| 摘要 |
1,107,009. Semi-conductor devices. STANDARD TELEPHONES & CABLES Ltd. 22 Nov., 1966, No. 52154/66. Heading H1K. The junction 8 between opposite conductivity-type regions 2, 5 of a semi-conductor device, the former of which regions surrounds the latter, extends perpendicularly to the surface of, and down to, a gallium arsenide substrate 1 on which the device is formed. In the embodiment shown the N-type region 2 is formed either by epitaxial deposition of gallium arsenide, gallium phosphide or germanium on to the semi-insulating substrate 1, or by conversion of the surface of the substrate to N-type semiconductivity. The P-type region 5 is then formed by diffusion through a suitable silicon oxide mask 3, and ohmic contacts 6, 7 are applied to the P and N regions, respectively to form a diode. The region 5 may alternatively be formed by alloying a suitable dopant into the region 2. In a further embodiment a shaft is etched in the region 2 down to the substrate 1 through the oxide mask, and the second region is formed by diffusion into the exposed surface of the region 2, to form an annular P-type zone (13), Fig. 4c (not shown). The shaft is then filled with conducting material to form ohmic contact to the zone (13), annular contact to the N-type first region (2) being made as above. The annular P-type zone may alternatively be formed by the alloying of a dopant which is inserted into the etched shaft. A transistor may be made by diffusing a P-type region 5 into the N-type region 2 as described above, and subsequently diffusing a further N-type region (13), Fig. 6j (not shown), into the region (5) through a suitable mask, to form a second junction perpendicular to the surface and extending down to the substrate (1), and surrounded by the first junction. A limited P-type diffusion stage may then be used to increase the surface area of a portion of the region (5), to facilitate the application of an ohmic base contact (17), emitter and collector contacts (18, 16) also being applied to the regions (13, 2) respectively. |
