| 摘要 |
Multilayer metal contact on a semiconductor substrate of one conductivity type (a), where one layer is Au. The novelty is that the substrate is coated with Au, followed by a second Au layer contg. the dopant responsible for conductivity (a); the second layer is followed by a third Au layer, then Ni and finally Ag. The substrate is pref. n-type, whereas the second layer contains max. 1% of the dopant, viz. Sb, P or As. The Au layers are pref. successively applied by vapour deposition, and the assembly heated above the eutectic temp. of Au and the substrate, esp. while applying a glass passivation layer at 500-700 degrees C. The layers of Ni and Ag are then applied by vapour deposition; or a thick Ag layer is applied by electroplating to another substrate zone, and then layers of Ni and Ag by vapour deposition. The contact is esp. useful for DH-diodes encapsulated in glass. The contact has good adhesion and withstands the high temp. needed when using the molten glass. |
