Growth of AlInAs/GaInAs MODFET structures on InP substrates by molecular beam epitaxy (MBE)

We have extensively studied the relationship between growth conditions and electron transfer properties during growth of AlInAs/GaInAs/InP MODFET structures by MBE. The structure quality can be successfully controlled by controlling growth surface reconstruction status via observation of RHEED patterns and the growth phase diagram of Ga_0.47In_0.93As layers. For lattice matched channel, the optimal spacer thickness was determined to be 40 Å after considering scattering and electron density loss in the channel as well as Si planar doped layer parallel conductance effect, and μ_300k and 2DEG density are typically more than 10,000 cm²/v.s. and 2.5E12 cm^-2, respectively. For pseudomorphic channel, we have compared results of two type distributions of In composition in the GaInAs pseudomorphic channel, i.e. rectangular ´Δ´ type and ´V´ type, and experiments demonstrated that ´V´ type has advantages. After optimization of growth conditions, our best MODFET structure result reaches nearly μ_300k∼3000 cm²/v.s. 2DEG≥2.5E12 cm^-2.