Novel Epitaxy Between Oxides and Semiconductors - Growth and Interfacial Structures
Abstract
The cubic gamma-Al2O3 and Si have significantly different atomic structures and lattice constants. The lattice constant of γ-Al2O3 is 7.91? and that of Si is 5.42 ?. Matching the two lattices over a unit cell dimension will result in a greater than 30% lattice mismatch. It is intriguing that a highly ordered epitaxial growth was obtained in an unusually large mismatch for a hetero-epitaxial system. High-quality single-crystal Sc2O3 films a few nanometer thick have been grown epitaxially on Si (111) despite a huge lattice mismatch. The films have the cubic bixbyite phase with a remarkably uniform thickness and high structural perfection. The bulk lattice constants of Si (5.43 ?) and Sc2O3 (9.86 ?) are mismatched by 9.2 % (relative to the doubled Si unit cell dimension). It is intriguing that a highly ordered epitaxial growth was obtained with this unusually large mismatch. It is demonstrated that epitaxial GaN layers are grown on substrates of c-plane sapphire or Si (111) wafers with gamma-Al2O3 or Sc2O3 buffer layers. Even though the of line widths of GaN grown on c-plane sapphire is smaller, the crystalline quality of the GaN grown on Si(111) with buffer layers are observed to be impressively good.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 16, 2007
- Accession Number
- ADA473102
Entities
People
- Minghwei Hong
Organizations
- National Tsing Hua University