Mechanisms of lateral epitaxial overgrowth of gallium nitride by metalorganic chemical vapor deposition

• Published in: Journal of crystal growth Vol. 195; no. 1; pp. 328 - 332
• Main Authors: Marchand, H., Ibbetson, J.P., Fini, P.T., Keller, S., DenBaars, S.P., Speck, J.S., Mishra, U.K.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-12-1998; Elsevier
• Subjects: Applied sciences; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Deposition technology; Electronics; Exact sciences and technology; Gallium nitride; Lateral epitaxial overgrowth; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Microelectronic fabrication (materials and surfaces technology); MOVPE; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Surface structure; 68.35.Bs; Lateral epitaxial overgrowth; 81.15.Kk; MOVPE; Gallium nitride; 61.72.Ff; 81.10.−h; Surface structure; Inorganic compounds; Gallium nitrides; Epitaxy; Surfaces; Binary compounds; Crystal growth from vapors; Experimental study; Lateral growth; MOCVD; Faceting; Thin films; Morphology; Masking; Fabrication structure relation; Overlayers; III-V semiconductors
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(98)00591-0

We investigate the effect of growth temperature (1015–1100°C), growth duration (3–90
min), and pattern geometry on the lateral epitaxial overgrowth (LEO) of GaN stripes using a SiO
2-masked GaN/Al
2O
3 seed. The mask openings (5 and 10
μm) are aligned in the 〈1
1̄
0
0〉 directions and the fill factor (ratio of opening width to pattern period) is varied between 0.01 and 0.5. Vertical {1
1
2̄
0} sidewalls are observed in conditions of high temperature or high fill factor, whereas inclined {1
1
2̄
n} facets (
n≈1–2.5) are observed in conditions of low temperature or low fill factor. The set of exposed facets is roughly independent of growth duration between 3 and 90
min. We suggest that the observed morphologies result from the bonding structure of the various facets in conjunction with the local variations of the V/III ratio.