| 摘要 |
PURPOSE:To improve the characteristics and reliablity of the device by inserting a bi-directional diode is series between the gate and source of an IGFET formed to a vapor growth layer on a Si base body through double diffusion. CONSTITUTION:The bi-directional diodes 2, 2'' are simultaneously diffused and shaped when double diffusion and connected in series in order to protect the gate G of the IGFET 1' through double diffusion, and inserted and connected between the gate G and a source S. According to this constitution, the PN<+> junctions J2, J4 of the diodes are yielded when positive voltage is applied to the gate G, and double reverse dielectric resistance is shown by J2+J4. When negative voltage is applied to the gate G, junctions J1, J3 are yielded. Accordingly, reverse bias is formed by the PN<+> junctions at two positions regardless of the positive and negative of a gate electrode, and double reverse dielectric resistance is generated. When a plurality of the bi-directional diodes are connected in series, allowance is taken sufficiently in gate bias, channel resistance is minimiized, mutual conductance and drain currents are improved, and the FET can be protected. |
