HVPE fabrication of GaN sub-micro pillars on preliminarily treated Si(001) substrate

Abstract

The work reports on the chloride vapour phase epitaxy growth of a GaN film on the preliminarily treated silicon substrates of Si(001) with a 3° miscut to (011) through the buffer layer of AlN. It was demonstrated that the use of the proposed technology resulted in the formation of a transition sub-layer in the Si substrate with the thickness of ~170–200 nm, and subsequent growth on this layer led to the formation of pillar-like GaN grains with a lateral size of ~500 nm involving the thin interlayer of the AlN phase between the pillars. The epitaxial GaN film was characterised by the low value of the residual stresses calculated using the data of XRD, Raman, and PL measurements. This idea was supported by the intense photoluminescence and the short life time of the photons in the epitaxial layer. The obtained data will be utilised as an important material for the understanding of the basic foundations in the physics of GaN/AlN/Si nano-heterostructures, thus facilitating their potential applications in optoelectronics.