Crystal ion slicing of single crystal thin films for optical and electrical applications

Thin film technologies are the most important element in modern integrated electrical and optical circuits development. Heterogeneous thin film structures make it possible to realize multi-functional highly integrated systems. Recently a new technology called Crystal Ion Slicing (CIS), utilizing ion implantation to slice thin films from single crystal substrates, has been developed at Columbia University. This technique allows the use of existing high quality single crystal wafers to form single-crystal thin films. Thus many materials, which are otherwise very difficult to obtain in thin film form, can now be obtained for thin film device integration.; In the course of my thesis work, solutions to three issues of ion-slicing have been considered: applicability of ion-slicing to different materials, integration of sliced thin films, and device fabrication on the sliced thin films.; To achieve specific functions, particular material properties are often required. Thus, many thin film technologies have been developed for different materials. In this work, CIS has been applied for wide range of materials such as LiNbO₃, YIG, BaTiO₃ (BTO), KTaO₃ (KTO), and SrTiO₃ (STO). CIS processing was adjusted for each material to slice high quality thin films faster. LiNbO₃ slicing is well developed and large freestanding films, ∼15 x 15mm, are producible. YIG has been sliced by helium implantation and wet etching. BTO can be sliced by hydrogen implantation and heat treatment. KTO can be sliced by hydrogen implantation and wet etching. Single crystal BaTiO₃ thin films have been fabricated for the first time through this work.; The second issue considered is the size of ion-sliced films. To fabricate large thin films required for actual devices, a support wafer concept was introduced. Before slicing process, support wafers were bonded to implanted target materials to provide mechanical support for fragile films. The bonded implanted wafer was sliced into a large thin film without damage. This method solved the issue of handling a fragile freestanding thin films. More generally, wafer bonding is important for two applications: fabrication of large films and heterogeneous integration of thin films. Integration of magnetooptical devices on semiconductor platforms was demonstrated by bonding a garnet crystal on a semiconductor surface. Two bonding methods were demonstrated for these purposes; direct wafer bonding and anodic bonding. (Abstract shortened by UMI.)...