Polarization tracking in situ

ended

"The technology for the growth of thin oxide films has reached the same level of atomic control as in the case of semiconductors. Yet, in contrast to semiconductors, oxides exhibit novel phases and functionalities like magnetic or electric order or dramatic changes of electrical resistance. One such functionality is the spontaneous formation of an electric polarization, called ferroelectricity, that is considered as basis for novel types of smart devices or energy-efficient functional components in CMOS devices. The infatuating technological potential of ferroelectric oxide heterostructures drives materials scientists to master their synthesis, understanding and control. Optimizing the ferroelectric performance is tedious, however. From the post-growth invasive and destructive analysis of prototypes, conclusions are drawn on the optimum heterostructure design and growth parameters. Monitoring the heterostructures while they are assembled in the growth chamber would provide immediate and direct feedback on the relation between growth and function and could thus immensely speed up the iterative process. The present lack of the according technique poses a restricting market factor. Here we will use a laseroptical process called second harmonic generation (SHG – doubling of the laser frequency) to track the emergence of the ferroelectric state directly, during the assembly of the oxide heterostructure in the growth chamber. Probing occurs in situ, non-invasively and non-destructively throughout the deposition process. With our Proof of Concept proposal POLARIS, we will cast such ""in-situ SHG"" into the prototype for a marketable system that is simply flanged onto the growth chamber. It is a technique with a high robustness against the sometimes harsh environmental conditions of a lab or, later on, a factory hall. Its ease of use will be similar to that a laser pointer."