Structural characterization of GaN/AIN layers on 3C-SiC/Si(111) by TEM

In the present work 20-μ-thick GaN epilayers have been grown by hydride-chloride vapor-phase epitaxy on 1.5-inch Si(111) substrates with AlN and SiC interlayers. Silicon carbide has been obtained by an original method of solid phase epitaxy. The transmission electron microscopy analysis revealed the effect of AlN layer structure on the quality of the gallium nitride epilayer. It is established that pores with dimensions of several nanometres formed on an AlN/GaN interface favour the growth of an epitaxial weakly strained single crystalline GaN layer. A good quality of the obtained GaN epilayers (local dislocation density is about 4×l07 cm−2, average density ∼109 cm−2) is demonstrated. The silicon substrate structure features near to a SiC interlayer will be discussed.