Facets formation mechanism of GaN hexagonal pyramids on dot-patterns via selective MOVPE
- Nagoya Univ. (Japan). Dept. of Electronics
Three-dimensional GaN pyramids have been successfully obtained on dot-patterned GaN(0001)/sapphire substrates by using the selective MOVPE technique. The dot-pattern is a hexagon arranged with a 5{micro}m width and a 10{micro}m spacing. The GaN structure comprises a hexagonal pyramid covered with six {l_brace}1{bar 1}01{r_brace} pyramidal facets on the side or a frustum of a hexagonal pyramid having a (0001) facet on the top. The facet formation mechanism has been investigated by observing the facet structure with the growth time. The {l_brace}1{bar 1}01{r_brace} facets are very stable during the growth. The (0001) facet growth is dominant at the initial growth but almost stops at a certain growth time and then the facet structure is maintained. The appearance of the self-limited (0001) facet is attributed to the balance of flux between incoming Ga atoms from the vapor phase to the (0001) surface and outgoing Ga atoms from the (0001) surface to the {l_brace}1{bar 1}01{r_brace} surface via migration. The longer the diffusion length of the Ga atoms on the (0001) surface is, the more the surface migration is enhanced, resulting in the appearance of the wider (0001) facet on the top.
- OSTI ID:
- 394962
- Report Number(s):
- CONF-951155--; ISBN 1-55899-298-7
- Country of Publication:
- United States
- Language:
- English
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