N- and P- type Doping in Al-rich AlGaN and AlN

摘要

Attaining a high conductivity in both p-type and n-type Al-rich AlGaN epitaxial films is necessary for highly efficient deep-UV emitters. While reliable n-type conductivity has been demonstrated in Al_xGa_(1-x)N up to x < 0.8, achieving a reasonable p-type conductivity is a challenge even in Ga-rich AlGaN films. As one increases the x in Al_xGa_(1-x)N, several point defects and charge compensators appear in the epitaxial film. This report reviews recent observations on doping, conductivity, point defect control of Al-rich AlGaN films. Discussions on activation energy, state-of-the-art epitaxial material quality, contact formation and surface treatments are also presented.