提出了包括有限势垒高度下反型层量子化效应以及多晶硅耗尽效应在内的直接隧穿电流模型 .在该模型的基础上 ,研究了采用不同高介电常数栅介质材料时MOSFET的栅电流与介质材料的介电常数、禁带宽度及和Si导带不连续等参数之间的关系 .所获得的结果能够为新型栅介质材料的选取提供依据 . A direct tunneling current model including the quantization of the inversion layer at the barrier height and the depletion effect of polycrystalline silicon is presented. Based on the model, the gate of the MOSFET with different high dielectric constant gate dielectric materials The relationship between the current, the dielectric constant of the dielectric material, the forbidden band width and the discontinuities of the Si conduction band, etc. The obtained results can provide the basis for the selection of the new gate dielectric material.