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/SiO2/Si (SiCOI) substrates, combining SiC and Si (silicon) substrate advantages thanks to the Smart Cut(TM) technology. These substrates consist of thin SiC layers (similar to270 nm) bonded on (001) Si substrates. Using SiCOI substrates, up to 3 pm of GaN could be grown crack-free. The structures were investigated by atomic force microscopy (root mean square=0.86nm), high-resolution X-ray diffraction and low-temperature (20 K) photoluminescence (PL) (FWHM (full-width at half-maximum) = 4.9meV). Electrolurninescence 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. (C) 2004 Elsevier B.V. All rights reserved.