Preparation of the group III nitride thin films AlN, GaN, InN by direct and reactive pulsed laser ablation.

The methods of preparation of the group III nitrides AlN, GaN, and InN by laser ablation (i.e. laser sputtering), is here reviewed including studies on their properties. The technique, concerns direct ablation of nitride solid targets by laser to produce a plume which is collected on a substrate. Alternatively nitride deposition is obtained as a result of laser ablation of the metal and subsequent reaction in an NH3 atmosphere. Optical multichannel emission spectroscopic analysis, and time of flight (TOF) mass spectrometry have been applied for in situ identification of deposition precursors in the plume moving from the target. Epitaxial AlN, GaN, and InN thin films on various substrates have been grown. X-ray diffraction, scanning electron microscopy, have been used to characterise thin films deposited by these methods.