High-Epsilon Coatings on Gallium-Arsenide for Microwave and Millimeter-Wave Applications

Monolithic circuits have steadily advanced over the past decade making it possible now to fabricate high performance miniature subsystems in the microwave and millimeter wave range. The major drawback of these circuits to date is the lack of high-Q components. High dielectric-constant, low-loss layers show great promise to overcome this limitation. Such moderately thick layers when patterned and integrated into the GaAs substrate structure of MMIC devices could perform a number of important high-Q functions such as filters, matching transformers, delay lines, resonators for low phase noise oscillators, etc. Phase I of this SBIR has the goal to demonstrate the basic feasibility of depositing a high-Q material on GaAs, patterning it and forming a miniature low loss transmission line compatible with standard MMIC device processes. A study of possible microwave and millimeter wave applications of this technology will also be performed that will provide the basis for future deposition and process refinements and the development of miniature high-Q components during a subsequent Phase II effort. The successful development of a high dielectric constant material deposition and patterning technology will permit the integration of miniature high-Q components directly into GaAs wafers and thus greatly extend the capability of today's monolithic circuits. This technology is expected to show major benefits for mmW spaceborne communications applications where weight, size and performance are of primary importance. (See also the letter of interest for this technology supplied by Raytheon).