| 摘要 |
PURPOSE:To reduce the source resistance in an extremely effective way, by providing an insulation film of SiO2, SiNx or the like or a metal layer, holding the wafer under a vacuum, heating it to a desired temperature and then applying atoms or molecules of V family to the surface of the wafer. CONSTITUTION:An semi-insulating GaAs substrate 1 is provided thereon with an undoped GaAs layer 2, successively with an Si-doped N-type GaAs layer 3 and successively with an N-type InAs layer 4 by the growth. A part of the epitaxial layers 2-4 are removed by the photo lithography to form a mesa shape and then the mask is removed. An SiNx film 6 is deposited by the plasma CVD. An aperture 9 is then formed by means of the photo lithography and the photoresist 7 is removed. Holding a certain degree of vacuum, the temperature of the wafer is held at 500 deg.C-600 deg.C and As4 beams are applied to remove the InAs 10 in the aperture 9. Al 11 as gate metal is vapor deposited, photoresist 12 is applied thereon and apertures are provided by the photo lithography for providing source and drain electrodes. |
