The 2D insulator hexagonal boron nitride (hBN) has a range of promising applications, including deep ultraviolet optoelectronics, tunnel barriers in tunnel devices and protection layers for high-mobility graphene. While chemical vapor deposition (CVD) on catalytic metals like Cu and Ni is commonly used for large-area hBN growth, the transfer process leaves unacceptable residual  metal contamination for silicon-based technologies. Consequently, the growth of hBN thin films directly on compatible substrates, such as silicon-based substrates, germanium, or dielectrics, is desirable: highlighting the need for innovative approaches to fabricate 2D heterostructures. MBE and CVD techniques had been tested in order to prepare the suitable template for the synthesis. hBN was successfully grown on Si(001), Ge(001)/Si and Graphene/Ge(001)/Si. Advanced microscopy and spectroscopy techniques have been employed to investigate the morphological, crystallographic, chemical, and electrical properties of these films. Furthermore, Experimental observations have been combined with numerical investigations to draft a growth model for 2D/3D films. Indeed, the adsorption and diffusion of atomic species or small clusters can only be accurately described by quantum simulations, which are limited to systems comprising a few hundred atoms. Furthermore, the complexity of surface reactions during growth requires to consider much larger systems. To address this challenge, multiscale modelling approaches combining density functional theory (DFT) with molecular dynamics based on optimized reactive force field (ReaxFF) potential has been utilized. This approach enables the exploration of the initial stages of hBN growth, providing insights into the atomic-scale mechanisms underlying the process.