As one of the approaches to improve p-HEMT, we studied the effect of misorientation of GaAs substrates on the surface morphology, structure, and electrical properties of pseudomorphic heterostructures, as well as the parameters of transistors based on them. In a single technological cycle, heterostructures were formed on vicinal substrates with (100) orientation and misoriented by 2o to (110) by the method of MOCVD (MOCVD) in a single technological cycle. It has been established that on misoriented substrates, the growth of structurally consistent and stressed epitaxial layers occurs according to a layered-step mechanism with the formation of macrosteps. On vicinal substrates, the formation of monatomic growth steps was observed. The comparative characteristics of p-HEMT obtained using two types of substrates are considered. Keywords: GaAs/InGaAs/GaAlAs heterostructures, MOCVD epitaxy, p-HEMT, substrate misorientation, comparative characteristics of structures and p-HEMT based on them.

As one of the approaches to improve p-HEMT, we studied the effect of misorientation of GaAs substrates on the surface morphology, structure, and electrical properties of pseudomorphic heterostructures, as well as the parameters of transistors based on them. In a single technological cycle, heterostructures were formed on vicinal substrates with (100) orientation and misoriented by 2° to (110) by the method of MOCVD (MOCVD) in a single technological cycle. It has been established that on misoriented substrates, the growth of structurally consistent and stressed epitaxial layers occurs according to a layered-step mechanism with the formation of macrosteps. On vicinal substrates, the formation of monatomic growth steps was observed. The comparative characteristics of p-HEMT obtained using two types of substrates are considered.

Using atomic force microscopy, we studied the elementary processes of growing (Al, Ga, In) As heterostructures on misoriented GaAs (001) substrates by the method of MOC hydride epitaxy under reduced pressure. It was established that the growth of the epitaxial layers of GaAs and AlGaAs occurs according to a layered mechanism with the formation of macrosteps. The growth of pseudomorphic InGaAs / GaAs (001) layers also occurs by a layered mechanism with the formation of macrosteps. However, if the thickness of the pseudomorphic InxGa1-xAs / GaAs (001) layer exceeds a certain critical value depending on the molar fraction of InAs in the composition of the solid solution (x), the formation of growth defects in the form of three-dimensional islands, the density of which increases with increasing thickness, is observed on the surface of the InGaAs layer InGaAs layer. The formation of three-dimensional InGaAs islands is associated with the relaxation of elastic stresses in the pseudomorphic InGaAs / GaAs (001) layer according to the Stranski-Krastanov mechanism. Keywords: gallium arsenide, AlGaAs, InGaAs, MOC hydride epitaxy, defect formation, Stranski-Krastanov mechanism.

Elementary processes involved in low-pressure metalorganic compound hydride epitaxial growth of (Al, Ga, In)As heterostructures on misoriented GaAs(001) substrates have been studied using atomic force microscopy. It has been found that GaAs and AlGaAs epitaxial layers grow by a step–layered mechanism with the formation of microsteps. Pseudomorphic InGaAs/GaAs(001) layers also grow by this mechanism with the formation of macrosteps. However, if the thickness of the InxGa1 –xAs/GaAs(001) pseudomorphic layer exceeds some critical value that depends on molar fraction x of InAs entering into the solid solution, growth defects in the form of 3D islands are observed on the surface of the InGaAs layer with their density increasing with thickness of the InGaAs layer. Three-dimensional InGaAs islands grow owing to elastic stress relaxation in the InGaAs/GaAs(001) pseudomorphic layer by the Stranski–Krastanov mechanism.