半导体物理-侯艳芳 课件7-1.ppt

* * 半导体物理 SEMICONDUCTOR PHYSICS 侯艳芳 Email: houyanfang@tongji.edu.cn 重点 1、阻挡层与反阻挡层的形成 2、肖特基势垒的定量特性 3、欧姆接触的特性 第七章 金属和半导体的接触Contact between Metal and Semiconductor §7.1 金属-半导体接触和能带图Contact between Metal and Semiconductor and Band Diagram 重点 功函数 电子亲和势 接触电势势垒 阻挡层与反阻挡层 1、功函数Wm 、Ws与电子亲和势 Ec Ev Wm Ws EFm EFs E0 En Contact between Metal and Semiconductor and Band Diagram Ws En E0 Ec EFs Contact between Metal and Semiconductor and Band Diagram Ev EFm 2、接触电势差 Contact between Metal and Semiconductor and Band Diagram 接触势垒： Wm-Ws= -q（Vms+Vs） ≌- qVms Contact between Metal and Semiconductor and Band Diagram 导带底电子向金属运动时必须越过的势垒的高度：  qVD=Wm-Ws （1） 金属一边的电子运动到半导体一边也需要越过的势垒高度： qVD Ec EF Ev Contact between Metal and Semiconductor and Band Diagram 3、阻挡层与反阻挡层 Contact between Metal and Semiconductor and Band Diagram （1）金属-n型半导体接触 Contact between Metal and Semiconductor and Band Diagram （a） WmWs 电子阻挡层: Contact between Metal and Semiconductor and Band Diagram Contact between Metal and Semiconductor and Band Diagram 金属一边的势垒 半导体一边的势垒 Contact between Metal and Semiconductor and Band Diagram （b） WmWs 电子反阻挡层: Ws Wm Ev Ec E0 EFm EFs Contact between Metal and Semiconductor and Band Diagram Contact between Metal and Semiconductor and Band Diagram （2）金属-p型半导体接触 Contact between Metal and Semiconductor and Band Diagram （1）WsWm 空穴阻挡层: EFm EFs Ws Wm Ev Ec E0 Contact between Metal and Semiconductor and Band Diagram qVD=Ws-Wm xD EF Ev Ec Contact between Metal and Semiconductor and Band Diagram