Deposition & Lithography
Quantitative Thin Film Nanomechanical and Interfacial Adhesion Characterization
A variety of thin films have to be deposited during the fabrication of electronic devices. The two most common deposition methods are physical vapor deposition (PVD) and chemical vapor deposition (CVD) due to their abilities to produce high quality, technologically advanced thin films in mass production. However, understanding, measuring, and controlling the properties of the resultant films is a complex process. Films can range from amorphous to single crystal, a single atomic layer to multilayer coatings, dense to porous, and have structural and chemical gradients, depending on the deposition conditions. Additionally, the materials being deposited along with their resulting structure and composition can lead to large changes in interfacial adhesion properties.
There is no handbook of mechanical and interfacial properties of deposited films, given the diversity of input parameters that dictate these quantities. These properties strongly depend on the details of the deposition process, details of film growth kinetics and mechanisms on the substrate, intermediate processes, and post-deposition processes. The ability to quantitatively measure mechanical and interfacial adhesion properties of ultra-thin films is of paramount importance to controlling thin film behavior and establishing process parameter limits.
Lithography is an intermediate process in electronic device fabrication. The mechanical and interfacial properties of the photoresists, as well as the potential effects of the photolithography process on the underlying deposited film structure, need to be thoroughly characterized. Understanding the mechanical properties of the resist, such as the modulus of elasticity and glass transition temperature, are needed to assure the resist structures will withstand the various forces and environmental conditions encountered during processing.
Hysitron has pioneered a comprehensive suite of test equipment and characterization techniques to enable quantitative nanoscale mechanical and interfacial adhesion measurements of thin films. Nanoindentation measurements are valuable in determining the elastic-plastic properties of thin films, and can be enhanced with dynamic measurement capabilities for viscoelastic property determination. Additional Hysitron nanomechanical testing techniques provide the ability to quantify thin film interfacial adhesion properties. The ability to rapidly measure and control these properties on the nanoscale enables the material and process technologies required for next-generation electronic devices.