The present disclosure relates to a Gallium-Nitride (GaN) based module, which includes a module substrate, a thinned switch die residing over the module substrate, a first mold compound, and a second mold compound. The thinned switch die includes an electrode region, a number of switch interconnects extending from a bottom surface of the electrode region to the module substrate, an aluminium gallium nitride (AlGaN) barrier layer over a top surface of the electrode region, a GaN buffer layer over the AlGaN barrier layer, and a lateral two-dimensional electron gas (2DEG) layer realized at a heterojunction of the AlGaN barrier layer and the GaN buffer layer. The first mold compound resides over the module substrate, surrounds the thinned switch die, and extends above a top surface of the thinned switch die to form an opening over the top surface of the thinned switch die. The second mold compound fills the opening.