Scaling Rules for Multi-Finger Structures of 0.1-μm Metamorphic High-Electron-Mobility Transistors

We examined the scaling effects of a number of gate_fingers (N) and gate_widths (w) on the high-frequency characteristics of 0.1-μm metamorphic high-electron-mobility transistors. Functional relationships of the extracted small-signal parameters with total gate widths (wt) of different N were proposed. The cut-off frequency (fT) showed an almost independent relationship with wt; however, the maximum frequency of oscillation (fmax) exhibited a strong functional relationship of gate-resistance (Rg) influenced by both N and wt. A greater wt produced a higher fmax; but, to maximize fmax at a given wt, to increase N was more efficient than to increase the single gate_width.