Research on Fabrication of TaN Thin Film Resistors by Using Light Field Mask Method for Microwave Circuits

Abstract:

Photolithography and etching by using dark field mask method in the fabrication of TaN thin film resistors applied in microwave circuits exists a problem of narrow alignment window. It results in inconsistency and poor yield. The process of TaN thin film resistors fabricated with Al₂O₃/TaN/ TiW/Au multistructure by using light field mask method was mainly discussed in this paper. Overlay accuracy of multilayer microstructure and accuracy of line width and line space of TaN thin films were measured by using metallographic microscope. Nonuniformity of resistances of TaN thin film resistors was also analyzed. Research on fabrication of TaN thin film resistor using light field mask method could achieve the following technical specifications: Overlay errors of multilayer microstructure on the direction parallel to two terminal electrodes’ connectivity were zero; Overlay errors of multilayer microstructure on the direction perpendicular to two terminal electrodes’ connectivity floated within 5μm to-5μm; Line width error of TaN thin film was from-2μm to 1μm. Nonuniformity of resistances of TaN thin film resistors was also consistent with the thickness nonuniformity of TaN thin film. Compared with dark field mask method, experiments revealed that photolithography and etching by means of light field mask method had advantages of wide window of alignment, high alignment precision and good uniformity. It can be concluded that photolithography and etching by using light field mask method will be widely applied in the fabrication of TaN thin film resistors for microwave integrated circuits.

• Periodical: Advanced Materials Research (Volume 1082)
• Pages: 484-488
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1082.484
• Online since: December 2014
• Authors: Qian Tao Cao*, Wang Bin, Zhen Guo Song, Jiang Hua Long
• Keywords: Light Field Mask Method, Line Width Accuracy, Overlay Accuracy, Photolithography and Etching, TaN Thin Film

References

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