In-situ Mass and Elasticity Monitoring of Emerging Materials at High Temperature

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The semiconductor industry has successfully moved towards smaller-scale devices due to continuous improvements in our ability to characterize emerging materials at the nanoscale. Highly sophisticated, expensive and standard characterization tools like scanning electron microscopy (SEM), scanning tunnelling microscopy (STM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) are typically used ex-situ (after material growth/deposition) and operate close to ambient temperature. One of the key barriers to up scaling the applications of new/emerging materials is to perform in-situ characterization and provide real-time control over material properties during processing. The in-situ material characterization becomes more challenging for materials deposited/grown at extremely high temperatures (above 900 K). One such example is performing in-situ gravimetric and mechanical measurements on monolayer graphene films produced using chemical vapour deposition on transition metals at 1200 K. The existing methods are not sufficient to operate under high temperatures and typically depend on manual transfer of graphene flakes after growth to the surface of sensor or dummy substrates for further analysis. The manual transfer process is prone to surface contamination and changes to material properties, thus compromising sample integrity. Therefore, there is an imminent need for in-situ material characterization to ensure reliability, suitability for a particular application and in turn provide better control during thin film growth of emerging nanomaterials (including 2D materials).The challenge is to look beyond the existing expensive methods and provide a robust, low-cost, easy-to-integrate, and real-time monitoring solution similar to a quartz based thickness monitoring with high temperature operation capabilities. In the proposed work, we will explore the use of a micro-machined double paddle oscillator geometry as in-situ mass and elasticity monitoring sensor. This work will also explore physics (using finite element methods) behind decoupling mass and elastic measurements using a special torsional resonance mode of the oscillator.