GaN on Si Substrate with AlGaN/AlN Intermediate Layer

Abstract

A single crystal GaN thin film was successfully grown on a Si (111) substrate by means of atmospheric pressure metalorganic chemical vapor deposition. Though there is a large difference in thermal expansion coefficients between GaN and Si, an intermediate layer consisting of AlN and AlGaN improved the quality of GaN on Si and reduced meltback etching during growth. Pits and cracks were not observed on the substrate and a mirror-like surface was obtained. The full-width at half maximum (FWHM) of the double-crystal X-ray rocking curve for GaN(0004) was 600 arcsec. Photoluminescence measurement at room temperature for a Si-doped film revealed a sharp band-edge emission with a FWHM of 62.5 meV, which is the narrowest value reported to date.

Analysis of reaction between c+a and -c+a dislocations in GaN layer grown on 4-inch Si(111) substrate with AlGaN/AlN strained layer superlattice by transmission electron microscopy

“…25 A high-temperature AlGaN/AlN nucleation layer of thickness about 110 nm, was grown to prevent the diffusion of Ga into the Si substrate, 9 which was followed by the growth of 135 pairs of AlGaN/AlN strained layer superlattice (SLSs). 10 The SLS buffer was used to control the strain balance on the large-area wafer.…”

“…[1][2][3] GaN growth on a Si substrate is one of the most useful methods for providing large-area GaN wafers at a low cost. [4][5][6][7][8] As aresult of several breakthroughs, 9,10 an AlGaN/GaN HEMT on Si demonstrated a breakdown voltage of over 1400 V. 10 Unfortunately, the large lattice and thermal expansion mismatches between Si and GaN produce high-density dislocations in a GaN layer. [11][12][13] Decreasing the dislocation density in a GaN layer has been a major issue because the dislocations are considered to deteriorate the reliability and life of devices.…”

Heteroepitaxial Growth of High‐Quality GaN Thin Films on Si Substrates Coated with Self‐Assembled Sub‐micrometer‐sized Silica Balls

“…Prior to the GaN layer growth, 80 nm thick AlN buffer layers were deposited on SBS substrates in order to prevent meltback etching [12]. For GaN and AlN growth, trimethylgallium (TMG), trimethylaluminum (TMA), and NH 3 were used as reactant precursors and H 2 as a carrier gas.…”

“…[11] Prior to the GaN layer growth, 80 nm thick AlN buffer layers were deposited on the SBS substrates in order to prevent meltback etching. [12,13] The typical thickness of GaN epilayers after growing for 80 min was 1.4 lm. Field-emission-gun scanning electron microscopy (FEG-SEM) and optical microscopy were employed to investigate the surface morphology of the GaN epilayers on SBS substrates at different growth stages.…”

Improved MOCVD growth of GaN on Si‐on‐porous‐silicon substrates

“…The Si substrate has the advantages of low cost, large area availability, and reasonable thermal conductivity over sapphire and SiC. We have reported that an intermediate layer with high thermal stability is required to prevent meltback etching and succeeded in growing flat GaN films on Si [1,2]. However, due to the large lattice and thermal mismatches, it is still difficult to obtain high-quality GaN films on Si.…”