accumulation of positive charges at first, and at doses above 10$^5$ rad the accumulation of negative charges in $n$-MOSFETs is observed. Near the external interfacial boundaries, at low radiation doses, positive charge accumulation is observed, and at doses above 10$^6$ rad, negative charge in both $p$- and $n$-MOSFETs is observed. It is shown that up to a dose of 10$^8$ rad ionizing radiation does not have a noticeable effect on the gate breakdown voltage in both $p$- and $n$-MOSFETs at both polarities. The absence of influence is explained by a breakdown by the mechanism of anode hole injection.

Keywords: ionizing radiation, mosfet, charge accumulation, gate breakdown.

Received: 02.09.2021
Revised: 18.10.2021
Accepted: 18.10.2021

DOI: 10.21883/FTP.2022.02.51970.9735

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