Quantitative study the effect of 60Co on S3N4/SO2/Si capacitors via capacitance-voltage model

Two kinds Si3N4/SiO2/Si capacitor were fabricated in this work, firstly. Then the two kinds Si3N4/SiO2/Si capacitors were irradiated by 60Co at five radiation doses level (0, 1·103, 2·103, 3·103, 4·103 Gy(Si)). Because voltage dependent capacitance is the key measurement method in determining the electronic property of microelectronic materials, capacitance-voltage of two kinds Si3N4/SiO2/Si capacitors was measured before and after radiation. To quantitative study the effect of 60Co on S3N4/SO2/Si capacitors, an available capacitance-voltage model was applied to generate theoretical curves of experimental results. The fitting results agree very well with the observed curves (capacitance versus voltage). The quantitative relationship between radiation doses and carrier induced by 60Co on unit area was estimated due to this model is integrable. Another objective of this work was to identify the mathematical relationships between radiation doses and function coefficients corresponding to every experimental curve. Based on the calculation results from the non-linear curve fitting method, the radiation dose-dependent the function coefficient was theoretically explained, successfully. It is also appropriate to use function coefficient which mathematical link radiation dose to the parameters of the model in forecasting experimental C–V before one radiation dose is applied. •Two kind Si3N4/SiO2/Si capacitors were fabricated.•Capacitance-voltage of two kind Si3N4/SiO2/Si capacitors was measured before and after radiation.•An available capacitance-voltage model was applied to generate theoretical curves of experimental results.•The quantitative relationship between radiation doses and carrier induced by 60Co on unit area was estimated.•Forecasting experimental C–V before one radiation dose is possible.