| 摘要 |
1287473 Planar transistors TELEFUNKEN PATENTVERWERTUNGS GmbH 27 Nov 1969 [27 Nov 1968] 58163/69 Heading H1K In the manufacture of a planar transistor both the emitter region 7 and the active base region 6 are formed by diffusion through the same mask aperture. The base contact 9 is provided on a base contact region 4 which is formed through an aperture adjacent that mentioned. Lateral diffusion ensures that the two parts of the base region meet or overlap. The two apertures are also used for the provision of the base 9 and emitter 8 contacts. The contact region 4 may be formed before, simultaneously with, or after the formation of the active base region 6 and both may be formed before or after the formation of the emitter region 7. The contact region is generally made deeper than the active base-the prior formation of the emitter region enables this result to be achieved even if both parts of the base region are formed simultaneously. If the two parts of the base region are first formed by separate diffusions, the base contact aperture is left open during the later emitter diffusion, it having been ensured that sufficiently heavy base doping is used in the contact region. In contrast to the figure shown, the base contact region may extend entirely around the active base region. Completion of the device may involve removal of the diffusion mask and the provision of new passivation. Details are given of further structural and processing variants. |
