| 摘要 |
<p>Semiconductor devices are provided with dual passivation layers. A semiconductor layer is formed on a substrate and covered by a first passivation layer (PL-1). PL-1 and part of the semiconductor layer are etched to form a device mesa. A second passivation layer (PL-2) is formed over PL-1 and exposed edges of the mesa. Vias are etched through PL-1 and PL-2 to the semiconductor layer where source, drain and gate are to be formed. Conductors are applied in the vias for ohmic contacts for the source-drain and a Schottky contact for the gate. Interconnections over the edges of the mesa couple other circuit elements. PL-1 avoids adverse surface states near the gate and PL-2 insulates edges of the mesa from overlying interconnections to avoid leakage currents. An opaque alignment mark is desirably formed at the same time as the device to facilitate alignment when using transparent semiconductors.</p> |
