A New Approach To Grow Gan By Low-Pressure Mocvd Using A Three Steps Technique

A new growth approach has been investigated to grow GaN on sapphire substrates using low-pressure metalorganic chemical vapor deposition (LP-MOCVD). This technique consists of first depositing a few monolayers of AIN on nitrided sapphire by atomic layer epitaxy (ALE), subsequent flow of Al precursor for a short time and finally the application of the conventional two-step growth method. This 'three steps technique' revealed to be a promising issue to produce device-quality GaN epilayers and quite interesting results were obtained. Indeed drastic improvements in the crystallinity and morphology of GaN films could be observed in comparison with the properties of samples prepared using the two-steps technique, with or without a pre-nitridation of the substrate.