Comparison of the properties of GaN grown on complex Si-based structures

With the aim of investigating the possible integration of optoelectronic devices, epitaxial GaN layers have been grown on Si(111) semiconductor-on-insulator (SOI) and on Si∕CoSi2∕Si(111) using metalorganic chemical vapor deposition. The samples are found to possess a highly oriented wurtzite structure, a uniform thickness, and abrupt interfaces. The epitaxial orientation is determined as GaN(0001)∕∕Si(111),GaN[112¯0]∕∕Si[11¯0], and GaN[101¯0]∕∕Si[1¯1¯2], and the GaN layer is tensilely strained in the direction parallel to the interface. According to Rutherford backscattering/channeling spectrometry and (0002) rocking curves, the crystalline quality of GaN on Si(111) SOI is better than that of GaN on silicide. Room-temperature photoluminescence of GaN∕SOI reveals a strong near-band-edge emission at 368 nm (3.37 eV) with a full width at half-maximum of 59 meV.