### Abstract

Ultrashort gate-length pseudomorphic high-electron mobility transistors have been modeled using a full-band Cellular Monte Carlo simulator. The RF response and the cutoff frequency f_{T} have been obtained for physical gate lengths ranging from 10 to 50 nm. These results, in turn, have been used in a transit-time analysis to determine the effective gate length in each case. By interpolation, one can make an estimate of the absolute upper limit for f_{T}, which we find to be 2.9 THz in the device studied. Importantly, the effective gate lengths are considerably shorter than the depletion lengths. Thus, in general, any estimate of f_{T} based on the latter quantity is likely too small by a quite significant amount.

Original language | English (US) |
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Pages (from-to) | 306-308 |

Number of pages | 3 |

Journal | IEEE Electron Device Letters |

Volume | 29 |

Issue number | 4 |

DOIs | |

State | Published - Apr 1 2008 |

### Keywords

- Effective gate length
- Millimeter-wave transistors
- Monte Carlo methods
- Pseudomorphic high-electron mobility transistors (PHEMTs)

### ASJC Scopus subject areas

- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering

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## Cite this

*IEEE Electron Device Letters*,

*29*(4), 306-308. https://doi.org/10.1109/LED.2008.918391