| 摘要 |
1,111,663. Semi-conductor devices. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 12 May, 1965 [15 May, 1964], No. 20051/65. Heading H1K. In a junction type semi-conductor device a metal electrode extending from one region over an insulating protective layer is capacitively decoupled from the semi-conductor body by an externally connectible conductive or semiconductive layer disposed between it and the body and isolated from the latter by insulating material or a PN junction. A transistor of this type (Fig. 1) is formed by oxidizing an N-type silicon wafer, vapour depositing boron trioxide into an aperture formed in the oxide layer and diffusing it in to form the base zone 3, reforming the oxide and diffusing phosphorus pentoxide through apertures in it to form emitter zones 4. Aluminium (or nickel) is then vapour deposited over the oxide and reduced by etching to form the shielding layer 9, 10. Silicon monoxide 8 is next deposited and aluminium emitter 6 and base 5 electrodes, which are subsequently alloyed in, formed by similar techniques. Finally gold wires are pressure-bonded to the electrodes and to area 10 of the shield and the wafer soldered to a gilded fernico plate with indium-antimony solder. In an alternative device formed by similar techniques (Fig. 4, not shown) two shielding layers in the shape of P-type layers formed in the wafer before or at the same time as the base zone are used, with portions exposed for attachment of electrodes. Although emitter and base electrodes are both shielded in the above devices it is only essential for the emitter or base respectively to be shielded according to whether the transistor is to be used with the base or emitter earthed. |
