| 摘要 |
973,837. Semi-conductor devices. GENERAL ELECTRIC CO. June 8, 1962 [June 12, 1961], No. 22240/62. Heading H1K. A three electrode switching device has four main layers alternating in conductivity type and has ohmic electrodes on each of the two outer layers-a portion of one of the two outer junctions is made a tunnel junction and the third electrode is in ohmic contact either with the second layer of the structure if the degenerate region of the tunnel junction is of the same conductivity type as the outer (first) layer or with the degenerate region itself if this is of the same conductivity type as the second layer. The device shown in Fig. 1 is constructed from a three ohm cm. silicon wafer which has phosphorus diffused into its faces. The wafer is then heated in steam to grow a protective oxide film on its surface. That part of the surface under which layer 6 is to be formed is either protected from oxidation or has the oxide film subsequently etched off, and boron is diffused into the exposed surface of the wafer to form the P-type layer 6. The wafer surfaces are ground and etched, or just etched, to remove the oxide film and a P+ zone 9 is formed by alloying a material such as aluminium containing 2% of boron to the wafer. Gold electrode 7 and aluminium electrode 8 are then evaporated on. These electrodes may be made of other metals such as lead and nickel and may be formed by any known method. Ohmic contact to the second layer is made by an electrode 10 consisting of any suitable material. Fig. 3 shows the characteristic curve of the device which may be made to turn on at different applied voltages by varying the potential applied between electrodes 8 and 10. In a second embodiment, Fig. 4 (not shown), the control electrode 10 is placed at a point on layer 5 opposite the tunnel junction so that current between electrodes 8 and 10 flows through layer 5 parallel to junction J E1 and varies the bias across it along its length. In a third embodiment the alloyed region 9 of the device shown in Fig. 1 is replaced by an alloyed N+ region with an ohmic contact which replaces electrode 10 and acts as the control electrode of the device. |
