Characterization and All-Region Virtual-Source Modeling of 40 nm GaN HEMT Technology for High Frequency IC Design

The accurate modeling of distortion behavior in GaN-based High Electron Mobility Transistors (HEMTs) is crucial for the design of high-frequency integrated circuits (ICs). We demonstrate a virtual-source-based modeling approach to describe the DC and RF characteristics of 40 nm GaN HEMT technology. The model passes the Gummal symmetry test and is compatible with commercial EDA tools for switching GaN circuit design and simulation. The model parameters are extracted based on DC I-V and S-parameter measurements of device samples with different widths (12x50, 6x50, and 4x37.5 µm) over a wide bias and frequency range. The all-region model considers the effects of terminal parasitic impedance, self-heating, and quasi-ballistic transport, and shows excellent scalability and extrapolation accuracy by successfully predicting large- and small-signal characteristics of a 2x25 µm width GaN HEMT. With build-in physical insight, the model can help provide insights of the key nonlinearity variation contributors from a practical modeling point of view.