Ts. Zheleva et al., Pendeo-epitaxy versus lateral epitaxial overgrowth of GaN: A comparative study via finite element analysis, PHYS ST S-A, 176(1), 1999, pp. 545-551
Recent studies of the structural quality of GaN stripes grown selectively v
ia lateral epitaxial overgrowth (LEO) and pendeo-epitaxy (PE) or maskless l
ateral epitaxy, reveal that the regions of lateral growth exhibit four-to-f
ive orders of magnitude lower density of dislocations compared to the regio
ns of vertical growth, In both cases the crystallographic templates for the
lateral growth are the {11 (2) over bar 0}, {1 (1) over bar 00}, or the {1
(1) over bar 01} side facets of the GaN. The examination of the morphology
of the top surfaces. side facets, and interfaces of the LEO- and PE-GaN st
ripes with the underlying and adjacent interfaces, reveal their striking si
milarity with the thermally generated stress/strain gradient profiles as ca
lculated via finite element analysis. A comparison between the stress distr
ibution as a result of the mismatches in the coefficients of thermal expans
ion among the films in the structures, grouped in four types with:different
geometries will be presented: (1) conventional LEO-GaN, (II) conventional
LEO-GaN case without SiO2 layer, (III) PE-GaN mode A, and (IV) PE-GaN mode
B.