| 摘要 |
940,443. Transistors. MULLARD Ltd. Dec. 14, 1959, No. 42433/59. Heading H1K. [Also in Division G1] In the manufacture of a transistor such as described in Specification 911,292, in which recrystallized semi-conductor regions 2, 4, Fig. 1, underlie metallically conductive resolidified alloy regions 1, 3, etching is continued in successive steps to the line 20a to undercut the resolidified regions until the area of contact between the recrystallized and resolidified regions is reduced to not more than one half of the original area of contact, preferably not more than one quarter, in order to reduce the inter-electrode capacitance. During etching the slot 12 between the two alloy regions is protected by polystyrene lacquer 13 applied as a solution in ethyhnethylketone. The lacquer 13 is then removed, the whole body etched and the regions 1, 3 covered in polystyrene lacquer 14 which penetrates to the undercut areas. Cerric black resist in acetone may be used instead of polystyrene in ethylmethyl ketone. Nickel wires 9, 10 soldered to the regions 1, 3 form the base and emitter connections. Nickel wire 11 forms a connection to the resolidified and recrystallized base regions 7, 8. Main body 6 consists of P-type germanium crystal of resistivity 2 ohm-cm., to which is alloyed an alloy of lead and 1 % antimony to form region 1, an alloy of lead, antimony and aluminium to form region 3 and an alloy of indium and gallium to form region 8. Antimony diffuses into the germanium to form an N-type region 5. The transistor produced is encapsulated. An automatic manufacturing procedure is described. The invention may be applied to a transistor in which as described in Specification 906,906, two alloy zones are provided by alloying at two separated areas of a semi-conductor body. In Fig. 7, the portions 40, 41 are removed from the resolidified layers 36, 37, e.g. with a sharp blade, and the connecting wires (not shown) then connected in position. An etch-resistant layer 38 is provided and etching is progressively effected until the full line 39 is reached. |
