Accurate modeling of the source resistance in modulation-doped FETs

A distributed multiple-layer transmission line (MTL) model has been developed for the source and drain ohmic contacts of modulation-doped FETs. Results based on the authors' model clearly demonstrate that the source resistance in MODFETs cannot be estimated simply from a knowledge of the behavior of the series resistance in nongated TLM test structures. Differences between the results based on the MTL model and those obtained from the previously used lump-element contact end-resistance (LECR) model are explained.<
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