Geometric dependence of the parasitic components and thermal properties of HEMTs

Peter V. Vun, Anthony E. Parker, Simon J. Mahon, Anthony Fattorini

    Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionpeer-review


    For integrated circuit design up to 50GHz and beyond accurate models of the transistor access structures and intrinsic structures are necessary for prediction of circuit performance. The circuit design process relies on optimising transistor geometry parameters such as unit gate width, number of gates, number of vias and gate-to-gate spacing. So the relationship between electrical and thermal parasitic components in transistor access structures, and transistor geometry is important to understand when developing models for transistors of differing geometries. Current approaches to describing the geometric dependence of models are limited to empirical methods which only describe a finite set of geometries and only include unit gate width and number of gates as variables. A better understanding of the geometric dependence is seen as a way to provide scalable models that remain accurate for continuous variation of all geometric parameters. Understanding the distribution of parasitic elements between the manifold, the terminal fingers, and the reference plane discontinuities is an issue identified as important in this regard. Examination of dc characteristics and thermal images indicates that gate-togate thermal coupling and increased thermal conductance at the gate ends, affects the device total thermal conductance. Consequently, a distributed thermal model is proposed which accounts for these effects. This work is seen as a starting point for developing comprehensive scalable models that will allow RF circuit designers to optimise circuit performance parameters such as total die area, maximum output power, power-added-efficiency (PAE) and channel temperature/lifetime.

    Original languageEnglish
    Title of host publicationMicroelectronics: Design, Technology, and Packaging III
    Subtitle of host publicationProceedings of SPIE
    EditorsAlex J. Hariz, Vijay K. Varadan
    Place of PublicationBellingham, WA
    Number of pages7
    ISBN (Print)9780819469694
    Publication statusPublished - 2008
    EventMicroelectronics: Design, Technology, and Packaging III - Canberra, ACT, Australia
    Duration: 5 Dec 20077 Dec 2007


    OtherMicroelectronics: Design, Technology, and Packaging III
    CityCanberra, ACT


    • HEMT
    • MMICs
    • Modelling
    • Parasitic components
    • RF circuits
    • Thermal properties


    Dive into the research topics of 'Geometric dependence of the parasitic components and thermal properties of HEMTs'. Together they form a unique fingerprint.

    Cite this