A DELTA-DOPED GAAS GRADED INXGA1-XAS/GAAS PSEUDOMORPHIC STRUCTURE GROWN BY LOW-PRESSURE METAL ORGANIC-CHEMICAL VAPOR-DEPOSITION

A delta-doped GaAs/graded In(x)Ga(1-x)As/GaAs pseudomorphic structure grown by low-pressure metal-organic chemical vapor deposition was demonstrated for the first time. The graded In(x)Ga(1-x)As layer in which the composition x ranged from 0.25 to 0.20 was strained to obtain a pseudomorphic structure. Furthermore, a delta-doped high-electron mobility transistor (delta-HEMT) employing a graded In(x)Ga(1-x)As layer was successfully fabricated. Due to better electron confinement and lower interface roughness scattering, the present structure reveals higher saturation current density, higher transconductance, and higher product of mobility and two-dimensional sheet density as compared to those of conventional HEMTs which were also fabricated by the same system and procedure.