HETEROJUNCTION BIPOLAR TRANSISTOR WITH TUNNELLING MIS EMITTER JUNCTION

摘要

A method and structure are provided for a high performance heterojunction bipolar transistor which is suited to compound semiconductor systems such as gallium arsenide (GaAs) and which utilises an emitter junction formed from a plurality of metal layers and a plurality of ultra-thin insulating layers. The metal layers chosen have work functions which form a tunnelling Metal-Insulator-Semiconductor Junction when deposited on top of an ultra-thin insulating layer. The insulating layer may be made from a rare-earth oxide such as gadolinium oxide (Gd2O3) which is epitaxially grown on a compound semiconductor substrate and possibly covered with a second ultra-thin insulating layer.