Method for fabricating AIGaN/GaN-HEMT using selective regrowth

摘要

A semiconductor body includes, on a substrate, a stack of buffer layer, UID-GaN layer overlying the buffer layer, and UID-AlGaN layer overlying the UID-GaN layer. On the surface of the UID-AlGaN layer, an insulation film is deposited and patterned. An n⁺-GaN layer is selectively regrown directly on a region of the surface of the semiconductor body other than the insulation film using the patterned insulation film as a mask without etching the surface of the semiconductor body. A portion of the selectively regrown n⁺-GaN layer corresponding to a region reserved for an ohmic contact electrode is defined and the ohmic contact electrode is formed on the region. An opening exposing a region reserved for a gate electrode is defined and formed within the insulation SiO₂ layer, and a gate electrode is formed in the region. An AlGaN/GaN-HEMT or MIS type of AlGaN/GaN-HEMT has lower contact resistance and uniform device characteristics.