Influence of Technological Parameters of the Atomic-Layer Epitaxy Process on the Uniformity of the Thickness of the Obtained Nucleation Layers GaN
One way to obtain perfect nitride structures for microelectronics is to use the atomic layer epitaxy growth method. The paper considers the influence on the growth dynamics and uniformity of the distribution of the deposited gallium nitride (GaN) layer of such process parameters as the pressure in the reactor, the flow rate of the trimethylgallium precursor and the substrate temperature in the deposition zone (growth temperature). The experiments were carried out in the original reactor in which the flow of gases to the surface of the substrates was carried out horizontally, the growth temperature in different experiments was in the range of 450-540 °C, pressure was varied from 4·104 Pa (400 mbar) up to 5·103 Pa (50 mbar), flow trimethylgallium ranged from 3 to 120 ml/min. The thickness of the layers is determined on a spectral ellipsometer. Obtained samples were studied by atomic-layer microscopy. Conditions of carrying the process for obtaining a uniform thickness of epitaxial layers of GaN on sapphire substrates have been researched.