| 摘要 |
PURPOSE:To obtain a bipolar semiconductor device having high performance by forming an emitter pattern to a polycrystalline silicon film applied on a substrate, to which selective oxidation is completed, and forming a base contact and an emitter pattern in a self-alignment manner so as to be faithful to the pattern by using anisotropic etching and side-surface oxidation. CONSTITUTION:An silicon dioxide film 16, an silicon nitride film 17, a polycrystalline silicon film 18 and an silicon nitride film 19 are formed on an silicon substrate 12. Emitter patterns are shaped by photo-resists 20, and the silicon nitride film 19 and the polycrystalline silicon film 18 are removed through a reactive ion etching method. The photo-resists 20 are removed, and the left polycrystalline silicon films 18 are oxidized and silicon dioxide films 21 are grown on side surfaces. A distance between a base contact 24 and an emitter region 27 can be reduced as much as possible by the silicon dioxide film 21 by the side-surface oxidation, and an emitter forming section is hardly damaged by heat treatment in an intermediate process. |
