Implementation of High-Power-Density [Formula Omitted]-Band AlGaN/GaN High Electron Mobility Transistors in a Millimeter-Wave Monolithic Microwave Integrated Circuit Process

• Published in: IEEE electron device letters Vol. 36; no. 10; p. 1004
• Main Authors: Fitch, Robert C, Walker, Dennis E, Green, Andrew J, Tetlak, Stephen E, Gillespie, James K, Gilbert, Ryan D, Sutherlin, Karynn A, Gouty, William D, Theimer, James P, Via, Glen D, Chabak, Kelson D, Jessen, Gregg H
• Format: Journal Article
• Language: English
• Published: New York The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 01.10.2015
• Subjects: Electronics industry; Nanotechnology
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2015.2474265

A GaN high electron mobility transistor monolithic microwave integrated circuit (MMIC) designer typically has to choose a device design either for high-gain millimeter-wave operation with a short gate length, or for high-power-density [Formula Omitted]-band operation with a much larger gate/field-plate structure. We provide the designer the option of incorporating two different devices by implementing a 0.14-[Formula Omitted] gate length GaN MMIC process capable of high-efficiency Ka-band operation while simultaneously achieving high power density in the same process flow. The key process enabler simply uses the capacitor top plate in the MMIC process as a field plate on the passivation layer. On two separate devices on the same chip using the same MMIC process flow, we demonstrate 7.7 W/mm at 35 GHz and [Formula Omitted] V on a standard [Formula Omitted]-[Formula Omitted] T-gated FET and then 12.5 W/mm at 10 GHz and [Formula Omitted] V on a [Formula Omitted]-[Formula Omitted] T-gated FET by adding a field plate. These are the highest reported power densities achieved simultaneously at [Formula Omitted]-band and Ka-band in a single wideband GaN MMIC process.