Among them a better quality beam can be easily obtained from the thermionic cathode but the emission current density of the electron is relatively low the cathode is short life due to an easily cathode poisoning and the cost is expensive .

其中， 热阴极获得的电子束的束流品质较好，但发射 电流密度相对较低，阴极容易中毒，寿命较短，而且成本高。

The simulation results show that the proposed method has the advantages of greater accuracy and adaptability to SiC Schottky contacts in high fields over the WKB approximation . It also can seamlessly treat thermionic emission and tunneling current .

结果显示该方法比WKB近似更精确，同时也更适合工作在高场条件下的SiC材料，并且能够连续地计算 热 电子发射电流和隧穿 电流。

Finally our simulation result shows that conventional SOI SBSD-MOSFET can effectively suppress thermionic emission leakage current but it still can not suppress tunneling leakage current .

最后，我们的模拟发现，普通SOI结构SBSD-MOSFET能有效阻挡来自源结的 热 电子发射泄漏 电流，但仍不能阻挡来自漏结的隧穿泄漏电流。

Usually only the thermionic cathode and the field emission cathode have access to such the high emission current of the electron beams .

通常只有 热 致 电子 发射 阴极和场致 电子发射阴极能够获得如此大的 电流强度的电子束。

The proposed model has the advantages of more universality more suitability for SiC in high-field application and seamless calculation of thermionic emission and tunneling current . ( 2 ) The study on the theoretical model of SiC SBSD-MOSFET .

该模型具有更大的普适性、更适合工作在高场条件下的SiC材料，并且能够连续的计算 热 电子发射电流和隧穿 电流。（2）SiC肖特基势垒源漏MOSFET的理论模型研究。