PFI:AIR - TT: Lateral Field Excited Acoustic Wave Sensor for Monitoring Thin Film Properties in Solid State Devices

University Of Maine, Orono ME

Investigators

Abstract

This PFI: AIR Technology project focuses on translating research in lateral field excited (LFE) acoustic wave devices to fill the continuing need for improved methods of process monitoring and device metrology for manufacturing processes involving thin-film deposition. A wide range of electronic, microwave, and optical devices that use these thin films are commonplace in existing and future computers, automobiles, mobile communication systems (cell phones), etc. The capability of accurately monitoring thin film properties such as film thickness, mass, viscosity, electrical conductivity and permittivity during film deposition will improve the performance of consumer electronics that depend on these devices. The features associated with the LFE monitor will provide higher sensitivity when compared to the leading competing technology, the Quartz Crystal Microbalance (QCM) in this market space, and allow electrical conductivity and permittivity monitoring which are not possible with QCM. The lateral field excited acoustic wave sensor under development is targeted for industrial factories and research laboratories which fabricate solid state electronic, microwave and optical devices that employ thin films critical to the device performance. In contrast to the commonly used QCM, the LFE device will allow the accurate and sensitive in situ monitoring of both mechanical (mass, film thicknesses and viscosity) and/or electrical (conductivity and permittivity) film properties. However, before this technology can be transitioned to a viable commercial product, two technology gaps have to be filled. First, the LFE device admittance response needs to be improved. Although the current LFE response is adequate for implementation in laboratory instrumentation, a larger change in admittance magnitude and phase is needed to realize a commercial sensor. The second gap involves the design and testing of an oscillator circuit in which the LFE device is a feedback element. In this configuration, the change in oscillator frequency becomes a direct measure of the change in film mechanical and/or electrical properties. University of Maine (UM) faculty in Electrical Engineering and Business Entrepreneurship and Fil-Tech engineers will advise undergraduates and graduate MS and PhD students in acoustic wave technology and/or business entrepreneurship necessary to realize a laboratory prototype that can be transitioned into a commercial product. In order to prepare the LFE sensor for technology transfer and commercialization, the UM Department of Industrial Cooperation will work with Fil-Tech, Inc. to develop intellectual property licensing. The project engages Fil-Tech Inc. to provide customized quartz samples and guidance critical in transitioning this technology to a viable commercial product.