Modeling of Threading Dislocation Density Reduction in Porous III-Nitride Layers

Abstract

In this work, we report on the results of the theoretical analysis of threading dislocation (TD) density reduction in porous III-nitride layers grown in polar orientation. The reaction-kinetics model originally developed for describing TD evolution in growing bulk layers has been expanded to the case of the porous layer. The developed model takes into account TD inclinations under the influence of the pores as well as trapping TDs into the pores. It is demonstrated that both these factors increase the probability of dislocation reactions thus reducing the total density of TDs. The mean pore diameter acts as an effective interaction radius for the reactions among TDs. The model includes the main experimentally observed features of TD evolution in porous III-nitride layers.

Modeling of Threading Dislocation Density Reduction in AlN/Al2O3 Porous Heterostructure

“…The higher the initial TD density, the more the rate of decrease of the dislocation density with increasing thickness of the porous film. Also, this conclusion coincides with the conclusion made earlier for GaN films with spherical pores [15,16].…”

“…In the previous analysis, reaction-kinetic models were proposed to describe TD density evolution in porous films, but most of them analyzed the influence of the spherical pores [15,16]. Thus, the purpose of this work is to construct the analytical and numerical models to estimate the effect of triangular pores on the thermoelastic stresses and the TD density reduction in AlN/Al 2 O 3 heterostructure.…”

“…As mentioned in Section II, pores can attract TDs, changing their line direction from the normal to the heterostructure growth plane, and, as a result, affect the TD density in the film. To describe such process, one can use the approach proposed in Refs [15,16]…”

Early Attainments of Porous Silicon Carbide Technology: a Bibliographic Digest

“…A theoretical analysis of the behavior of extended defects (micropipes and threading dislocations) in porous media of SiC and GaN was carried out in Refs. [100][101][102][103][104]. These studies supported the statement that pores within the substrate may help reducing dislocations or strain, thereby improving the properties of epitaxial layers.…”

Динамика проникающих дислокаций в пористых гетероэпитаксиальных пленках GaN

“…Тем не менее в настоящее время отсутствует пол-ное понимание влияния пористости на эволюцию ПД в заращенном слое GaN. Только в самые последние годы появились первые физические модели, развитые на основе реакционно-кинетической модели поведения дислокаций [15,16] и описывающие эволюцию плотности ПД в таких слоях [17,18].…”