Figures

Figure 1

Schematic of pendeo-epitaxial growth of GaN from etched GaN (1 1  0) sidewalls and over a silicon nitride mask.

Figure 2

Cross-sectional SEM of a GaN pendeo-epitaxial growth structure with limited vertical growth from the seed sidewalls and no growth on the seed mask.

Figure 3

Cross-sectional SEM of a GaN/Al₁₀Ga₉₀N pendeo epitaxial growth structure showing coalescence over a seed mask.

Figure 4

Cross-sectional TEM of a GaN pendeo-epitaxial structure showing confinement of threading dislocations under the seed mask, and a reduction of defects in the regrowth area.

Figure 5a

Micrographs taken via cross-sectional SEM of examples of masked pendeo-epitaxial growth with coalescence over and between the seed forms resulting in a single GaN layer.

Figure 5b

Micrographs taken via plan-view SEM of examples of masked pendeo-epitaxial growth with coalescence over and between the seed forms resulting in a single GaN layer.

Figure 6

Low temperature (7K) photoluminescence spectrum of a coalesced layer of pendeoepitaxial GaN grown on a GaN/AlN/6H-SiC substrate.

Figure 7

Cross-sectional SEM micrograph of a coalesced PE GaN epilayer deposited on a masked GaN/AlN/3C-SiC/Si(111) substrate.

(click for full image)

Figure 8

Double crystal XRD analysis of the tilting in the coalesced PE films.

Figure 9a

TEM selected area diffraction patterns from (a) a small section of coalesced PE GaN over a trench region and (b) a small area of PE GaN imaged from an area over the silicon nitride mask.

Figure 9b

see caption for Figure 9a

Figure 10

TEM micrograph of a GaN film grown over a silicon nitride mask. The coalescence boundary acted as a nucleation source for horizontally oriented dislocations.

Figure 11

Room temperature photoluminescence of a coalesced layer of PE GaN grown on a GaN/AlN/3C-SiC/Si(111) substrate.

Figure 12

Comparison of low-temperature (14K) PL spectra of PE GaN grown on GaN/AlN/6H-SiC and GaN/AlN/3C-SiC/Si(111) substrates.

(click for full image)

Figure 13a

GaN film grown on unmasked, submicron wide stripes of a GaN/AlN/6H-SiC(0001) substrate. No misregistry above the GaN stripes was observed.

Figure 13b

TEM micrograph of the sample shown in (a). A significant reduction in the density of threading dislocations has been obtained in the PE GaN compared to the GaN stripes.

Figure 14a

Al₁₀Ga₉₀N film grown via pendeo-epitaxy on unmasked GaN seed posts on a 6H-SiC substrate. No misregistry above the GaN seed posts is observable.

Figure 14b

TEM micrograph of the sample in (a). A significant reduction in density of threading dislocations in the pendeo-epitaxial Al₁₀Ga₉₀N compare to the GaN seed post is obvious.

Figure 15

Two-dimensional space plot of Raman line frequency of an uncoalesced PE GaN film (specifically a wing and stripe region). An increase in the line frequency represents a relaxation of strain in the material.

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Figure 16

Photoluminescence (PL) spectra taken from the wing and stripe region of an uncoalesced PE GaN film. Note the FWHM value for the wing peak is <300 µeV.

(click for full image)

Figure 17a

Coalesced GaN films grown on un-masked GaN stripes on a GaN/AlN/3C-SiC/Si(111) substrate. No misregistry above the GaN seed post was observed.

Figure 17b

TEM micrograph of the sample in (a). A significant reduction in density of threading dislocations occurred in the pendeo-epitaxial GaN compared to the GaN stripes.

(click for full image)

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