Extraction of the Inversion and Accumulation Layer Mobilities in n-Channel Trench DMOSFETs

摘要

A new method to extract both the inversion and accumulation layer mobilities of electrons in n-channel trench double-diffused MOSFETs (DMOSFETs) is proposed and implemented for the first time. First, a model is developed for the on-resistance of the n-channel trench DMOSFET. This on-resistance model is fitted to the experimental data measured from an experimental n-channel trench DMOSFET by the method of linear least squares fitting. A very good fit is obtained such that the average percentage error between the model curve and the experimental on-resistance is less than ±1%. The fitting parameters obtained are used to calculate the inversion and accumulation layer mobilities as a function of a wide range of effective electric field. The calculated mobilities agree with those previously reported for conventional MOSFETs. The results are useful for optimizing the performance and reliability of the trench DMOSFETs.