| 摘要 |
PURPOSE:To contrive the improvement in the integrity density of a semiconductor device by forming a base layer with an opening having approximately equal two sides to an opening for forming a collector. CONSTITUTION:Openings 24-26' are perforated at an oxide film on a P type Si substrate 21, and N type layers 24, 24' are formed thereon. A resist mask 27 is coated thereon, and P type base layers 28, 28' are formed therethrough. Since the collector forming opening and the base forming opening have equal openings 25, 25', the distance between the base layers 28, 28' and the substrate 21 is self-aligned depending upon the difference in the diffusing expansion between the layers 24, 24' and 28, 28'. When the collector layers 24, 24' are formed shallow to reduce the interval a of the openings to improve the integrity thereof, the distance between the base layers 28, 28' and the substrate 21 becomes small, but the difference between the depths thereof is always retained, the distance between the bases may be reduced in c=a to secure the insulation between the base layer and the substrate in large effect. |
