Abstract
GaN/TiN heterostructures were deposited on 4° miscut Si(111) substrates by pulsed KrF laser ablation of TiN through vacuum, followed by reactive pulsed KrF laser ablation of liquid Ga through 70-75 mTorr of microwave-activated NH3. Deposition temperatures of 950°C and 1050°C were employed for the TiN layer while 900°C was employed for the GaN layer. The targets were positioned 5 cm from the substrate and ablated by using a reimaging beamline at a nominal energy density of 3-4 J/cm2. X-ray diffraction (XRD) revealed a highly textured heterostructure with GaN(0001)//TiN(111)//Si(111) and with a rocking curve width for both GaN(0001) and TiN(111) equal to ∼ 1.1°. The mosaic spread through the TiN(001) reflection was ∼ 1.3°, whereas that of the GaN(1011) was undetectable because of low S/N. Scanning electron microscopy revealed large oriented 10 μm-sized hexagonal crystallites decorating large depressions in the TiN film with many smaller pits also present. The effect of substrate processing and TiN film processing on pit formation was explored.
Original language | English |
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Pages (from-to) | S441-S445 |
Journal | Applied Physics A: Materials Science and Processing |
Volume | 69 |
Issue number | 7 |
DOIs | |
State | Published - 1999 |