Initial stage of MBE-epitaxy processes of InN on c-plane GaN template and successful p-type doping were studied. It was found that InN epitaxy proceeds through SK-mode and 1-ML-thick InN can be coherently grown on GaN. Successful p-type doping of InN was achieved by Mg doping levels from 10(18) to about 3 x 10(19) cm(-3). Overdoped Mg's introduced new donors in InN resulting in n-type conduction. Novel structure InN-based QWs consisting of coherent 1-ML-thick InN wells embedded in GaN matrix were proposed and fabricated. It was confirmed that extremely fine structure InN QWs with quite sharp and flat hetero-interface were fabricated by self-limiting growth mode under In-polarity growth regime at remarkably higher growth temperatures up to 650 degrees C. (C) 2008 Elsevier B.V. All rights reserved.