| 摘要 |
1,146,600. Transistors. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 14 March, 1966 [23 July 1965; 6 Aug., 1965], No. 39177/65. Heading H1K. A planar transistor has emitter and base regions of a smaller lateral area than a collector region and connected to metallic electrode areas overlying the collector region on an insulating layer. A screening layer is provided between one of the electrode areas and the collector region and is connected to the other electrode area by a metallic stripe extending over the insulating layer. The screening layer, which is separated from the overlying electrode area by the insulating layer, is a semi-conductor region isolated from the collector region in which it is formed by a PN junction formed between them. The embodiment described is an NPN silicon transistor with its emitter electrode screened and is to be used in grounded base configuration at frequencies above 500 MHz. The N type wafer is provided first with a boron-doped base region 3 and screening region 28 by diffusion through an apertured oxide layer and subsequently with two partial emitter regions 2 by indiffusion of phosphorus. Aluminium is deposited over the entire surface and selectively etched away to leave base 6 and emitter 5 electrode areas and the stripes 27 interconnecting the screening layer of the base electrode area. The base contact fingers 17 and interconnecting stripes 27 are kept in a straight line to keep the output shunt capacitance low. The transistor is completed by the provision of a collector electrode and by encapsulation. |
