Publications by April S. Brown.

Papers Published

  1. Mishra, U. K. and Brown, A. S. and Jelloian, L. M. and Hackett, L. H. and Delaney, M. J., HIGH PERFORMANCE SUBMICROMETER ALINAS-GAINAS HEMT'S., IEEE Transactions on Electron Devices, vol. ED-34 no. 11 (1987), pp. 4 - .
    (last updated on 2007/04/14)

    The performance of long-gate and short-gate Al//0//. //4//8In//0//. //5//2As-Ga//0//. //4//7In//0//. //5//3As HEMTs fabricated on high-quality MBE (molecular-beam-epitaxially)-grown material is discussed. The device structures were grown lattice-matched to semi-insulating InP substrates. The typical layer consisted of an AlInAs buffer, followed by an undoped GaInAs channel, a thin undoped AlInAs space, a doped AlInAs donor layer, an undoped AlInAs barrier layer, followed finally by an n** plus GaInAs cap layer. The two epitaxial layer designs (wafers A & B) investigated to date differed only in the GaInAs channel thickness, 80 nm for wafer A and 40 nm for wafer B. Devices with 1. 3- mu m gate length were fabricated on both wafers. Transconductances of over 465 mS/mm at 300 K were measured on several devices on both wafers. There was no strong correlation between the channel thickness and the I-V characteristics. Devices with approximately 0. 30- mu m gate length were fabricated on wafer A. They exhibited transconductances of over 650 mS/mm at room temperature. The maximum drain current density was approimately 600 mA/mm which is twice the current density obtainable from single heterojunction AlGaAs-GaAs devices. This predicts a high fan-out capability for AlInAs-GaInAs HEMTs.