Morphology and optical properties of cubic phase GaN epilayers grown on (001) Si

Abstract

Optical properties of GaN epilayers of a cubic phase are studied. We show a strong influence of the sample morphology on intensity of the edge emission. Whereas edge luminescence is reduced at the grain boundaries, red emission is spatially homogeneous.

Phase control of GaN on Si by nanoscale faceting in metalorganic vapor-phase epitaxy

“…On the other hand, the GaN on Si(0 0 1) has a severely degraded morphology which is analogous to polycrystalline film surfaces. This granular or poly-type surface is the typical surface morphology of GaN on wide-area Si(0 0 1) [7,8]. Although the original orientation of the substrate surface was (0 0 1), the GaN surface of shape of the void (or a nano-channel along the groove direction) is triangular.…”

“…2(a)is very different from that ofFig. 2(c) because of the impact of the nanofaceting on epitaxial growth[4][5][6][7][8]. The comparison ofFig.…”

“…For integration with most Si electronics technology, growth on Si(0 0 1) is much more favorable than on Si(1 1 1). However, deposition of GaN on a (0 0 1) plane results in poly-type rough surface morphology which is not suitable for most device fabrication [5][6][7][8]. Some theoretical calculations suggest a relatively small energy difference between hexagonal and cubic phases of GaN compared with other III-nitrides as one of the possible explanations [9,10].…”

Orientation-dependent nucleation of GaN on a nanoscale faceted Si surface

“…r Growth of GaN on a Si substrate offers the exciting potential of integration of GaN devices with mature Si technology. It has been known that GaN dominantly has hexagonal phase on Si(1 1 1), but can be cubic on Si(0 0 1) in epitaxial growth [1][2][3][4][5]. For integration with most Si electronics technology, growth on Si(0 0 1) is much more favorable than on Si(1 1 1).…”

“…For integration with most Si electronics technology, growth on Si(0 0 1) is much more favorable than on Si(1 1 1). Because of phase mixture at the initial stage of growth, however, deposition of GaN on Si(0 0 1) results in a rough surface morphology which is not suitable for device fabrication [4,5]. The phase mixture of GaN on Si(0 0 1) is thus another important issue for application to Si technology.…”