| 摘要 |
PURPOSE:To prevent bonding of substrates and separation of gate metal, by introducing a step for depositing a heat-resisting insulating film only on the partial region of a wafer other than an ion implanted layer after the ion implanted layer is formed on the upper part, which is not overlapped on the side surface of a heat resisting Schottky electrode when said Schottky electrode is used. CONSTITUTION:A W-Al gate 2 consisting of an alloy film of W and Al is formed to a thickness of 1,000Angstrom on a GaAs substrate 1, on which an ion implanted layer 5 is provided. An SiO2 film 3 is formed, to a thickness of 500Angstrom as a heat-resisting insulating film by a sputtering method. Double-layered metal films 6 of Ti/Ni, which serve as gate-pattern machining masks, are formed on the SiO2 film 3 by an evaporation and lift-off method using resist in a photolithography step. The SiO2 film 3 and the W-Al gate 2 are etched so as to make the gate part to remain. The double-layered metal films 6 of the Ti/Ni are removed with acid solution. When a facing wafer, i. e., a GaAs substrate 4 is overlapped and annealed, a gap between the GaAs substrates 1 and 4 is limited to about 1,500Angstrom . As, which is decomposed from the two upper and lower GaAs substrates 1 and 4, is confined in this gap, and further dissociation of the As is suppressed. |
