Paper TF-ThM2
Vacancy Ordered Screw Form (VOSF) and Layered Indium Selenide (In₂Se₃) Thin Films by Pulsed Laser Deposition

Thursday, October 23, 2008, 8:20 am, Room 302

Indium Selenide (In₂Se₃) is an interesting material in the Chalcogenide family and has long been studied owing to its applications in Photovoltaics, optical waveguides and as battery material among others. It has recently garnered even more attention since being demonstrated as a viable phase change memory material with properties that could better GST. Device applications such as these require a film growth technique that is fast, has a high throughput along with the ability to make the desired composition relatively easily. Pulsed Laser deposition is one method that meets all the above criteria and it has also been widely used for making combinatorial samples and thus any optimization study could be done faster. In this work, we report the thin film growth of In₂Se₃ by Pulsed laser deposition. Here film deposition was carried out using a 355 nm Nd:YAG laser with a short 5ns pulse width, operating at 20 Hz. Films were subsequently characterized by X-ray diffraction, X-ray photoelectron spectroscopy and Scanning electron microscopy. Both single-phase VOSF and layered In₂Se₃ have been obtained exclusively by controlling the deposition conditions and post deposition in-vacuo annealing. The deposited films were found to be uniform and highly oriented along the c-axis. Film stoichiometry and thickness were evaluated by Rutherford Back Scattering and are in accordance with the formula unit and compare well with those obtained from vapor deposited films. Out of plane conductivity measurements were carried out with films deposited on TiN/Si and showed a large difference in conductivity between the amorphous and VOSF phases thereby supporting the use of PLD for growing thin films for Phase Change memory device applications.