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在砷化镓场效应晶体管中的应用如图1所示,GaAs材料的电子迁移率高,在较低电场下具有高的漂移速度,此外与硅相比其禁带宽度宽,因此,GaAs作为微波用的材料(从可以做开关速度快的放大器件来看)是一种很有吸引力的半导体材料。把GaAs材料作成晶体管时,有几个有害的缺点。譬如,由于电子和空穴的迁移率相差很大,不宜作双极器件。在利用表面反型层作为沟道的MOSFET中,在SiO_2和GaAs的界面处会产生时间常数大的界面能级。因此,不能获得像从体内迁移率得来的那么高的增益。同时这个现象也就意味着在GaAs的表面钝化上SiO_2是不太有效的。
Application in gallium arsenide field-effect transistor As shown in Fig. 1, GaAs material has high electron mobility, high drift velocity at lower electric field and wide band gap compared with silicon. Therefore, GaAs Microwave materials (from the point of view of an amplifier that can be switched fast) are attractive semiconducting materials. There are several detrimental disadvantages when making GaAs transistors. For example, bipolar devices are not suitable due to the large difference in the mobility of electrons and holes. In a MOSFET that utilizes a surface inversion layer as a channel, a large time constant interface level is generated at the interface between SiO 2 and GaAs. Therefore, it is impossible to obtain such a high gain as the mobility in vivo. At the same time, this phenomenon means that the passivation of SiO 2 on the surface of GaAs is not very effective.