| 摘要 |
PURPOSE:To prevent contact resistance from being varied due to its area, by forming specific windows on an ohmic region. CONSTITUTION:A channel layer 3 and an ohmic layer 2 are formed on a surface of a GaAs semi-insulating substrate 1, and next a PCVD SiN film 4 is piled on the whole surface of the substrate. After the PCVD SiN film 4 on the surface of the ohmic layer 2 is removed, a plurality of windows 5 are formed for ohmic electrodes, and ohmic electrodes 6 of AuGe/Ni/Au are formed by the use of lift-off. An over metal 7 serving as source and drain electrodes of Ti/Pt/Au is formed so as to cover a plurality of the ohmic electrodes 6 formed on the surface of the ohmic layer 2. A gate electrode 8 is formed to complete a field effect transistor. Contact resistance becomes independent of Wg by forming ninety ohmic windows of 2mum or 4mum when a gate width is Wg=100mum, for example, and so by forming the ohmic contact only on the window part.
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