Growth of III-nitrides via sublimation and metalorganic vapor phase epitaxy
Rast III-nitridov s sublimacijo in metalorgansko parno fazno epitaksijo

english

1997

volume 31, issue 6

Narodna in univerzitetna knjižnica

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 dislocations.

22.07.2011