A Heavy Ion Monitor on a Chip Based on a Non-Volatile Memory Architecture -- Part II: Device Characterization & Modeling

TL;DR

This paper advances the characterization and modeling of a Heavy Ion Monitor on a Chip (HIMoC), demonstrating its potential as a passive dosimeter through experimental validation and a novel simulation framework.

Contribution

It introduces a coupled Geant4 and DEVSIM simulation workflow for modeling HIMoC responses and validates it against experimental data, establishing HIMoC as a passive heavy-ion dosimeter.

Findings

Good agreement between simulated and experimental threshold-voltage shifts.

HIMoC signal scales linearly with ion fluence, LET, and active area.

The framework models radiation-induced charge loss in non-volatile memory devices.

Abstract

Building on the demonstrated sensitivity of the Heavy Ion Monitor on a Chip (HIMoC) presented in Part I of this work, we performed additional irradiation exposures using 24.8 MeV/u beams of $^{14}$N, $^{22}$Ne, and $^{40}$Ar at the Texas A&M University Cyclotron Institute. A novel simulation workflow was developed that couples the particle-transport toolkit Geant4 with the open-source TCAD simulator DEVSIM to model the heavy-ion-induced signal in HIMoC devices. The model represents energy deposition by primary heavy ions and secondary electrons as Gaussian charge-loss profiles that produce measurable threshold-voltage shifts in the device. Good agreement between simulated and experimental $\Delta V_{\mathrm{th}}$ distributions was obtained. HIMoC was also shown to generate a signal that scales approximately linearly with a dose-like quantity proportional to ion fluence, LET, and active detector area. These results support HIMoC as a passive heavy-ion dosimeter and provide a framework for modeling the effects of radiation-induced charge loss in charge-trapping non-volatile memory devices.