TEM investigations of GaN layers grown on silicon and sintered GaN nano-ceramic substrates

摘要: GaN nano-ceramics were analyzed using transmission electron microscopy (TEM), showing that these ceramics are characterized by highly disoriented grains of the linear size 100–150 nm. These used as substrates for epitaxy in standard MOVPE conditions. For comparison, layers on silicon grown similar It is shown growth anisotropic both cases. However, disorientation mismatched layer different from characterizing deposited ceramic substrate. In latter case much higher, and three dimensional nature, causing creation polycrystalline structure having large number dislocations. substrate principal due to rotation around c-axis, mosaic edge Additionally, it typical grain AlN nucleation Si smaller, order 20 two factors contribute pronounced differences later stage ceramic. Due high anisotropy an appropriately thick can, eventually, develop flat surfaces suitable construction optoelectronic electronic structures. As TEM data, this can be achieved only at cost relatively density dislocations stacking faults. The defects not observed substrates. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)