Understanding and controlling heteroepitaxy with the kinetic Wulff plot: A case study with GaN

Abstract

This work represents a comprehensive attempt to correlate the heteroepitaxial dynamics in experiments with fundamental principles in crystal growth using the kinetic Wulff plot (or v-plot). Selective area growth is employed to monitor the advances of convex and concave facets toward the construction of a comprehensive v-plot as a guidepost for GaN heteroepitaxy. A procedure is developed to apply the experimentally determined kinetic Wulff plots to the interpretation and the design of evolution dynamics in nucleation and island coalescence. This procedure offers a cohesive and rational model for GaN heteroepitaxy on polar, nonpolar, and semipolar orientations and is broadly extensible to other heteroepitaxial material systems. We demonstrate furthermore that the control of morphological evolution, based on invoking a detailed knowledge of the v-plots, holds a key to the reduction of microstructural defects through effective bending of dislocations and geometrical blocking of stacking faults, paving a way to device-quality heteroepitaxial nonpolar and semipolar GaN materials.

Quasi-equilibrium crystal shapes and kinetic Wulff plots for gallium nitride grown by hydride vapor phase epitaxy

“…7 and 8 are similar to those presented in the work done by Sun et al [6,7,10] From our work, there is a marked effect of carrier gas on the growth. Nucleation under hydrogen presents inconsistencies while nucleation under nitrogen carrier gas is uniform.…”

“…There are previous reports on kinetic Wulff plots of GaN, [6][7][8][9][10]. However these studies were done by MOCVD and with highly faulted and defective substrates.…”

Phase-field simulations of GaN/InGaN quantum dot growth by selective area epitaxy

“…In the growth of GaN quantum dots (QDs) and other structures by selective area epitaxy, the growth velocity can be strongly dependent on crystallographic orientation [21][22][23][24][25][26][27][28]. The growth velocity as a function of orientation can be represented schematically with the so-called v-plot, which is a plot of the growth velocity as a function of the surface orientation.…”

Effects of surface stability on the morphological transformation of metals and metal oxides as investigated by first-principles calculations

“…In addition to the thermodynamic driving forces, kinetics also plays an important role in the determination of the morphology under real growth conditions. In such a case, the approach developed by Chernov can be applied to predict the steady-state shapes of NCs [81], and different authors have developed strategies to calculate the velocity of facet growth [82,83]. It was necessary, therefore, to develop a novel strategy to construct polyhedral structures and to especially address such structural issues.…”