RHEED studies during growth of TiN/SiNx/TiN trilayers on MgO(0 0 1)

TiN/SiNx/TiN(0 0 1) trilayers have been deposited on MgO(0 0 1) substrates using ultra-high vacuum based reactive magnetron sputtering and studied by in situ reflection high energy electron diffraction (RHEED). Depositions were carried out at 500 °C and 800 °C, with SiNx layer thicknesses between 3 and 300 Å. Here, we find that SiNx(0 0 1) layers grown at 800 °C exhibit 1 × 4 surface reconstructions along orthogonal 〈1 1 0〉 directions up to a critical thickness of ∼9 Å, where an amorphous phase forms. Growth of TiN overlayers on the reconstructed SiNx(0 0 1) layers yield RHEED patterns indicating the growth of (0 0 1)-oriented epitaxial layers with a 1 × 1 reconstruction. For the case of amorphous SiNx layers the TiN overlayers grow polycrystalline.