| 摘要 |
1,188,872. Semi-conductor devices. HITACHI Ltd. 19 Jan., 1968 [20 Jan., 1967], No. 3017/68. Heading H1K. The surface of a PNPN device is provided with two films of passivating material, the film in the region of a forward blocking junction containing a greater positive charge concentration than that in the region of a reverse blocking junction. As shown, Fig. 4, an SCR is provided with a passivating layer 16, covering the forward blocking junction J 2 , which contains positive charges to increase the breakdown voltage of this junction, and a passivating layer 18 covering the reverse blocking junction J 1 . Positive charges in layer 18 reduce the breakdown voltage of the junction so a material containing few positive charges is selected for this layer. The passivating films 16 and 18 may be silicone varnish and silicone rubber respectively. The silicone rubber may contain a filler. The film 16 may also comprise silicon oxide (SiO 2 ) produced by heating dry or in steam, by reactive sputtering or by decomposition of silane, tantalum oxide (Ta 2 O 5 ) produced by reactive sputtering, or silicon nitride Si 3 N 4 , and may be protected by a further coating. |
