| 摘要 |
1,264,032. Transistors. FUJITSU Ltd. 3 April, 1969 [4 April, 1968], No. 17672/69. Heading H1K. The planar transistor of Figs. 1 and 8 (and of Figs. 2-7, not shown) has a grid-form emitter region 3 with the apertures in the grid shown having octagonal boundaries. The base region 2 extends to the surface through these apertures. The small circles 2a, 2b, 2g, 2p etc. show areas at which contact is to be made to the base region and circles 3a, 3b, etc. show areas at which contact is to be made to the emitter region. An insulating layer 10 (of silica or silicon nitride) is formed over the surface and apertures formed in the contact areas. An overall deposit of aluminium is applied. This is etched to remove metal around the emitter contact areas and leave a grid-form base electrode 4. Aluminium may be left in the emitter contact apertures. A second insulating film 6 (of siliconmonoxide, silica, or silicon nitride) is applied to cover all except the perimeter of the base electrode and apertures produced in this to correspond with the emitter contact areas. As shown, the emitter electrode is formed by the deposition of a silicon layer 8 and by the provision of a metal layer 9 of Au, Al, Ag, Pt, Ni, Mo, Ti, or Ta. Germanium or gallium arsenide may replace the silicon, or a metal of relatively high resistivity may be used instead. This structure effectively forms a series of emitter resistors in the apertures 8a, 8b, 8c etc. and leads to even distribution of current to the various parts of the emitter region. In variants, only the material in the apertures or only the material in the main sheet 8 need be of resistive material (and parts of the sheet carrying little current may be removed). The construction may be so modified that the emitter electrode lies under the base electrode. Since the exterior surface of the electrode structure is a plane sheet, the transistor may be mounted with its emitter (or base) electrode in contact with the header of its hermetic housing to ensure efficient heat dissipation. Reference has been directed by the Comptroller to Specification 1,193,139. |
