| 摘要 |
1311178 Making semi-conductor devices FERRANTI Ltd 16 Sept 1971 [19 Sept 1970] 44725/70 Heading H1K The figure shows a part-way stage in the manufacture of a read-only memory store and depicts one isolated pocket 55 of a 3 x 3 diode matrix only selected diodes of which are to be connected between the input and output lines. The three regions 58 form PN-junctions 11 with the epitaxial layer 55 to form three diodes associated with input line 20. This line contacts the layer 55 via an enhanced conductivity region 57. In forming the matrix the selected diodes are connected to output lines 30, 31, or 32 by applying a voltage pulse between the line and region across the reduced thickness portion 62 of the passivation to establish a permanent ohmic contact. The pulse is of greater magnitude than any pulse used in operation of the store, but is not so large as to damage the junction. In the example, the body is of silicon, the passivation 60 is of silicon oxide, and the contact material is aluminium or " Nichrome" (Registered Trade Mark). The method of connecting selected cells may be applied also to transistors or multi-component bi-stable elements. |
