37 KB2071 KB36 KB19921999199710 straniletnik:31številka:6str. 485-494ISSN:1318-0010COBISSID:70314URN:URN:NBN:SI:doc-G9Q24KKWenInštitut za kovinske materiale in tehnologijeŽelezarna JeseniceŽelezarna RavneŽelezarna ŠtoreKovine zlitine tehnologijekristaliluminiscencamikrostrukturanitridiRamanska spektroskopijarast kristalovsublimacijaGrowth of III-nitrides via sublimation and metalorganic vapor phase epitaxy| Rast III-nitridov s sublimacijo in metalorgansko parno fazno epitaksijo|Single crystals of GaN < 3 mm in length were grown by sublimation/recondensation of GaN in 760 Torr ?$NH_3$? at 1100°C. Platelets of AlN < 1 mm thick were similarly grown between 1950 and 2250°C using an Al source. Monocrystalline GaN and ?$Al_xGa_{1-x}N$?(0001)(0.05 < x < 0.96) films were grown via MOVPE on an ?$\alpha$?(6H)-SiC(0001) wafers with and without, respectively, a 1000 A AlN buffer layer. Photoluminiscence (PL) spectra of GaN showed bound and free excitonic recombinations. Selective growth of hexagonal pyramid arrays of undoped GaN and Si-doped GaN was achieved on 6H-SiC(0001)/AlN/GaN multilayer substrates using a patterned ?$SiO_2$? mask. Field emission of these arrays exhibited a turn-on field of 25 V/?$\mu$?m for an emission current of 10.8 nA at an anode-to-sample distance of 27 ?$\mu$?m. Lateral growth and coalescence of GaN have been achieved using stripes oriented along <1100> at 1100°C and a triethylgallium flow rate of 26 mmol/min. Approximately ?$10^9$? ?$cm^{-2}$? dislocations, originating from the underlying GaN/AlN interface, were contained in the GaN grown in the window regions. The overgrowth regions contained a very low density of dislocationsKristali GaN < 3 mm dolžine so bili izdelani s sublimacijo/rekondenzacijo GaN pri 760 tor. ?$NH_3$? in 1100°C. Ploščice AlN < 1 mm debeline so bile na podoben način izdelane pri 1950 do 2250°C z uporabo Al kot izvora. Monokristalni filmi GaN in ?$Al_xGa_{1-x}N$?(0001) z (0.05 < x < 0.96) so bili izdelani z MVOPE na ?$\alpha$?(6H)-SiC(0001) vaferjih z in brez 1000 A AlN bufer sloja. Fotoluminiscentni (PL) spektri GaN so pokazali vezi in proste ekscitonske rekombinacije. Selektivna rast združba heksagonalnih piramid nedopiranega GaN in GaN dopiranega s silicijem je bila dosežena na 6H - Si(0001)/AlN/GaN večslojnih substratih z uporabo vzorčastih ?$SiO_2$? mask. Prag polja emisije teh združb je imel jakost 25 V/?$mu$?m za emisijski tok 10.8 nA pri razdalji 27 ?$\mu$?m med anodo in preizkušancem. Lateralna rast in koalescenca GaN je bila dosežena z uporabo lamel orientiranih vzdolž <1100> pri 1100°C in pretoku trietilgalija 26 mmol/min. V GaN, ki je nastal v področju oken je bilo približno ?$10^9 cm^{-2}$? dislokacij, ki so izvirale iz mejne površine GaN/AlN. Področja večje rasti so imela majhno gostoto dislokacijTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of Slovenia