| 摘要 |
PURPOSE:To reduce a soft-error rate by alpha-rays by forming a p-n junction into a semiconductor substrate region, in which charge pairs are generated by the incidence of alpha-rays, utilizing the contact potential difference of the p-n junction or applying reverse bias voltage and forming a shielding layer. CONSTITUTION:An n-type semiconductor layer 13 is shaped on the side further lower than a p-type region 12, and an inflow to an n<+> buried layer 11 of charged generated by alpha-rays is prevented. That is, charges by alpha-rays are not generated in the p-type diffusion layer region 12 when the p-type diffusion layer 12 is not more than several dozen mum thick, thus slightly flowing currents into the n<+> buried layer 11. Contact potential difference with the formation of a p-n junction is generated on the interface between the p-type region 12 and the n-type region 13, electrons in charges generated by alpha-particles are attracted to the n-type region 13, and holes are drawn to the p-type region 12 biassed at a negative value, thus extremely reducing the inflow of charges to the n<+> buried layer 11. |
