A Theoretical Calculation of the Impact of GaN Cap and $hbox{Al}_{x}hbox{Ga}_{1-x}hbox{N}$ Barrier Thickness Fluctuations on Two-Dimensional Electron Gas in a $hbox{GaN}/hbox{Al}_{x}hbox{Ga}_{1-x}hbox{N/GaN}$ Heterostructure

摘要

The electron mobility in a 2-D electron gas in a $hbox{GaN}/hbox{Al}_{x} hbox{Ga}_{1-x}hbox{N/GaN}$ heterostructure limited by GaN cap-thickness-fluctuation (CTF) and $hbox{Al}_{x}hbox{Ga}_{1-x}hbox{N}$ barrier-thickness-fluctuation (BTF) scattering is calculated considering the strong spontaneous and piezoelectric polarization. The calculated results reveal that the electron mobility limited by CTF and BTF scattering is lower than that limited by interface roughness scattering if the $hbox{Al}_{x} hbox{Ga}_{1-x}hbox{N}$ barrier layer is thin enough (several nanometers).