High-quality AlN grown on Si(111) by gas-source molecular-beam epitaxy with ammonia

Abstract

Hexagonal AlN layers were grown on Si(111) by gas-source molecular-beam epitaxy with ammonia. The transition between the (7×7) and (1×1) silicon surface reconstructions, at 1100 K, was used for in situ calibration of the substrate temperature. The initial deposition of Al, at 1130–1190 K, produced an effective nucleation layer for the growth of AlN. The Al layer also reduced islands of SiNx that might be formed due to background NH3 on the silicon surface prior to the onset of epitaxial growth. The transition to two-dimensional growth mode, under optimum conditions, was obtained after the initial AlN thickness of ∼7 nm.

Micro-Raman Scattering From Hexagonal GaN, AlN, and AlxGa1-xN Grown on (111) Oriented Silicon: Stress Mapping of Cracks

“…The presence of large stresses [2,3] can promote crack generation and propagation, which are detrimental to device fabrication. The problem of cracking has been overcome by initially depositing an AlN epilayer and the reproducible growth of these materials on (111)-oriented silicon substrates without any cracking has been demonstrated [4,5]. Similar results have been recently reported for GaN grown on Si substrates [6].…”

Structure and chemistry of aluminum predose layers in AlN epitaxy on (111) silicon

“…It was recognized early on that the latter problem could be solved by using an aluminum nitride (AlN) buffer layer [7]; however the buffer, despite being single crystalline, was found to have a rough surface and poor crystal quality. Nikishin et al found that depositing a thin layer of aluminum prior to AlN growth in molecular beam epitaxy improves the quality and decreases the surface roughness of both the buffer and overgrown GaN [8,9]. It was later shown that the quality of the buffer and overgrown GaN can also be improved in metalorganic chemical vapor deposition (MOCVD) by pre-treating the substrate with trimethylaluminum (TMAl) [4].…”

Structural analysis of metalorganic chemical vapor deposited AIN nucleation layers on Si (111)

“…To prevent the formation of such amorphous layer, some researchers have carried out Al predeposition on the silicon surface during MBE growth of the AlN buffer [19][20][21]. With such a predeposition procedure, Nikishin et al [19,20] have demonstrated high quality GaN on Si(1 1 1). Although 2D growth of AlN is achieved during MBE growth, such growth mode of AlN buffer has not been observed in MOCVD.…”