Sensitivity of Unbiased Commercial P-channel Power VDMOSFETs to X-ray Radiation

The effect of X-rays on the p-channel power vertical double diffused metal-oxide-semiconductor field-effect transistors (VDMOSFETs) was investigated. The VDMOSFETs were irradiated without gate polarization using three different Xray beams. Due to the polyenergetic nature of X-rays, their effect is much more complex than the effect of gamma radiation on transistors. The influence of X-rays on threshold voltage shift
$(\Delta V_{T})$
and on the creation of fixed traps (FTs) in gate oxide and on switching traps (STs) near and at oxide/semiconductor interface was analyzed. The effect of STs on
$\Delta V_{T}$
is more significant than in the case of y-radiation. The obtained results showed that the sensitivity to radiation depends on the radiation energy, and they are in accordance with the theoretical predictions.