Abstract
We examined the effects of gate recess process conditions on the electrical characteristics of 0.1-μm-gate-length metamorphic high-electron-mobility transistors (MHEMTs) by the comparative analysis of small-signal parameters. When the wide-gate-recess method is adopted, significant reductions in gate-to-drain conductance and gate-to-drain capacitance were obtained compared with those obtained by the of narrow-gate-recess method. These differences in small-signal parameters are due to the removal of the entire n+ cap layer and corresponding dissimilarity in gate structure when the wide-gate-recess method is used. The wide-gate-recess method produced ∼1/2 drain-source saturation current and extrinsic transconductance compared with the narrow-gate-recess method. In contract to the DC performances, a markedly enhanced S21 gain of 3.5 dB and an fmax of 447 GHz were obtained from the MHEMTs processed by the wide-gate-recess method. This high fmax is responsible for the proper selection of the gate recess method for what and is one of the best data thus far reported for 0.1-μm-gate-length MHEMTs.
Original language | English |
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Pages (from-to) | 1914-1918 |
Number of pages | 5 |
Journal | Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers |
Volume | 43 |
Issue number | 4 B |
DOIs | |
State | Published - Apr 2004 |
Keywords
- Gamma-shaped-gate
- Maximum frequency of oscillation
- MHEMTs
- Narrow-gate-recess-method
- Wide-gate-recess-method