Materials Analysis of Ion-Exfoliated Metal Oxides Richard M. Osgood DMR - 0405145

1. Materials Analysis of Ion-Exfoliated Metal Oxides Richard M. Osgood DMR - 0405145 Metal oxides such at LiNbO3 and SrTiO3 have elicited considerable interest because their unique dielectric properties make them ideal candidates for a number of integrated electronic and optoelectronic device designs. One major limitation on their use is the difficulty in forming them into thin films and thus allowing integration with other materials. A number of techniques have been proposed to address this thin-film problem and to extend the utility of the materials. One of these techniques utilizes ion implantation; the implanted ions (e.g., He+) can be used to exfoliate a thin film form the top surface of the material (crystal ion slicing). The goal of this study is to understand the physical processes involved in this deep-implantation exfoliation of single-crystal metal oxides. Our current focus is to determine how implantation causes local stressing of the crystal lattice, and how that stress is affected by annealing. This stress is used to obtain spatially selective etching. We have also shown that a combination of anodic bonding and implantation can be used to fabricate pre-patterned thin films of SrTiO3, and to integrate the film onto a Si platform. Our studies use advanced ion-beam characterization techniques, such as Rutherford Backscattering/Channeling and Nuclear Reaction Analysis, and synchrotron XRD, via collaboration with SUNY-Albany and Brookhaven National Laboratory, respectively. Rutherford Backscattering / Channeling: Reveals Lattice Stress and Displacement by Ion Implantation Nuclear Reaction Analysis: Localized Lithium Depletion Following Ion Implantation Maximized lattice stress for 250 ºC anneal Similar lattice stress for different implant energies, anneal methods 3% Li depletion inside Implant layer Annealing Enhances Local Stress to Promote Ion Slicing

2. Materials Analysis of Ion-implanted Optical Oxides Richard M. Osgood DMR - 0405145 Commercial Needs Growth of thin-film oxides for integrated electronics and optoelectronics is currently not “in hand”, thus presenting low-quality deposited films. Ion-implantation offers a solution in the form of Crystal Ion Slicing (CIS). CIS is a process for removing a thin layer of material from a crystal by following ion-implantation with selective heat treatments and chemical etching. We have shown that this technique can produce device-quality films for multiple applications. By extending our understanding of the implantation process, we can improve size, quality and durability of the films CIS provides, creating films large enough to support, say, entire integrated photonic circuits. In addition, we are extending our integration capability, showing how CIS films can be bonded to and interact with a semiconductor platform. Pre-patterned SrTiO3 films fabricated through anodic bonding and ion slicing Training and Education This program supports extensive collaborations with SUNY-Albany (Prof. Bakhru) and The BNL (Condensed Matter and Materials Science Department). As a result the students involved have all worked at each of the institutions here for their research. Several students have been involved: Ryan Roth (Columbia), Djordje Djukic (Columbia), and Yoo-Seung Lee (Columbia), and Bryan Laulicht (SUNY-Albany), Liqi Wu (SUNY-Albany), Sasha Bakhru (SUNY-Albany), Lakshmanan Vanamurthy (SUNY-Albany), and Sang Hoon Lee (SUNY-Albany).