Single crystal dielectric thin films for integrated capacitors – MOCA

The MOCA project is dedicated to the study of thin films single crystals from the perovskite family obtained on Silicon substrate by epitaxial routes. The materials developed will be Pb(Zr,Ti)O3 (PZT) with Zr/Ti=52/48 and (Ba,Sr)TiO3 (BST) with Ba/Sr=70/30. Three different deposition techniques will be performed: Molecular Beam Epitaxy (MBE), sol gel and Pulsed Laser Deposition (PLD). The targeted proofs of concept are three fold: acoustic resonators, high-K capacitors and piezoelectric actuators. The final aim of MOCA is to provide a clear status on the superiority of the epitaxial single crystal thin films compared to their polycrystalline counterpart. Four partners will be involved in MOCA. CEA LETI Minatec will be the leader of the project and will process the sol gel layers (PZT and BST) deposited on SrTiO3 (STO) buffered layers, which is mandatory to obtain single crystals on Si. LETI will also realise several proof of concepts devices: resonators with FEMTO, capacitors and piezoelectric or electrostrictive actuators. He will characterize these devices. INL will bring his expertise on MBE to the consortium. He will prepare the template Si wafers with the STO layer and will work specifically on this template layer. He will also prepare BST active layers in order to compare their properties to the one obtained with the other techniques. A demonstrator will be done by the partners (actuators or/and resonators). INL will provide the template layers to the partners. SPMS will work on the PLD route as it is also a recognized way to obtain single crystals as thin films. He will also help the consortium to characterize the structural behaviour of the layers deposited. FEMTO will realize resonators and characterize them. The consortium is very complementary on this dedicated topic of perovskite single crystal on Si. Finally, ST Tours, industrial with a long experience of integrating PZT capacitors with Si, will elaborate specifications and will test the capacitors based on single crystals perovskite in the framework of the MOCA project. The partners have already several common projects and developed the know-how to work together for a long time.