| 摘要 |
Semiconductor heterojunction structure, i.e. what is also referred to as a heterostructure, especially for a high electron mobility transistor (HEMT), comprising a substrate (4) and a stack of at least three buffer layers made of the same semiconductor of wide bandgap EG1 based on a nitride of column, namely an unintentionally doped first buffer layer (6), a second buffer layer (8) and an unintentionally doped third buffer layer (10), an unintentionally doped intermediate layer (11) and a barrier layer (12) that is placed on the intermediate layer (11), said barrier layer (12) being made of a semiconductor of wide bandgap EG2 based on a nitride of column III; the second buffer layer (8) has a constant p+-type dopant concentration through all or some of its thickness; and the third buffer layer (10) has a first unintentionally doped region (16) right through its thickness and at least one second region (18) adjacent said first region with an n+ doping surrounding the first region (16). |
