Growth and characterization of GaN-based structures on SiCOI-engineered substrates

Abstract Silicon carbide (SiC) still shows the best properties as substrate for the growth of GaN and its alloys but suffers from a very high price. An innovative alternative for this substrate are SiC/SiO 2 /Si (SiCOI) substrates, combining SiC and Si (silicon) substrate advantages thanks to the Smart Cut™ technology. These substrates consist of thin SiC layers (∼270 nm) bonded on (0 0 1) Si substrates. Using SiCOI substrates, up to 3 μm of GaN could be grown crack-free. The structures were investigated by atomic force microscopy (root mean square=0.86 nm), high-resolution X-ray diffraction and low-temperature (20 K) photoluminescence (PL) (FWHM (full-width at half-maximum)=4.9 meV). Electroluminescence test heterostructures consisting of InGaN/GaN multiple quantum wells (MQWs) were also deposited on SiCOI. Room temperature PL measurements resulted in a QW emission at around 440 nm with a FWHM of 7.8 nm. At electrical excitation, blue light emission was observed.