Evaluation of Funnel Models on Calculation of Ion-Induced Collected Charge

Charge funneling is a widely used description of charge collection dynamics in semiconductor devices struck by ion irradiation, but it still relies on semiempirical parameters heavily dependent upon available data, which impacts its use for device or circuit-level simulations. The objective of this article is to analyze a comprehensive dataset from low-energy heavy-ion irradiations on a p-MOSFET, varying both the linear energy transfer (LET) and ion penetration depth within the device. A novel methodology is proposed to achieve this goal by analyzing devices without prior knowledge of their parameters, using data from light ion irradiations. Statistical analysis of the data and comparisons to simulated values showed that a LET-dependent funnel length is a more accurate description of the phenomenon than the conventional constant-length approach. A new, lower value for the funnel model’s shielding parameter k was identified, and the method also allowed for determining the metal and passivation layer thicknesses of the device. These results strengthen the reliability of the funnel model, making it a more robust tool for simulation applications.