Misfit Stress Relaxation in α-Ga2O3/α-Al2O3 Heterostructures via Formation of Misfit Dislocations

A theoretical model of misfit stress relaxation in film/substrate alpha-Ga2O3/alpha-Al2O3 heterostructures with allowance for lattice anisotropy of heterostructure materials is proposed. Nucleation of misfit dislocations as a result of basal or prismatic slip in alpha-Ga2O3/alpha-Al2O3 heterostructures with different film orientations is considered. Dependences of critical thickness h(c) (above this thickness nucleation of misfit dislocations is favorable) on angle theta between the polar c-axis and the normal to the film growth plane for alpha-Ga2O3/alpha-Al2O3 heterostructures are obtained. It is shown that consideration of elastic constant C-14 in these models of relaxation in alpha-Ga2O3/alpha-Al2O3 heterostructures is unnecessary.

Automated summary

A theoretical model for misfit stress relaxation in film/substrate alpha-Ga2O3/alpha-Al2O3 heterostructures with lattice anisotropy is proposed. The nucleation of misfit dislocations due to basal or prismatic slip in heterostructures with different film orientations is considered. The dependencies of critical thickness on the angle between the polar c-axis and the normal to the film growth plane are obtained for alpha-Ga2O3/alpha-Al2O3 heterostructures.